Develop Bugs

What does wiping delvik-cache actually do?

Just wondering what wiping delvik-cache actually did... I know the 'duh it wipes your delvik cache' answer is right on the tip of your tongue but what I mean is, what do you lose from wiping it? What's actually stored in there? Anything that would break from wiping it?

itpromike said:
Just wondering what wiping delvik-cache actually did... I know the 'duh it wipes your delvik cache' answer is right on the tip of your tongue but what I mean is, what do you lose from wiping it? What's actually stored in there? Anything that would break from wiping it?
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This would have been more appropriate in the Q&A section... however...
As I understand it, the dalvik cache stores optimized versions of your application dex files. The dex file is a dalvik executable file and is filled with dalvik bytecode. It is very similar to java in that regard. Most of the stock apk's located in your phone's rom have odex files which are optimized dex files not needed to be stored in the cache. I am unsure as to wether or not they actually are.
Clearing it shouldn't be a problem, you may notice a slight startup lag the next time you open an application after wiping the cache as it repopulates the dex files. There is also a possibility of the cache getting filled with left over garbage if you install/uninstall apps frequently. However I can't back that up with any personal experience or research.
Anyone, feel free to correct me if I have given any false information.

obelisk79 said:
This would have been more appropriate in the Q&A section... however...
As I understand it, the dalvik cache stores optimized versions of your application dex files. The dex file is a dalvik executable file and is filled with dalvik bytecode. It is very similar to java in that regard. Most of the stock apk's located in your phone's rom have odex files which are optimized dex files not needed to be stored in the cache. I am unsure as to wether or not they actually are.
Clearing it shouldn't be a problem, you may notice a slight startup lag the next time you open an application after wiping the cache as it repopulates the dex files. There is also a possibility of the cache getting filled with left over garbage if you install/uninstall apps frequently. However I can't back that up with any personal experience or research.
Anyone, feel free to correct me if I have given any false information.
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That's perfectly correct.
For any app that's not accompanied by an odex, an optimized extracted copy of it's bytecode is stored in dalvik-cache.
I've yet to see if uninstalling an app also erases it's respective dalvik-cache or not, checking for that hadn't crossed my mind, but I don't see why it shouldn't.
The real reason you're supposed to wipe your dalvik-cache is because sometimes between builds you get two versions of an app that have the same namespace. The VM will try to use the already stored cached bytecode, but there's a chance that it might be incompatible and it will cause a force-close, in that case, it's best to let the vm build new optimized bytecode for the app, but, as obelisk pointed out, it's going to take a while to re-build the dalvik-cache if you erase it all (the more apps with a .odex you have, the less time it takes).
I think in 2.0 there's now a routine where the dalvik-cache is checked against the app .dex for compatibility, I might be wrong though, but I think I've seen it erase old caches and create new ones. It might be something else entirely though.

I know I'm off topic but your sig made me chuckle.

[Q] Can I free up System ROM memory?

Okay so in Titanium Backup my free System ROM memory is 229MB. SD Card Maid says 211MB free. Im not sure why they both have different values but, can I make any of these unused MB converted to usable system space for more apps? I've tried making some apps system apps through Titanium Backup and that takes more ROM memory and makes the used internal memory less, but that just makes the apps unusable. Im using CM7 Nightly and CWM Recovery. Thanks for the help.

Well I probably found an answer in this thread http://forum.xda-developers.com/showthread.php?t=855424 but if anybody has another suggestion .....

Sure you can. I recommend using Titanium Backup to uninstall system apps. Be sure to make a full backup using whichever recovery you currently are using jiust encase you delete something important. I removed apps related to live wallpapers, friend streams, twitter etc. Features I don't use. Hope this helps.

I forgot to ask. Do you have a SD-EXT partition set up? May want to look into that.

Removing system apps doesn't free up storage for installing user apps. You can manually move apps into the system partition if you want, but you have to redo that after that app gets upgraded. The other option is to play with MTD partition size as mentioned in the thread you found.

You can't flash the apps to system/data?

sednafx said:
You can't flash the apps to system/data?
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/system/app is where they'd go. You don't necessarily need to flash them there, you can use Titanium or a root-capable file explorer to move them. Some apps need some extra steps to work with their native libraries though. In addition the problem I mentioned of updates going back to /data/app instead of updating in the system partition, you also have to keep track of what you've moved in and do it again if you flash an updated ROM (without wiping).

bkrodgers said:
/system/app is where they'd go. You don't necessarily need to flash them there, you can use Titanium or a root-capable file explorer to move them. Some apps need some extra steps to work with their native libraries though. In addition the problem I mentioned of updates going back to /data/app instead of updating in the system partition, you also have to keep track of what you've moved in and do it again if you flash an updated ROM (without wiping).
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You are correct. Good points.

I don't have an SD EXT but I'll look into that. The link I posted helped alot. Thanks for all your help guys.

hi guys .. i don't know if this is a dumb question .. i am not expert at flashing custom roms .. in my titatinum backup info .. my system rom got 200+mb free and now i want to flash a custom rom but its size is 300mb+ ?? should i still continue or is there anything else to solve this??

[Q] How to get my apps/games back from my second partition after factory reset?

I have been using Link2sd for a while now and just wanted to know is there a way to get all my apps/games back after flashing a new rom or after factory resetting my phone.
There should be coz all the apps and there data, .dex files and lib files etc, are already there on the second partition. Isn't there anything I can do. I just dont want to reinstall everything again.

if you didn't wipe/format the 2nd partition, all the files will still be there, just select "relink library files"

leodasal2 said:
if you didn't wipe/format the 2nd partition, all the files will still be there, just select "relink library files"
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I did tried "Relink lib files" option but still nothing.

Wipe your partition and reinstall.

I think link2sd just move app, lib, and dalvik-cache if i'm not wrong so data still in internal and will gone after flashing.
-Just Farmer and Newbie Android-

raolemo said:
Wipe your partition and reinstall.
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Yeah thats exactly what I was trying to avoid
savie said:
I think link2sd just move app, lib, and dalvik-cache if i'm not wrong so data still in internal and will gone after flashing
-Just Farmer and Newbie Android-
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Well I guess I can't. Can it be done using other apps like a2sd, data-2d etc.

wasim0 said:
Yeah thats exactly what I was trying to avoid
Well I guess I can't. Can it be done using other apps like a2sd, data-2d etc.
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Yup you can. But for a2sd must move data app to sd-card, usually use titaniumbackup.
-Just Farmer and Newbie Android-

Low system memory bug

Hi,
The problem is, that I cant install apps that are over 6mb. Sometimes updates just remove apps from my phone, just saying "not enough space". The best part is, that I have ~130MB on /system, and 1,5GB on /sdcard! It happens both on stock-based roms and FXP 133 (CM9). I just have no clue what to do.
Wiped dalvik cache, cache, formatted data and system, it just happens no matter what. After moving all apps to SD problem persists. What am I missing?
Xperia arc, FXP 133 anzu, with included kernel
Forgot to add: It's a fresh installation. Sometimes larger applications install properly. I had problems with Titanium Backup and Sygic.

Not sure but if you're moving apps etc. to your SD card you might need to clear up space or buy another SD card (i recommend 12 -16gb SD card)
If its stored in internal memory you might need to do the same and clear up space

Have you tried using another sd card just to make sure whether the problem is with your existing sd card or device?
Sent from my LT15i using xda app-developers app

Sandro8771 said:
Have you tried using another sd card just to make sure whether the problem is with your existing sd card or device?
Sent from my LT15i using xda app-developers app
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It has nothing to do with sd-card, can u both read? Should I provide logcat?
EDIT: Sorry, I meant nothing offensive, I'm just too direct sometimes.
What else is there left to wipe, when /system, /data, /cache and dalvik cache has been purged? Apps simply download, install and then Google play gives notification about lack of disk space. It happens even, when I install apk's using ES File Explorer. Why can I install games larger than 15MB (no sd data, so it lands entirely in phone memory), and can't install 6MB Sygic? APK file is NOT corrupted, it works on my other phone. Market version is no good as well...

Same problem with me too, i tried to install Google Now (http://forum.xda-developers.com/showthread.php?t=1818189) and it refuses to copy the files in the /system with the error "Not enough memory".
It was fine till i used Pureness ROM, but now i am on Jelly Sandwich.

When you install an app, there is two files, the apk and the corresponding odex file (same name than the apk, suffix is '.odex'). Sometime, when you play with restore, moving apps in system, odex them or changing rom without cleanup, the ".odex" file remains. Search for corresponding odex file in /system/app or /data/app and delete it.

When you save apps to internal they go into data/app not system /apps
check what space you have if needed save some gspps from internal to system by using app called links2sd free from play store.
Try cleaning the dalvik cache this is not the same as deleting the mentioned app can do this.
titanium backup can help with moving to system and cleaning to dalvik.
Also look in vendor/app there may be some issues there.
Sent from my LT15i using xda premium

zolaisugly said:
When you save apps to internal they go into data/app not system /apps
check what space you have if needed save some gspps from internal to system by using app called links2sd free from play store.
Try cleaning the dalvik cache this is not the same as deleting the mentioned app can do this.
titanium backup can help with moving to system and cleaning to dalvik.
Also look in vendor/app there may be some issues there.
Sent from my LT15i using xda premium
Click to expand...
Click to collapse
vendor/app holds one small file, it has sth to do with ringtones, so it's not that.
Before switching roms I always make a proper cleanup.
There is sth interesting about system app manager though, it shows that "19..." of internal storage is used and "183 MB" is free. Why are there three dots instead of MB, and why is it just 19? It looks like the dots replaced sth that doesn't fit inside of the text field (190MB?).
Why does it happen after cleaning everything, on fresh, "Out-of-the-Box" rom? I could understand it on Ice Bean (it started on that rom), it was 200mb+ stock-based rom, but FXP is just ~130mb! There should be plenty of space for app data.
EDIT: Wow, thats even more odd, I've just managed to install all the apps I couldn't! Like the problem was never there. It's weird and I still want to know what the hell was that, and make sure it won't happen again, as I have no time for X Files kind of things.
Thanks for feedback, so far.

Out Of Space

I'm starting to get an "Out of space" message when installing apps. It happened a couple of times from Market, and now its happening when I side load apps. From all indications I have plenty of space (11 GB free). I've cleaned cache, force stopped Market and Google Frameworks clearing their cache, rebooted into recovery and wiped cache, wiped dalvic, and fixed permissions. Its getting to the point that Market updates are hit and miss as to whether they will install. Is this a RAM issue? What can I do next? Running JR6 w/ Franco #264. Thanks.

v12xke said:
I'm starting to get an "Out of space" message when installing apps. It happened a couple of times from Market, and now its happening when I side load apps. From all indications I have plenty of space (11 GB free). I've cleaned cache, force stopped Market and Google Frameworks clearing their cache, rebooted into recovery and wiped cache, wiped dalvic, and fixed permissions. Its getting to the point that Market updates are hit and miss as to whether they will install. Is this a RAM issue? What can I do next? Running JR6 w/ Franco #264. Thanks.
Click to expand...
Click to collapse
Check if you have a .odex file in /data/data (from Titanium Backup)
if you do, delete it. That caused some issues for me.
Sent from my Galaxy Nexus using xda premium

Thanks for the suggestion. I do use TiBu but seaching with Root Explorer, I did not have any odex files in that folder. I do have less than 20 odex files total, most located in the /data/app/ folder, ranging in size from a few kB up to 3 MB. Are they safe to delete? Not even sure if I go back to an earlier nandroid, I may still end up with the same problem. Its not crippling at the moment, so I'll hang on for a while to see if there are any other ideas I can try before wiping and reloading.
EDIT:
OK, one of the odex files in the /data/app folder was from the program I could not install. I deleted it, and was then able to install the program. WTH? I tested deleting one of the other odex files (to see if I could just delete them all) and the program would just FC immediately. I guess the only odex files that are safe to delete are of apps you no longer use. Not sure why the odex file kept me from installing the program, but at least it is fixed. Thanks to Lesicnik1 for putting me on the right track. Cheers.