Database Users

What is Dalvik Cache?

What is it? Thanks

http://lmgtfy.com/?q=dalvik+cache

Ok, I searched and found it. But I'm running into a lil problem. I did the apps2sd thing on my 2gig sd card and now in settings, its showing 1gb for the sd card and 1gb total space for the internal storage(which isn't right because the phone doesn't come with that much storage, right?).
What am I doing wrong?

Even after searching on Google it seems that the purpose of Dalvik Cache is very convoluted. From what little I understand it's the location where application data stored by the OS... but I could be wrong.

Simple explanation:
When Android starts up, the DalvikVM looks thru all of your applications (.apk files) and frameworks, and builds a tree of dependencies. It uses this dependency tree to optimize the bytecode for every application and stores it in the Dalvik cache. The applications are then run using the optimized bytecode. This is why when you install a new ROM, sometimes it takes a very long time to boot for the first time. Any time an application (or framework library) changes, it's reoptimized and the cache is updated.

Cyanogen- Thanks! By the way, great job on the rom. I'm running it right now.
So can you tell me why people want to move it to their sd? (By doing the apps2sd, did I already do this?)
Thanks again.

legaleye2005 said:
Cyanogen- Thanks! By the way, great job on the rom. I'm running it right now.
So can you tell me why people want to move it to their sd? (By doing the apps2sd, did I already do this?)
Thanks again.
Click to expand...
Click to collapse
To save memory, of course. And you probably haven't moved your dalvik cache to your SD Card yet.

Ironic
alapapa said:
http://lmgtfy.com/?q=dalvik+cache
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This post is the #2 link in that search... Just found that kind of ironic.

I'm sorry I came off as snide and dismissive -- i guess i was...
I really should have just posted this:
http://en.wikipedia.org/wiki/Dalvik_virtual_machine

If you want to know about the guts of whats going on with the "dalvik cache", try here:
http://android.git.kernel.org/?p=platform/dalvik.git;a=blob_plain;f=docs/dexopt.html;hb=HEAD

As for this thread it will be moved to GENERAL, since this has no bearing on developement of the G1

legaleye2005 said:
Ok, I searched and found it. But I'm running into a lil problem. I did the apps2sd thing on my 2gig sd card and now in settings, its showing 1gb for the sd card and 1gb total space for the internal storage(which isn't right because the phone doesn't come with that much storage, right?).
What am I doing wrong?
Click to expand...
Click to collapse
A2sd "tricks" your phone into thinking that the partition on your sdcard is part of the phones internal memory. Some time report the internal memory correctly others do not its a bug of sorts. Don't worry you did nothing wrong

ubernicholi said:
A2sd "tricks" your phone into thinking that the partition on your sdcard is part of the phones internal memory. Some time report the internal memory correctly others do not its a bug of sorts. Don't worry you did nothing wrong
Click to expand...
Click to collapse
I believe that is my issue with the new 8GB class 6 card and how my G1 is now slower than the Tandy 1000 I had, long ago. Performance at max CPU speed is now 60-75% SLOWER than when I had all apps on "internal storage" with 7MB free. My ext2 partition on the 8G card is around 830M. I purchased the "appstosd2" from the market, but I'm guessing the s-l-o-w performance is because I have NOT (yet) put the Dalvik-cache on the card's ext2 partition. After reading: http://android.git.kernel.org/?p=platform/dalvik.git;a=blob_plain;f=docs/dexopt.html;hb=HEAD
...it seems that's most likely the "slowness issue". Like launching an app where parts of it have to come from a different hard drive.
I'll try moving the Dalvik-cache to the sd with the apps, but since I only made an 830M ext2 partition, I'd like to view the SD card within Linux Live CD. Perhaps there I could "resize" it to 1200-1400M. Then again, I'd like to keep the apps that came with the device "Market, Browser, Maps etc" within the device's internal memory, while installing pHaT apps to the ext2 partition, such as iMAP weather, aFile, pacman (with flickering screen on 1.5 builds ö) and really large apps that many ppl UN-install and report "I need more space on my phone".
I'm not too new of a noob, however I am a "super noob" when it comes to Linux. I setup my laptop to dual boot Win XP or SUSE 10, yet I'm lost on the 2nd choice.
Long Live the "Code Warriors" !!

l_____l said:
I believe that is my issue with the new 8GB class 6 card and how my G1 is now slower than the Tandy 1000 I had, long ago. Performance at max CPU speed is now 60-75% SLOWER than when I had all apps on "internal storage" with 7MB free. My ext2 partition on the 8G card is around 830M. I purchased the "appstosd2" from the market, but I'm guessing the s-l-o-w performance is because I have NOT (yet) put the Dalvik-cache on the card's ext2 partition. After reading: http://android.git.kernel.org/?p=platform/dalvik.git;a=blob_plain;f=docs/dexopt.html;hb=HEAD
...it seems that's most likely the "slowness issue". Like launching an app where parts of it have to come from a different hard drive.
I'll try moving the Dalvik-cache to the sd with the apps, but since I only made an 830M ext2 partition, I'd like to view the SD card within Linux Live CD. Perhaps there I could "resize" it to 1200-1400M. Then again, I'd like to keep the apps that came with the device "Market, Browser, Maps etc" within the device's internal memory, while installing pHaT apps to the ext2 partition, such as iMAP weather, aFile, pacman (with flickering screen on 1.5 builds ö) and really large apps that many ppl UN-install and report "I need more space on my phone".
I'm not too new of a noob, however I am a "super noob" when it comes to Linux. I setup my laptop to dual boot Win XP or SUSE 10, yet I'm lost on the 2nd choice.
Long Live the "Code Warriors" !!
Click to expand...
Click to collapse
I've read that having too big Of an ext2 partition can actually have a negative impact. You really don't need more than 500mb unless you are running debian or ubuntu. Moving the cache would be a good idea, and may help the speed issue. B

ubernicholi said:
I've read that having too big Of an ext2 partition can actually have a negative impact. You really don't need more than 500mb unless you are running debian or ubuntu. Moving the cache would be a good idea, and may help the speed issue. B
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Click to collapse
Indeed, that's why I wanted to make the ext2 no more than a factor of 3. (256x3). The SanDisk "Ultra" product seems not to be true "class 6", but rather 4. That's why I went with Transcend. They also make a 16G class 6, but $90 instead of $20 for the 8G.
I did the Dalvik to SD, and the device seems a tad faster, but, I have an app that puts the cache to SD in the FAT32 partition (for users with root access) and that is probably an issue. I will UN-install that app, but it's tough to understand as the coder is French, and the GUI is kind of, well, "did it do what I thought in English?" The name of the app on the Market is: Move Cache for Root by Costa Mlkhael. Does seem to work, but with appstosd2, it is not needed and probably hampers the system as it tries to access cache. I sure uninstalling it will allow cache to the ext2, but I will be left with loads of folders on the FAT side with what was left over. (a nightmare to delete)....yes, phone is a lot faster now with dalvik on the sd's ext2 partition.

alapapa said:
http://lmgtfy.com/?q=dalvik+cache
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...lol this is an infinitely recursive URL

alapapa said:
http://lmgtfy.com/?q=dalvik+cache
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haha the first link takes me to this thread!

alapapa said:
http://lmgtfy.com/?q=dalvik+cache
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This is now a cyclic link as google brings us back to here how funny is that!!!
ROTFLMAO!!!
damn someone already found that.
oh well, whatever, nevermind

metasage said:
Even after searching on Google it seems that the purpose of Dalvik Cache is very convoluted. From what little I understand it's the location where application data stored by the OS... but I could be wrong.
Click to expand...
Click to collapse
ohhh myyyy goshhhh LOL

alapapa said:
http://lmgtfy.com/?q=dalvik+cache
Click to expand...
Click to collapse
the awesome thing is that the first link on google is this thread!
damn i should have read the whole thread first. i thought i would be the special unique snowflake that would discover this first.

How would you restore the SD Cache after a wipe? (To fully be back before the wipe)

Hey all, been spending the past couple days searching and reading various topics on this. My G1 if you rem the post went into the looping thing which I had to wipe to have it come back up. Now I used lucids script which relinked everything yes... including the looping reboot. So started from scratch again. Was times when I DID get it to show up but root, terminal were missing afterwords, Wipe/upgrade again. Now all I have done so far is JUST moved the apps, I havent touched the cache yet. Which at least now it shows my apps installed. Now I just need the config data back (Data) to complete the setup I had again.
How would you have the G1 go back to using the SD for the cache mapping. Would you move the cache (which isnt a good idea) back to the G1 then redo? I just wanna get everything back to 100% the partitions is fine and so since it does boot fine. I just dont wanna attempt to move the cache again only for phone to reboot and wind up missing its apps again and no root support till I wipe and start over again.
I want this all back since I had my G1 since it came out, Market cache is big, which yes I can manually restore that, but I rather do it all clean in one good move.
Anyways if anyone here knows how to relink a cache without it causing issues would be great. (Also the de cache is still on internal too) I did install the img from lucid tho for booting.

No one has any ideas or insight to this one? =/

It depends on what version of app2sd u are using or I should say it depends on the ROM. If you are upgrading to a ROM that uses Marcus's apps2sd u should be fine to follow instructions below. If u are using old apps2sd, then use Lucid's script to re-link to sd card after upgrade.
Copy all files from the sd card back to the phone, upgrade, then put them back on the sd card using apps2sd

Well can I copy the cache over to the internal and so, then move them back? The apps are linked fine to the SD atm, Im using Lucids. JF 1.51 US.
The cache, what is that exactly? Is that just the user data it creates after you run the program or what.

Fresh 2.0d and apps 2 sd.. Internal space decrease

ok so i did the command in the shell and i got /system/sd/apps which is good.
However everytime i install a app my internal memory decreases... My exact process is Wipe Factory wipe cache wipe ext partion... Then i create partion and convert 2 to 3.. I then flash 2.0d ..install a app ..internal memory decreases....WTF!

You shouldn't have converted the ext2 partition to ext3, as ext3 is a journaling FS.
Anyway, the internal storage is still used for /data/dalvik-cache, /data/data, and others. Only /data/app and /data/app-private are moved onto the SD card. It's normal for internal storage to go down after installing apps with Apps2SD.

i just installed sprint nav and went from 101mb to 93...thats right? Avaliabe space doesnt decrease at all!!
And i read on geekfor.me that your suppose to convert 2 to 3

I had to flash darktremors app2sd 2.5 for mine to work properly

Danokan said:
I had to flash darktremors app2sd 2.5 for mine to work properly
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+1 Danokan
also Mickdubs, .... ext 3 is more stable than ext 2 (less probability of lose of data) so you actually did do the right thing by converting it

is there any where in the process were im going wrong.
im using a a data class 6 turbo seris...8gb....
This is bothering me i already wiped twice now ..and im installing back all my apps and losing space..down to 50 mb right now

Did you do the test to make sure your a2sd is enabled properly?
http://geekfor.me/faq/apps2sd/

thats what my first post said!!
it says its working

mickdubs said:
thats what my first post said!!
it says its working
Click to expand...
Click to collapse
your a2sd is working but installing a2sd 2.5 is the only way you will not see significant memory drop on your phone. everything except cache will be stored on your sd by flashing this zip
trust me, I went through the same thing as you til I read up and found this fix

so just flash as zip and be on the way..i apperciate all these quick replys ..xda comminity is strong!

mickdubs said:
so just flash as zip and be on the way..i apperciate all these quick replys ..xda comminity is strong!
Click to expand...
Click to collapse
yes, flash through recovery but as always...do a Nandroid backup 1st. let us know how it goes

ok flashed and THANK YOU.... avaliable space is at 141mb... your d man

[Q] "Phone Storage Space is getting low" with a2sd on Liberated FR008

Search is not working on either IE or FF for me right now, so I'm starting a new thread. Sorry about it, as i'm sure this is a duplicate question. Know that I tried for awhile to search first.
I've got an Aria running Attn1's Liberated FR008 ROM. a2sd has been enabled. However, I've got almost no phone memory left. I've heard that even with a2sd, some of the app dalvik stuff is stored on the entirely insufficient internal phone storage, and I have recently downloaded a bunch more apps. I have used CacheCleaner NG, which did not alleviate the problem. I have also "cleaned up" the Dalvik Cache using Titanium Backup, which found nothing to clean.
I'm wondering if there's some sort of area on the internal phone memory I can clean myself using Astro or something, because it seems that with most of the bulk of app storage being on the SD card, and every app with options to store cache on the SD card doing so, I should have more room on the internal storage.
What do you guys think? Have any of you run into this problem and resolved it without just uninstalling a bunch of apps?

Great question. I've considered a complete clean install, just to regain some internal space.
I wish ****ing Facebook would add an option to cache to SD card - it's a total hog. Going to endure with the Aria until fall and see what's out on AT&T at that point.

I know app2sd from the market has worked for me in the past. I had a ton of apps on my aria and haven't had a space issue
Sent from my Liberty using XDA App

The solution for me was to move the Dalvik cache to the SD card.
DISCLAIMER: Some people report this causes problems, I guess. The information I'm providing explain what worked for me. Following my instructions might cause instability, brick your phone, destroy your house, or eat your second cousin. None of these things are my fault.
I guess when a2sd is installed, it does not by default move the Dalvik cache, which contains files needed for apps to run. The more apps you install, the more that gets installed in this Dalvik cache. Here's how to move the dalvik cache on your phone to the a2sd partition, assuming you've perused the above warnings.
Open Terminal Emulator.
type su and hit enter.
type a2sd cachesdreset and hit enter.
The phone will restart, and it will take a long time, because it's got to rebuild the dalvik cache. You can do it without wiping the dalvik cache by using the cachesd command instead of cachesdreset, but I've read that wiping the dalvik cache doesn't hurt, and can potentially solve some issues? YMMV. My phone took awhile to start up.
Once the phone starts up, you can open something like Titanium Backup, and you should notice that your phone has MUCH more internal memory available. My phone now has 89MB of internal memory available, out of the total 194MB.
Things seem to run a bit slower upon startup than they used to, but after a bit, everything smooths out. And I can install apps again, etc.
Hope this helps.

taliesin1077 said:
What do you guys think? Have any of you run into this problem and resolved it without just uninstalling a bunch of apps?
Click to expand...
Click to collapse
I think that I ran into this very recently. The following thread has some good info.
http://forum.xda-developers.com/showthread.php?t=770146 ... more specifically ... this page that is linked from that thread.

Deal with dta2sd script.

Hi all sorry for a long story, but I may explain how I had dealed with darktemor a2sd script. My be some of you will find it helpfull.
After few(about 5) rom reinstalls I finally managed to get a fast application gready?(87 apps installed) Phone. Every lost attempt reached me some new leasson. I just want to share my successful install with you all.
Started with clean install of #177 cm7, buzz kernal 2.6.32, 3.35.20.10 radio( after formatting data,ext, system, and every thing else but not SD primary partition formatting ), SD speed increase script(4068), Jews ram script, a2sd beta3 script. Then booted the device.
Started terminal, typed "a2sd datasd "( experimental feature in a2sd script) - moves data to ext partition of SD. I've got 512mb ext3, 32mb swap. Then rebooted.
Again to terminal, typed "a2sd reswap" -use swap partition from SD. Then typed "a2sd swappy75 "- set swappiness value to 75. Actually I don't know much about it. But done it coz I have a swap partition in my SD. . Rebooted again.
Again to terminal typed "a2sd heapsize48"- make dalvic heap 48 MB. Is it nice to have larger heap?? . Reboot.
Again to terminal typed "a2sd zipalign "- zipalign ext contents every time you boot the device. Rebooted.
Installed titanium backup, restored the backups of app I have.( 87 apks) . Connected to net, updated every thing. Rebooted to recovery.
Wiped cache and dalvic cache. Rebooted. Viola I have never seen my phone as fast as this. With about 87 apks! Still my phone memory is.
Internal- 99mb free
SD ext - 226mb free/ 480mb total
Cache - 38mb free/ 40 MB total.
Ram - 136 MB free( at the time. Some apps are running in background)
Swap - 109 MB free / 114 MB total?? Dnt know why, but I think I have 32 MB swap when I partitioned my SD.
Total free- 233 mb free/434 MB total.
All the above readings are taken from a2sd GUI in my phone.
What I haven't done.
Never moved dalvic cache to SD as it made my phone lot slower when I've experimented with previous installs.
Never used a2sd GUI to do any of the a2sd commands. All done using terminal. As commands like "datasd " are not available in it.
Never moved a single app using internal app moving feature of cm7, nor used app2sd, link2sd or some thing else.
Never changed install location in cm7 app settings tab. Nor ticked allow app moving.
How do I installed backups.
All backups are installed after I prepared the phone and SD. Ie after execution of the above said a2sd commands. None of the commands are executed after installation. As my experimental installations resulted in lost of apps, when I executed a2sd scripts ( not all, but atlest few).
Titanium backup showed a force close error when I tried for batch operation. Although I have latest pro version. So I do manual back up. Some apks with data, some apk only. Later I will check with some other version of titanium backup.
I never use any apk moving program, let all be in the hands of cm7#177 and dta2sd beta3. Thanks to creators .
I have given a fix permission after I installed the backup from cwm recovery. Hoping to avoid force closes.
Every thing went ok for now. I am posting this as soon as I had done the above. I will check with some
more installations and usages in the comming days. And surely will report if I found bugs/ hangs etc.
So I hope u will help me. And also my post may help some of you. Thank u all xda members.
Sent from my HTC Wildfire using XDA App

Found first error...
Phone takes a long time to boot if cache and dalvic cache are wiped. Just about 10 min. But every thing is fast after boot.
Sent from my HTC Wildfire using XDA App

showlyshah said:
Found first error...
Phone takes a long time to boot if cache and dalvic cache are wiped. Just about 10 min. But every thing is fast after boot.
Sent from my HTC Wildfire using XDA App
Click to expand...
Click to collapse
Its not an error. When you wipe the Dalvik Cache, the phone has to rebuild it at boot, so, its a totally normal thing. (And precisely why new ROMs take a long time to boot)

ya i know it and have experienced it several times. same rom too. but it is not the same now. usualy got 5-6 min. but since i had done the above a2sd work it takes 5-6 more to boot. ie a total of 10+ min. may be due to the reason that data had moved to sd. and a slow read/ write speed may cause the problem. but mine is 8gb class4 card. class4 may be enough?? also zipalign is also enabled.
hence i think..
rebuilding dalvic cache+ slow read/write speed+ zipalign+ initiations = slow startup.
Sent from my HTC Wildfire using XDA App