How often to clear cache - G Tablet Q&A, Help & Troubleshooting

Hello all
How often should you clear cache or fix permission using CWM?
Jim
Sent from my VEGAn-TAB using XDA

Personally I do it when ever the ROM that I am on starts acting a bit quirky. Which is not very often if you are running a stable build like VeganTab, CM7 or even the Froyo ROMs that have been out for a while. If you ever see yourself loading up a bunch of apps and running them allot. Over time you might would want to clear the cache and definitely fix permissions to get things back in order.

jweir said:
How often should you clear cache or fix permission using CWM?
Click to expand...
Click to collapse
They're not something you need to do often, or even occasionally, as part of some preventive maintenance regimen.
If you switch ROMs, then you will have to clear cache. Actually, it's best to do a "wipe data/factory reset" in CWM in this case--cache will get formatted in the process.
You would want to clear cache if you upgrade the current ROM; it is better, though, to instead wipe dalvik-cache. Similarly, if you upgrade an app manually--ie. not via the Market or the usual Android update process: eg. by overwriting an app in /system/app or /data/app and rebooting the system--you might want to clear cache.
You might have to clear cache after powering on the tablet after a long (weeks, months) period of inactivity. In this case, the battery will go flat and the system will lose its date and time--going back in time, so to speak. This might, in turn,cause cached data to go out of whack--though Android should take care of this normally.
The "fix permissions" step is needed even less. This link explains why you would want to use it: Again, it might be needed after a ROM update, and not otherwise. This means that doing a fix permissions after a SD card repartition or a wipe data/factory reset step is nonsensical--the fix_permissions script operates on existing data.

Related

[Q] What kind of system maintenance does Android require?

Is there a kind of system maintenance routine necessary (or beneficial) to keep Android running in top condition? I've seen that permissions can be repaired via CWMod and Dalvik cache, etc, but what else should we do to maintain the system performance and stability, etc.?
well, idk if this helps, but tmobile told me to clear the user data every 2 months or so...
User data holds what?
I'm not sure I trust the "expertise" of a T-Mobile rep, but thanks for the response.
I've had one instance where the system told me that my DB data was getting too full and asked me to purge it manually. I removed some stuff and then I noticed that the DB data went down in Titanium Backup, but I don't know what that does either, or how to keep it cleaned out.
If you are plain stock not rooted, delete cache data as the previous poster said. There is not an specific amount of time for this, but if you feel your phone starts too lag more than usual
If you are rooted, and have CWM installed wipe cache partition, and in Advanced do Wipe Dalvik cache, nad if you want wipe battery stats (Do this when your battery is full once in a while so yo get better battery reads)
I need to clear out the directories for apps from my internal SD card periodically. As I install and uninstall apps I get a bunch of directories on there that I don't need. I also like to reboot every few days to a week when my phone gets laggy.

Nandroid Advanced Restore (User Data Only) + navenedrob's format utility

Yeah, I just flashed from EB01 SC 292 to ED01 MIUIWiz after full Data, Cache, Dalvik, and voltage double wipes, and restored all my old EB01 user Data and apps over MIUIWiz, all in under 17 minutes.
Edit: adding navenedrob's utility method has cut this down to under 10 minutes, plus navigation and reboot time. See post #5
How? Just followed what the Devs have taught us, plus Nandroid Advanced Restore in CWM.
I have been doing this for every ROM I have flashed since I discovered what a Nandroid backup was.
But this is not just a Nandroid Backup. This is a partial restoration called “Restore data” under “Advanced Restore.” All in CWM recovery.
Here is the method I use:
Charge to 100% (At this point, I started the timer)
Boot to Recovery
Wipe Cache and Dalvik (and Voltage for MIUIWiz) x2
Make a Nandroid backup
Wipe Data x2
Flash the new ROM (of your choice) in CWM
Let it boot
Boot to Recovery
Select “backup and restore”
Select “Advanced Restore”
Select the Nandroid Backup file you wish to restore from (probably your latest one)
Here is where it gets cool, and less scary…
There is yet another page, with options:
Restore boot
Restore system
Restore data
Restore cache
Restore sd-ext
+++++Go Back+++++
So no sweat yet
Select “Restore Data”
Reboot completely
Turn off phone (here is where I stopped the timer at 16.5 minutes)
Charge to 100%
Boot and enjoy.
BAM! All the old data is back. On top of the new ROM. Except for stuff that no longer applies, like maybe in-ROM launchers that no longer exist.
My ROM flashing evolution path has been:
Stock
Odin DXC DB/DO tar
EC01 DB/D0 (zip i think, can't remember)
Full ED01 (Adrynalyne method, not OTA)
ComROM 1.0 zip
Evil Fascination, all variants in sequence. Zip
EB01 SC 2.9.2 zip (Why? To see if it would work. Because it means restoring ED01 Nandroid data over an EB01 ROM. Without compromising the ROM. (Thanks for the assistance with this, Lttlwing16.)
ED01 MIUIWiz
Seems to work flawlessly so far. No forced closes, no hiccups, just sweet functionality. Every time so far. And so quick, I sometimes actually have time to use my phone between flashes.
As I said, I have been doing this for just about as long as I have been flashing through CWM. Your backup may overwrite some ROM theme elements, so that is something to think about.
Any other drawbacks? Not that I have found, but…Not completely sure yet, So… You know the drill…
DO NOT TRY THIS UNLESS YOU ACCEPT FULL RESPONSIBILITY AND ARE PREPARED TO DEAL WITH THE CONSEQUENCES!! YOU MAY LOSE DATA OR FUNCTIONALITY!! YOU MAY EVEN MANAGE TO BRICK THIS THING!
But you just made a complete clean-wiped Nandroid Backup, right? So you can always restore the whole thing. Or worst case, do the Odin recovery method. (or even worse case, Heimdall).
I suspect that there is some reason that this method has not been widely promoted already. It seems unlikely that it has not been experimented with, so maybe someone can help show a newbie the error of his ways. Or we may need someone with a thorough knowledge of Fascinate ROMs to add some warnings, caveats, or guidance around potential problems, etc. But it does seem to work just fine for me, and all of the ROMs I have worked with seem smooth and stable. All my apps always work, and update properly. Unless I get stupid and screw something up.
It does seem that Android should be able to pull this off if sufficient attention is given to file structure and dependencies, and if everything data can be kept where a data only restore would look for files. I suspect that I have been having success because of the good work of all the great ROM builders and developers working to fix the Fascinate, and make our experience all that it is. So if this works for you, they are the ones that really deserve the credit and the thanks. They made it work. I just followed instructions, got curious about Nandroid Advanced Restore, and pushed the right buttons. Oh, and wrote it all down.
Wiping data and dalvik cache is kinda pointless because it gets overwritten and replaced by the restore anyway. Dalvik cache is located in the data partition, not the cache partition, ironically.
Sent from my SCH-I500 using XDA App
Well, I am expecting to learn something from posting this. So thanks. However, it raises more questions for me.
Does it mean that I never have actually needed to wipe data? I could have flashed all those ROMs without wiping data and without issues?
My understanding was that at least the cache would be re-written as needed by the new ROM, rather than trying to work with data created by the old one.
It sounds like it means that if bringing back the old data works, keeping the old data would have worked, too. So even Dalvik could have been left every time?
My thinking was that cleaning the cache and Dalvik before making the backup would mean that when restoring, they would come back blank, and not confuse the new ROM. I was under the impression that something was more likely to go wrong if all that stuff was left in there, and it was safer to bring it in later, after the ROM boots up, and give the new ROM a chance to properly recognize and deal with it.
Is there any logic in that logic? Just asking, because I really don't know. It sounds good.
If not, this thread is for educational purposes only.
But dang, either the Devs are even more awesome than we thought, or I must get lucky a lot. Because I have flashed quite a few ROMs without issues, force closes, etc.
Interested in more feedback on this process.
OK, I did have a couple of FCs of Gmail this last time flashing MIUIWiz, going from EB01 to ED01. It seemed to fix itself after I closed it twice, but I updated Gmail anyway. No repeats.
I have a new preferred method of backing up, cleaning the files, flashing new ROMs and restoring my data. Flashed MIUIWiz 111 over EF 360, the whole process taking about 10 minutes altogether plus navigation and boot time.
(Always create a clean Nandroid Backup (with wiped cache and Dalvik, possibly voltage) 4-5 minute process, not included. This should ensure that the new ROM will create its own compatible cache data after the restore.)
1. Run navenedrob's reformat utility [UTILITY]EXT4/RFS Formatter (CWM3 recovery packages) - xda-developers as a CWM zip from sd card <1 minute process.
2. Flash the new ROM in CWM <1 minute process.
3. Flash new Kernel if needed (before allowing ROM to boot) in CWM <0.5 minute process
4. Allow ROM to boot (3-4 minute process)
5. Nandroid Advanced Restore in CWM (Data only) (3 minute process)(Restores all User Data and apps)
From navenedrob: “Understand that this [format utility] will completely wipe your system, data, datadata (dbdata), and cache. This is a "full" wipe of the device.” But it also puts things back in order if they have gotten screwed up. This could be the solution to issues you are having. Thanks, navenedrob! Very cool.
If there are particularly desirable user setups in the flashed ROM, be advised they may get lost in the restore.
The only issue I seem to have is the need to update/install Gmail. Then all is smooth.
Works for me, but you may totally bork yours. You are responsible for what you decide to do.
times_infinity said:
Wiping data and dalvik cache is kinda pointless because it gets overwritten and replaced by the restore anyway. Dalvik cache is located in the data partition, not the cache partition, ironically.
Sent from my SCH-I500 using XDA App
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Click to collapse
I think that means wiping data also wipes Dalvik. So Dalvik wipe is redundant when wiping data. Good to know about the partition info. Seems to support the idea that wiping Dalvik before making the backup would ensure that when the restored data is brought back, it brings no Dalvik data with it, avoiding potential issues with the new ROM.

What does wiping dalvik cache do?

I was getting out of space on my internal phone, so I decided to clear wipe cache and dalvik cache through CWM, but I find i save a lot of space BUT some apps stop working, maybe they are lost. So was does this actually do? Why are the apps there, but can't work? :crying:
Ok, after rebooting they are actually working again, i didn't even lost any data (progress on games) but I am really concerned what does this really do??
rolo143 said:
I was getting out of space on my internal phone, so I decided to clear wipe cache and dalvik cache through CWM, but I find i save a lot of space BUT some apps stop working, maybe they are lost. So was does this actually do? Why are the apps there, but can't work? :crying:
Ok, after rebooting they are actually working again, i didn't even lost any data (progress on games) but I am really concerned what does this really do??
Click to expand...
Click to collapse
http://en.wikipedia.org/wiki/Dalvik_(software)
When you reboot, Dalvik cache and Cache are re-created. So no space saved this way.
Feanor88 said:
http://en.wikipedia.org/wiki/Dalvik_(software)
When you reboot, Dalvik cache and Cache are re-created. So no space saved this way.
Click to expand...
Click to collapse
I was wondering what wiping the Dalvik cache did, too. I installed an inverted app and someone told me I needed to wipe the Dalvik cache in order for it to remain in place after a reboot, so I did that. Now my phone says "Optimizing apps..." It must rbe e-creating the cache.
As far as I know, when a rom boots up for the first time Dalvik goes through each & every apk's & extract the Dex & put it in the cache. So probably it is a location of all apks. If dalvik cache is not wiped after a new rom is installed,dalvik cache will skip because it founds the dexed cache files attach to the directory. The result is "Force close" issues.
So wiping dalvik cache can be done without any problem many times within the same rom & that's why is shows "optiming apps" after a dalvik cache wipe.
saqib nazm said:
As far as I know, when a rom boots up for the first time Dalvik goes through each & every apk's & extract the Dex & put it in the cache. So probably it is a location of all apks. If dalvik cache is not wiped after a new rom is installed,dalvik cache will skip because it founds the dexed cache files attach to the directory. The result is "Force close" issues.
So wiping dalvik cache can be done without any problem many times within the same rom & that's why is shows "optiming apps" after a dalvik cache wipe.
Click to expand...
Click to collapse
Thanks! That's in line with my suspicion, except I didn't know when I posted my question that an apk file was nothing but a zip file that contains a dex (Dalvik executable) and a bunch of other files. Your explanation makes sense. I also noticed that if I install an individual app from a zip file using CWM Recovery, then it clears the relevant part of the Dalvik cache for me. That doesn't happen when I install an apk file directly using Root Explorer.
guys one line question i am performing "Wipe cache and dalvik-cache" will my phone internal memory be deleted ? thanks a ton
deepankarbu said:
guys one line question i am performing "Wipe cache and dalvik-cache" will my phone internal memory be deleted ? thanks a ton
Click to expand...
Click to collapse
Nop, it will not
Sent from my SK17i using xda premium
Phone didn't boot after wiping Dalvik Cache
Hi Geeks
i have an Xperia Arc S modded with Cyanogenmod JellyBean 4.1.2 Cooked ROM
i had alot of memory issues as applications keep closing whenever system runs out of memory, it is always obvious in the DSP application with the walkman in addition to visualizations inside the walkman
i searched for a solution and some told me that wiping the dalvik cache might solve the problem, so i gave it a try and rebooted in CWM recovery mode "built inside ROM" , cleared the Dalvik cache , and the phone keeps displaying the Xperia Logo without any further progress, as if it's in somekinda loop !
any idea what to do next without wiping my Data ? thank you all
BR
AMR
Koptanov said:
Hi Geeks
i have an Xperia Arc S modded with Cyanogenmod JellyBean 4.1.2 Cooked ROM
i had alot of memory issues as applications keep closing whenever system runs out of memory, it is always obvious in the DSP application with the walkman in addition to visualizations inside the walkman
i searched for a solution and some told me that wiping the dalvik cache might solve the problem, so i gave it a try and rebooted in CWM recovery mode "built inside ROM" , cleared the Dalvik cache , and the phone keeps displaying the Xperia Logo without any further progress, as if it's in somekinda loop !
any idea what to do next without wiping my Data ? thank you all
BR
AMR
Click to expand...
Click to collapse
Are you sure you only wiped the dalvik?
Sent from Myushi
clears app cache
rolo143 said:
I was getting out of space on my internal phone, so I decided to clear wipe cache and dalvik cache through CWM, but I find i save a lot of space BUT some apps stop working, maybe they are lost. So was does this actually do? Why are the apps there, but can't work? :crying:
Ok, after rebooting they are actually working again, i didn't even lost any data (progress on games) but I am really concerned what does this really do??
Click to expand...
Click to collapse
it clears the app running cache stored in os.
absolutely ..
XperienceD said:
Are you sure you only wiped the dalvik?
Sent from Myushi
Click to expand...
Click to collapse
Yes sir it's only the dalvik cache, both ways this ROM was pretty heavy and i'm not satisfied with the reboot every 2 or 3 hours of use, i will install xperia ultimate HD ROM, they say it's pretty stable and has no problems, and it has the sound enhancements i needed in the Jellybean cooked ROM
thanks for your reply
alcatel 918n
XperienceD said:
Are you sure you only wiped the dalvik?
Sent from Myushi
Click to expand...
Click to collapse
My phone also has those options built-in. If you did the dalvik only it should get back to where you have the icons. BUT, if you did something else aside from the dalvik, my guess would be goodbye data and hello to phone repairs. Please research first before you do anything on your phone. Your phone and my phone have very powerful built-in tools. It could brick the phone. I hope you did not wipe data and flash.
help! my phone's boot taking too long
i wiped /cache and dalvik cache and format /cache. it's taking took long. been waiting for almost 1 hour.
Lucky Patcher Dalvik-cache
I am getting out of space msg when using Lucky Patcher.....apk will be patched on boot......it says to clear dalvik cache to save space.....is this a good idea(will I loose any data from game etc?) or this a issue with lucky patcher?
Clearing Dalvik
Feanor88 said:
When you reboot, Dalvik cache and Cache are re-created. So no space saved this way.
Click to expand...
Click to collapse
Um, that would involve the re- "optimization" process at each boot. Depending on the number of apps you have installed, this process can take an hour.
Simply put, the Dalvik cache is where a virtual machine program (like VMware Player, Workstation or Fusion or MSVM) called "Dalvik" stores information the applications on your device request it to. This storage is for the purpose of making app load times shorter, but because it's all low-level stuff, it has to be loaded prior to the AndroidOS frontend...Fortunately, this cache only needs to be rebuilt when a flag has been set indicating the need, which is set whenever the cache is cleared. Note the distinction between "loading" and "rebuilding" this cache. "Load" is synonymous with "read" and "rebuild" means "write." So time-wise it is the distinction in effort between reading a book and writing one.
Typically I only clear it for troubleshooting reasons; if something is not working. The latest Cyanogenmod has a major problem where the desktop data is liable to randomly corrupt.
Typically, the only solution is a Dalvik wipe in CM or whatever. If you have recently installed a large number of apps(over twenty)then it might be best to clear the cache via recovery at the next cold boot, especially if your device does weird stuff like getting hot, discharging while plugged in to the OEM charger, widgets crash spontaneously, wallpapers are replaced by defaults, etc....Some of these symptoms can also indicate a virus or malware infection,(especially on custom ROMs or rooted devices) so diagnosis is differential.
But essentially there is no harm in re-building the Dalvik cache, other than the time taken to do so.
Koptanov said:
Yes sir it's only the dalvik cache, both ways this ROM was pretty heavy and i'm not satisfied with the reboot every 2 or 3 hours of use, i will install xperia ultimate HD ROM, they say it's pretty stable and has no problems, and it has the sound enhancements i needed in the Jellybean cooked ROM
thanks for your reply
Click to expand...
Click to collapse
CM has this new MAJOR stability issue, it seems. The random crashes and reboots will soon combine(if they haven't already)with the deletion of your desktop customizations and your widgets will begin vanishing forever. Not even a full wipe and rebuild will bring them back.
Been using AOKP on Nexus 7 2013 for a month now. It is based on CM, but it is way more stable.....haven't needed to re-boot in two weeks! Uptime, baby!
UPDATE 04/05/2014: Been running without rebooting for over a month, now. AOKP is definitely WAY more stable than any other ROM I've used.
Dalvik explained
Saqib Nazm said:
As far as I know, when a rom boots up for the first time Dalvik goes through each & every apk's & extract the Dex & put it in the cache. So probably it is a location of all apks. If dalvik cache is not wiped after a new rom is installed,dalvik cache will skip because it founds the dexed cache files attach to the directory. The result is "Force close" issues.
So wiping dalvik cache can be done without any problem many times within the same rom & that's why is shows "optiming apps" after a dalvik cache wipe.
Click to expand...
Click to collapse
There is a full explanation of the dalvik cache on wikipedia.
The wiki entry fully explains dalvik cache and the integral part it plays in your android system. In very simple terms, it is a cache that allows the system to talk to the exe of a program without the need to load the cache on each and every start. The dalvik is is loaded once, and then never again (unless you wipe the dalvik cache, in which case, it is rebuilt upon reboot). There is no affect on any given program when the dalvik cache is wiped, other than starting slower the first time it is started after the wipe.
Related (I think) - Samsung Galaxy S5 running CM 12.1 latest nightly (6-14). I started on CM 12.0 nightlies in March or April and transitioned to 12.1 within a day or two acter it showed up. That was a relatively noticeable transition requiring new gapps and a factory reset as I recall. I read somewhere that wiping cache and dalvik cache was unnecessary between one 12.0 nightly to another and between one 12.1 nightly to another, so I typically have not performed the cache and dalvik wipe during nightly upgrades, of which I've probably done 30 or 40 since I started on 12.0. After each nightly update flash, when I ask TWRP to reboot the system, without wipes, all my 160 or so apps are optimized, taking some time, before the noot is compete. This morning out of curiosity, after the nee ROM was flashed, I chose the option in TWRP to wipe the cache and dalvik cache before I askefasked TWRP to reboot the system. The wipe process took at least as long to complete as a typical optimization, and when I rebooted, I still got the lengthy optimization. So I'm tbinking either there's no relationship berween app optimization and wiping the caches, or CM and/or TWRP automatically wipes the caches whether I do or not.
---------- Post added at 12:58 PM ---------- Previous post was at 12:54 PM ----------
Please forgive typos in my previous post - SwiftKey or something is making proofreading and editing difficult today.
Not the exact answer, but may interests u.
Koptanov said:
Hi Geeks
i have an Xperia Arc S modded with Cyanogenmod JellyBean 4.1.2 Cooked ROM
i had alot of memory issues as applications keep closing whenever system runs out of memory, it is always obvious in the DSP application with the walkman in addition to visualizations inside the walkman
AMR
Click to expand...
Click to collapse
Hi, I do not have the exact answer. But I wanted to share my own observation. When I wipe dalvik caches through CWM recovery, I find my phone taking a long time to finish booting every time. Sometimes I thought it would not boot up, I removed the battery and tried to swith on and my phone boots up. I do not know why it happens, may be I had installed a large no of apps.
I've got Nexus 5 with bootloader unlocked , after few weeks security patch arrived and after the phone switched off and showed error symbol and when I entered recovery mode it showed that error in system/bin.sh files need some help here

Upgrade ROM "SGT7+CM10+Cherry Picks,By meghd00t"?

hi,
this ROM works very nice for me, thanks all the deveopers!
i have few questions:
(1) since this ROM has OTA updater (it seems, from the changelog), next time when the new version is realeased, can i just update the ROM via OTA updater?
(2) i dont really understand what “Wipe cache/dalvik” and “Wipe data / factory reset” really do. my guess is that “Wipe data / factory reset” repartitions the internal flash memory of the original memory, so we can use all the memory for our purpose. (not like original Nook Tablet, in which they dedicate only 1GB for personal usage)
if i understand all these correctly, this means next time if i flash the new ROM and want to keep the old data, i should not do "Wipe data / factory reset", but only need to do "Wipe cache/dalvik"? is this correct?
thanks so much,
Jun
junkoi said:
hi,
this ROM works very nice for me, thanks all the deveopers!
i have few questions:
(1) since this ROM has OTA updater (it seems, from the changelog), next time when the new version is realeased, can i just update the ROM via OTA updater?
(2) i dont really understand what “Wipe cache/dalvik” and “Wipe data / factory reset” really do. my guess is that “Wipe data / factory reset” repartitions the internal flash memory of the original memory, so we can use all the memory for our purpose. (not like original Nook Tablet, in which they dedicate only 1GB for personal usage)
if i understand all these correctly, this means next time if i flash the new ROM and want to keep the old data, i should not do "Wipe data / factory reset", but only need to do "Wipe cache/dalvik"? is this correct?
thanks so much,
Jun
Click to expand...
Click to collapse
Wipe data/factory reset is an option in CWM Recovery. Really all it does (from the screen messages) is format both /data and /cache.
Assuming you have CWM Recovery (though I imagine that there are similar entries in TWRP, I've just never used it), to wipe both of the caches you will first need to go to the entry "Wipe Cache Partition", which I believe is directly below Wipe Data/Factory Reset. Do that 3x (that's always been the recommendation, anyway) then go to Advanced and click on Wipe Dalvik Cache (again, 3x).
Again, assuming CWM Recovery, when you're in the recovery Vol Up/Down goes up and down in the list, the 'n' key is for Enter, and the Pwr button goes back.
I don't know about the OTA Updater. I always download and install ROMs (on both my phone and my NT) via Recovery.
Since this is a CM10 based rom you probably don't want to do the ota updater since that is a Cyanogenmod feature. This rom is optimized for the Nook from the CM10 Source I would presume. I personally tried the ota uldater since i get the notifications all the time but i get an error message something like "can't verify the source with a string of numbers". Stick to the recovery based flash installation.
Sent from my SPH-L710 using xda app-developers app
---------- Post added at 10:48 AM ---------- Previous post was at 10:10 AM ----------
I agree with liquidzoo that you should probably do the wipe cache, wipe dalvik cache and factory reset 3times seems like overkill but you can never be too safe. Also i use twrp recovery and click the system button and wipe system a few times as well.
Sent from my SPH-L710 using xda app-developers app
kobhomye said:
I agree with liquidzoo that you should probably do the wipe cache, wipe dalvik cache and factory reset 3times seems like overkill but you can never be too safe. Also i use twrp recovery and click the system button and wipe system a few times as well.
Sent from my SPH-L710 using xda app-developers app
Click to expand...
Click to collapse
I wipe /system 3x as well (under Mounts in CWM Recovery) when I'm installing a new ROM.
liquidzoo said:
I wipe /system 3x as well (under Mounts in CWM Recovery) when I'm installing a new ROM.
Click to expand...
Click to collapse
I'm not picking on you personally, but deleting and/or wiping partitions (in the case of /system) or directories (dalvik-cache) three times as opposed to once is completely unnecessary. You'll gain nothing by running the command three times over running it once, assuming you received no errors the first time.
When wiping the dalvik cache, both CM recovery and TWRP perform an "rm -rf /data/dalvik-cache" command using the shell. It's not Windows, and is unlikely to fail when passed the "-f (force)" option along with the "-r (recursive)" option.
In the case of wiping the /system partition, again both CM and TWRP write out zeros to clear the data on the partition. I would be suprised if CWM acted differently from CM and TWRP when wiping dalvik-cache and /system.
The only reason I bothered to look into what these commands actually do is to prevent a user from thinking there's a corellation between a failure to wipe 3x versus a problem they're having. If a 3x wipe "fixes" something for you, whatever the problem was, it's very unlikely that the second or third wipe was what fixed it but instead it was more likely a result of a clean install of the ROM.
References from source:
TWRP Wipe Dalvik - https://github.com/TeamWin/Team-Win...548de276b62c0e9af8661e/extra-functions.c#L986
TWRP Wipe/Format System - https://github.com/TeamWin/Team-Win...8de276b62c0e9af8661e/mtdutils/mtdutils.c#L498
CM Wipe Dalvik - https://github.com/CyanogenMod/andr...aa7ff3d06d5dd115b16c/extendedcommands.c#L1292
CM Wipe/Format System - https://github.com/CyanogenMod/andr...aa7ff3d06d5dd115b16c/mtdutils/mtdutils.c#L498
Have fun modding!
No worries, it's just something I've always done as it's been recommended to me in the past (there are some ROM developers that recommend 5x, actually). I'm not saying that 3x over 1x is any better, but I've never had issues. YMMV, but it doesn't take much more time and I like being thorough.
liquidzoo said:
Wipe data/factory reset is an option in CWM Recovery. Really all it does (from the screen messages) is format both /data and /cache.
Assuming you have CWM Recovery (though I imagine that there are similar entries in TWRP, I've just never used it), to wipe both of the caches you will first need to go to the entry "Wipe Cache Partition", which I believe is directly below Wipe Data/Factory Reset. Do that 3x (that's always been the recommendation, anyway) then go to Advanced and click on Wipe Dalvik Cache (again, 3x).
Click to expand...
Click to collapse
sorry, but can you confirm that when i upgrade to the new ROM (from the same author), it is really necessary to Wipe cache &Dalvik cache?
i am confused because somebody told me that i can just flash the ROM by installing the ZIP file (containing the ROM), and reboot the Nook without having to wipe or clean anything.
thanks,
JK
Flashing a ROM
junkoi said:
sorry, but can you confirm that when i upgrade to the new ROM (from the same author), it is really necessary to Wipe cache &Dalvik cache?
i am confused because somebody told me that i can just flash the ROM by installing the ZIP file (containing the ROM), and reboot the Nook without having to wipe or clean anything.
thanks,
JK
Click to expand...
Click to collapse
I don't know if I am doing it right or wrong but I have flashed numerous ROMs and lately have flashed every version of SGT7+CM10+Cherry Picks,By meghd00t. from 24/09 thru my current installation of 08/10 with only one glitch and that was when I flashed enhancements v2 on top of v1.
I have never had any other issues with the above mentioned ROMs except when I flashed 04/10 with enhancement v2. I didn't have the tablet option.
The way I do it is as follows:
1. format /system
2. format /data
3. Flash ROM
4. Flash CWM emmc
5. Flash GAPPs
6. Reset Factory/format data
7. Remove CWM SD card put in data SD Card with Flash Player (no longer avail on Google Play)
8. Boot from CWM menu
Takes awhile to boot this first time. When booted up I bypass the setup screens.
9. Manually set up wireless (need to access auth web site at work and need wireless to be working to accomplish that)
10. Browse to a web site and get redirected to auth page.
11. Auth
12. Set up Google account and other settings, especially under Security <Install from other locations>
13. Download apps I want from Google.
At this first boot SD card is not mounted.
14. Shut down and do a cold boot.
Now I can see SD Card.
15. Install Flash Player from External SD Card.
16. Install Crackle from Play Store.
Now I check Pandora for Audio, Crackle for Video, other apps I use, utilities, keyboards, launchers, games, etc.
So far since Version 24/09 everything has worked for me with the two exceptions above, tablet mode with 04/10 with enhancement v2 and when I flashed enhancement v2 over enhancement v1.
I am now running 08/10 and am very happy with the performance, battery drain is more than CM7 but that is to be expected from a fairly new ROM but not so bad that it is unacceptable, to me at least.
I have never had a black screen or arbitrary reboot (knock on wood). However I do turn my tablet off when I am finished using it, so don't know about deep sleep. I'm using OnDemand, and three launchers without one being the default....Apex, Nova and Trebucket.
All I can say is these developers really ROCK, way to go guys!
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MojoGB said:
The way I do it is as follows:
1. format /system
2. format /data
3. Flash ROM
4. Flash CWM emmc
5. Flash GAPPs
6. Reset Factory/format data
7. Remove CWM SD card put in data SD Card with Flash Player (no longer avail on Google Play)
8. Boot from CWM menu
Click to expand...
Click to collapse
You don't need to re-flash CWM every time you flash a ROM. Also, it doesn't make sense to me why you would do a factory reset/format after flashing the new ROM, I would think it would be done prior to flashing the ROM but maybe it doesn't make a difference, I don't know.
I've got TWRP installed to the emmc so I just download the new ROM to the SD with GooManager, reboot into recovery, do a backup, factory reset, flash new ROM & GApps and reboot. Only takes a few minutes.
Reflash ROM
LifeWOutMilk said:
You don't need to re-flash CWM every time you flash a ROM. Also, it doesn't make sense to me why you would do a factory reset/format after flashing the new ROM, I would think it would be done prior to flashing the ROM but maybe it doesn't make a difference, I don't know.
I've got TWRP installed to the emmc so I just download the new ROM to the SD with GooManager, reboot into recovery, do a backup, factory reset, flash new ROM & GApps and reboot. Only takes a few minutes.
Click to expand...
Click to collapse
Tried it as you mentioned, doing a factory reset before flashing the ROM and got a black screen and wouldn't boot. May have been a fluke but the way I mentioned above gives me a good image and alway boots. Don't know why, but if it works for me, I will continue to do it this way as long as it works for me. I have flashed numerous other ROMs the same way with good results each time.
junkoi said:
sorry, but can you confirm that when i upgrade to the new ROM (from the same author), it is really necessary to Wipe cache &Dalvik cache?
i am confused because somebody told me that i can just flash the ROM by installing the ZIP file (containing the ROM), and reboot the Nook without having to wipe or clean anything.
thanks,
JK
Click to expand...
Click to collapse
For an update, yes it is recommended to clear both caches. To be clear, this is only for an update. If it is a new ROM, or if the author recommends it, you should also wipe /data and /system first.
You can just flash without clearing them, but you might run into unexpected issues, so it's not recommended.
MojoGB said:
Tried it as you mentioned, doing a factory reset before flashing the ROM and got a black screen and wouldn't boot. May have been a fluke but the way I mentioned above gives me a good image and alway boots. Don't know why, but if it works for me, I will continue to do it this way as long as it works for me. I have flashed numerous other ROMs the same way with good results each time.
Click to expand...
Click to collapse
I get a black screen for a while on first boot too, but it only last a couple minutes at the most and if you shine a bright light at the screen you can see the CM logo spinning. Are you sure it was hung?
Sent from my Barnes & Noble Nook Tablet using xda premium
When you clear the Dalvik cache, it clears out data stored in your applications. When you turn on your Nook after clearing the Dalvik, the first thing it does is it rebuilds the Dalvik cache, that's why it seemed like it hung on startup. I believe the long black screen in the beginning is when it rebuilds Dalvik for core Android apps and then when it says "Optimizing Apps", that's for the rest of your applications. The more apps you have, the longer it will take to build the Dalvik. No need to freak out, just a little patience is all you need. Correct me if I'm wrong, however, as I'm still pretty much a noob at this... :laugh:
Flash a Rom
topdawg7793 said:
When you clear the Dalvik cache, it cleares out data stored in your applications. When you turn on your Nook after clearing the Dalvik, the first thing it does is it rebuilds the Dalvik cache, that's why it seemed like it hung on startup. I believe the long black screen in the beginning is when it rebuilds dalvik for core Android apps and then when it says "Optimizing Apps", that's for the rest of your applications. The more apps you have, the longer it will take to build the dalvik. No need to freak out, just a little patience is all you need. Correct me if I'm wrong, however, as I'm still pretty much a noob at this... :laugh:
Click to expand...
Click to collapse
Well fhe screen was black, no light at all and I waited for over five minutes for the Flash Screen to come up and it never did. Yes I know when you are waiting time drags. But due to the ROMS always taking awhile to boot up the first time I actually pay attention to how long it takes. No more then 2 minutes in my experience. I had to hold the power button in for a long time until it finally booted in B&N Recovery. Used my sequence mentioned in earlier post to flash the ROM again and everything worked as it should, GREAT. The number of APPs shouldn't be an issue as these ROMS only have the very basic apps.
I have read this forum and see the various and asundry errors some are getting, so far I have never gotten a major error, except for when I forgot to do the Wipe Data/Factory Reset after flashing.
I also got the "No Tablet Mode Option" with 04/10 with enhancement v2.
But I consider these minor issues and currently am running 08/10 with no issues, works smoother then any version of Microsoft Windows I have dealt with.
These developers are exceptional.
MojoGB said:
I don't know if I am doing it right or wrong but I have flashed numerous ROMs and lately have flashed every version of SGT7+CM10+Cherry Picks,By meghd00t. from 24/09 thru my current installation of 08/10 with only one glitch and that was when I flashed enhancements v2 on top of v1.
I have never had any other issues with the above mentioned ROMs except when I flashed 04/10 with enhancement v2. I didn't have the tablet option.
The way I do it is as follows:
1. format /system
2. format /data
3. Flash ROM
4. Flash CWM emmc
5. Flash GAPPs
6. Reset Factory/format data
7. Remove CWM SD card put in data SD Card with Flash Player (no longer avail on Google Play)
8. Boot from CWM menu
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Click to expand...
Click to collapse
oh, so you always reset factory every time you upgrade the ROM? that way will delete all the old data/apps you installed, so you need to install all the apps again?
this is my concern, because i dont want to reinstall apps, or lose my data. so i think i just need flash the new ROM, then Wipe cache/Dalvik cache, and hopefully all the old apps and data are still intact.
thanks.
MojoGB said:
I don't know if I am doing it right or wrong but I have flashed numerous ROMs and lately have flashed every version of SGT7+CM10+Cherry Picks,By meghd00t. from 24/09 thru my current installation of 08/10 with only one glitch and that was when I flashed enhancements v2 on top of v1.
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Click to expand...
Click to collapse
i have some questions on the "Enhancements":
(1) the correct way to install them is to flash version 1 first, then immediately flash version 2 right after version 1 (without having to reboot first)?
(2) i am not sure what i will get with this "enhancements". they will make video/audio playing more smoothly? is the quality improvement really noticable? anything else, like they make the battery last longer, for example?
thanks,
Jun
If you're running 08/10, the enhancements are not needed. That's my understanding at least. I had problems with V2 so I decided to not install them while on 04/10.
Sent from my Barnes & Noble Nook Tablet using xda premium
Flash Rom
junkoi said:
i have some questions on the "Enhancements":
(1) the correct way to install them is to flash version 1 first, then immediately flash version 2 right after version 1 (without having to reboot first)?
(2) i am not sure what i will get with this "enhancements". they will make video/audio playing more smoothly? is the quality improvement really noticable? anything else, like they make the battery last longer, for example?
thanks,
Jun
Click to expand...
Click to collapse
If you flash enhancement v2 on top of version 1 you will have problems, UI will stop. If you only flash v2 you will not have the Tablet Mode Option. So my understanding is that you can use either v1 or v2 but not both.
ROM 08/10 does not need either enhancement as indicated by the developer. ROM 08/10 works great by itself is my experience.
If I'm installing a ROM, backup the existing ROM and wipe everything.
If I'm installing a .zip package like GApps or an enhancement, backup the existing ROM, wipe Data/Dalvik.
Folks, these are development ROMS. Thar be bugs in thet thar code. It's going to take you longer than the time you think you're going to save by doing a dirty flash, and then having to restore the thing to stock (worse case) only to start all over.
Don't ask how I know.
wellersl said:
If I'm installing a ROM, backup the existing ROM and wipe everything.
Click to expand...
Click to collapse
so it is possible to back up the existing data/apps, then restore them back after the new ROM is flashed? could you please confirm this?
if so, how & what is the right steps to do the backup? can we still use CWM, or use ROM Manager, or other tools?
thanks

[Q] ROM's problem, bugged phone? Please help

Why every time when i install ANY rom to my galaxy s2 after 2, 3 weeks this rom is crashed? It's start crashing with closing apps "application must be stopped". How to fix it? It's the same in every ROM which i install, it makes me crazy right now...
Still no reply?...
Wipe cache and dalvik cache in Recovery.
Sent from my Galaxy S2 GT i9100
I do it always and rom's are still going to be bugged for 7-14 days.
I think I saw you in Paranoid Rom thread mate. Did you come from GB? Just format everything and start again and report back. Format external and usb storage. Wipe data/factory reset. Wipe cache and dalvik and stats once or twice if you wish. Remove crap from init.d or voltage settings just to be sure. Then once you are happy flash rom. Follow instructions - fix permissions etc, etc..See how you go mate.
If it is a specific ROM you are having a problem with maybe post in that ROM's thread to get quicker replies.
EDIT: Also don't restore settings - start from scratch. Don't always restore App+data with Titanium just app only for now.
Before i had problems with every ROM after few days. Yes i come from GB without formatting storage. Thanks for professional response. That's what i did actually:
1. Format external and internal storage.
2. Wipe cache, Wipe data & Wipe dalvik cache.
3. Flash Paranoid 2.22 ROM.
4. Again point 2.
5. Titanium backup just necessary apps.
We will see how long everything will be fine.
PS. what about fix permission? When to do it? And how to remove this "crap" from init.d?
Point 4: Not sure about point 4 - just the dalvik cache and then select fix permissions here. I wouldn't wipe cache and data/factory reset all over again at point 4.
Point 5: Let ROM boot (will take a few minutes)
Point 6: Run an app or two then reboot to make sure..
Point 7: Begin restoring apps or play with governors etc and whatever you like
The "crap" I meant was if you had any additional scripts or tweaks that are in init.d folder during startup. So they don't interfere on first startup. Never tried a kernel cleaning script/cwm flashable file coz there have been some useless ones in the past but give that a try (someone else may be able to comment here).
Remove voltage settings if you were using voltage control app in GB. Reset to default in Extweaks if you were just using this. (Not sure if all this is necessary because I do this prior to formatting or factory resets - someone more knowledgeable can help here).

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