Lately, I've been flashing a bunch of different ROMs, and in each one, they require you to have a certain amount of your memory partitioned. I'm not too experienced in this particular area and I've been wondering what is the point of all the partitioning?
Why can't we just have one partition and run things off of that like with a computer running on windows??
What are the differences between ext2 and ext3 and so on?
So far, I've only been able to find out that the swap partition is for memory extension when the phone is currently using all of its ram, it can convert some of the sd card's memory to use for programs. Can anyone provide more insight on this?
I've asked myself the same questions .... hope someone will explain...
hacker01 said:
Lately, I've been flashing a bunch of different ROMs, and in each one, they require you to have a certain amount of your memory partitioned. I'm not too experienced in this particular area and I've been wondering what is the point of all the partitioning?
Why can't we just have one partition and run things off of that like with a computer running on windows??
What are the differences between ext2 and ext3 and so on?
So far, I've only been able to find out that the swap partition is for memory extension when the phone is currently using all of its ram, it can convert some of the sd card's memory to use for programs. Can anyone provide more insight on this?
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It would be helpful if you mentioned what phone you're using.
Generally the reason you have a /data and /system partition separately are so that you can either upgrade or reinstall Android without losing your data. If you reflashed whatever ROM you're on right now again, without wiping anything, all of your apps and settings would still be there (although any mods you flashed to modify the ROM itself would need to be flashed again).
System - Holds Android itself and any apps that came with the ROM. Some ROMs (or rather updater scripts inside of ZIP files) will install some apps in the data partition to save space.
Data - Your settings and any applications you installed.
Sometimes you WILL have to wipe everything to go to a different ROM, but for the most part if you're on an official ROM that came with your phone, and your carrier pushes an update, you don't have to.
I'm guessing you have an older phone if you need to make a swap file. A swap file is like RAM in the form of a file; if your phone runs out of usable RAM, it can use the [slower, but useful] swap file, which is like memory you reserve from storage [your MicroSD card]. Windows and other OS's use swap files too, but given how much RAM we have in computers today, we hardly ever use it.
EXT 2 fs - A non-journaling file system. It's quicker than EXT 3 and takes up less space for itself in memory (not for files, just for itself), but it's more susceptible to corruption if you randomly turn off the phone while a file is being accessed.
EXT 3 fs - A journaling file system, which means that it keeps track of any file operations within itself. While it's slower than EXT 2 and takes up more space, it is more reliable and is safer in terms of file integrity.
There's also EXT 4, but only certain phones are compatible with that, mostly Samsung Galaxy S phones.
tl;dr: It keeps everything modular.
Thanks for the explanation. It helped
Sent from my PC36100 using XDA Premium App
I put this short guide together because I tend to see a lot of confusion regarding what a "wipe data / factory reset" does to your phone.
These are the steps you should take before loading a new ROM:
1) Download your new ROM and relevant supporting or needed files like modem, alternate kernel, etc., and place them on your internal SD.
2) Backup your applications, settings, messages, etc., with a backup tool like Titanium Backup, image specific backup tool, etc.
3) Boot into recovery and run a “wipe data/factory reset"
4) Follow the developers ROM loading instructions.
When you perform a “wipe data/factory reset” the content of the following directories are deleted :
/data
/cache
/datadata
/sd-ext
/sdcard/.android_secure
Nothing else on your SD card (internal or external) outside of these directories is modified so it is safe to leave files outside of the above mentioned directories without fear of losing them. Your external SD card and SIM do not need to be removed. The goal here is load a new or updated ROM in as much a clean environment that you can. Files left behind in these, especially cache and davlik-cache can cause some of the strangest problems. The kind that nobody can really resolve.
/cache - This is the partition where Android stores frequently accessed data and application components to make these, as implied, respond much faster as well as faster to retrieve / access.
/datadata – This directory contains the library, database, user specific configuration files as well as log files for its specific application installed in the /data directory.
/data directory is where your contacts, messages, settings and apps that you have installed go. Wiping this partition essentially restores it to the way it was when you first booted it, or how it was after your last custom ROM install.
If your ROM uses an /sd-ext partition on your SD card for data storage your /data directory is mapped to /sd-ext and wiping the /sd-ext directory will result in losing your data.
/sd-ext is used for apps moved to your SD card. Your Android OS runs natively in an ext format while your SD card has a fat32 format, which is used typically for USB storage devices, Windows computers, etc.
The sd-ext partition is an additional partition on your SD card that acts as the /data partition when used with certain ROMs that have APP2SD or data2ext enabled. It is popularly used on devices that have little memory allotted to the /data partition. A misfortune that in my experience, Captivate does not partake in. Still, users who want to install more programs than the internal memory allows can take advantage of this partition and use it with a ROM supporting this feature.
The folder named .android_secure is where apps are stored when you perform the "move from phone to SDram/SD card" operation.
Consider this, Apps2SD uses the fat32 portion of your SD card, which is obviously limiting because it isn't Androids native file system. However, if you format your SD card, or partition a part of it as a ext file system, you can trick the phone into thinking it's part of the Android OS native environment. This will allow you to move applications, widgets, even cache and davlik cache over to it.
Disclaimer! I am not responsible for any damage you may cause to your phone or SD Card if you try to enable/use sd-ext.
To enable sd-ext in ClockWork Mod (ROM Manager):
Boot into CWM
Go to Advanced
Then to "Partition SD Card"
Choose an sd-ext size
Then choose a swap size, or not. Swap is just like windows' virtual memory. The system will use it when you're running low on RAM and use it as temporary RAM storage. This is where you'll probably see an increase in speed.
Just for fun I put sd-ext at 512MB and Swap at 64MB which is probably more than plenty for the swap. The swap will assist a little with memory and with the extra space I can move my apps over to it with a program like App2SD or in most custom ROMs nowadays just use the "move to USB" option in "Manage Applications". Titanium Backup will also move apps to SD for you and I'm sure you can find plenty more in the market.
You can also use a tool like Minitool Partition Wizard:
1. Open Minitool Partition Wizard
2. Delete Existing Partition from SDCard (Backup data first!!)
3. Create Fat32 Partition
Note: Set all partitions to PRIMARY (Steps 3 - 6)
4. Create EXT2 Partition (System) about 150MB-200MB depend on ROM
5. Create EXT2 Partition (Data) about 150MB-250MB
6. Create EXT2 Partition (Cache) about 50MB
Personally I don't see a need to do any of this on either of my Captivate phones though I have played with it on my DEV phone.
And since it does play a big role and needs to be cleared at times...
Davlik-Cache - dalvik cache is a program cache area for the program "Dalvik". Dalvik is a java based virtual machine that is the base for running your (.apk) programs. In order to make access times faster (there wasn't a JIT compiler installed by default until Android 2.2), the dalvik-cache is the result of dalvik doing a optimization of the running program/s. This optimization is kept so that it is then re-used every time you use your application/s. By default, davlik-cache is located in your /data partition.
No, I'm not looking for donations. Just trying to clarify things for some.
Great info, but a "guide" assists you in doing something, this is just straight info.
While I initially intended on writing it to guide flashers into the benefits of a wipe data / factory reset, and avoiding the myriad of strange issues experienced, I can see now where it can more construed as informational. Hmmm... maybe I'll add more to it or ask a mod to change the title topic for me.
Regardless, my hope is that some people get some benefit out of it otherwise I've only wasted my time.
Thanks, I've been wondering for a while what that actually did.
Great start for a guide that should clear the boards up a bit. I vote it to be stickied after adding a bit more info on backing up, partitioning the sd card, dalvik cache, etc.
I think it is important to explain that a reset should not be done after flashing a custom ROM because it deletes the Dev's settings/data/non-system apps. Instead flashers should either reset after flashing back to stock or before flashing a custom ROM over the current custom ROM.
Cozmo1 said:
I put this short guide together because I tend to see a lot of confusion regarding what a "wipe data / factory reset" does to your phone.
When you perform a “wipe data/factory reset” the content of the following directories are deleted :
/data
/cache
/datadata
/sd-ext
/sdcard/.android_secure
/cache - This is the partition where Android stores frequently accessed data and application components to make these, as implied, respond much faster as well as faster to retrieve / access.
/datadata – This directory contains the library, database, user specific configuration files as well as log files for its specific application installed in the /data directory.
/data directory is where your contacts, messages, settings and apps that you have installed go. Wiping this partition essentially restores it to the way it was when you first booted it, or how it was after your last custom ROM install.
If your ROM uses an /sd-ext partition on your SD card for data storage your /data directory is mapped to /sd-ext and wiping the /sd-ext directory will result in losing your data.
/sd-ext is used for apps moved to your SD card. Your Android OS runs natively in an ext format while your SD card has a fat32 format, which is used typically for USB storage devices, Windows computers, etc.
The folder named .android_secure is where apps are stored when you perform the "move from phone to SDram/SD card" operation.
Consider this, Apps2SD uses the fat32 portion of your SD card, which is obviously limiting because it isn't Androids native file system. However, if you format your SD card, or partition a part of it as a ext file system, you can trick the phone into thinking it's part of the Android OS native environment. This will allow you to move applications, widgets, even cache and davlik cache over to it.
Nothing else on your SD card (internal or external) is modified so it is safe to leave files outside of the above mentioned directories without fear of losing them.
If you plan on trying several different ROM's and/or updating your favorite ROM every time a new version is released you need to invest in an application like Titanium Backup or one that comes with your ROM if it's supplied with one. MIUI includes one that works extremely well. Performing a “wipe data/factory reset" after loading your new ROM and before booting into it should provide you with a smoother transition to your newly chosen or upgraded ROM. Having a standard backup and restoral process should help you enjoy it quicker too.
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Here is something I keep in a word file to help answer what you are also trying to answer. It is a bit shorter and simplified but it may help to polish your thread for us simpletons.
Dalvik cache is a place where the Android OS re-compiles the executable programs the first time to optimize them. It does this when you make a major change like replace the kernel/modem. Clearing the Dalvik cache will force Android OS to recompile the apps for the the new kernel/modem. This can take time on the first boot after clearing the Dalvik cache.
Also the main data Cache is used by the Android OS at run-time to write temporary files for specific reasons. You want to clear this out so it doesn't re-use the old cached data.
Manually clearing both caches allows the new kernel/modem to be installed in a "cleaner" environment. It's just preventative maintenance.
snowake said:
I think it is important to explain that a reset should not be done after flashing a custom ROM because it deletes the Dev's settings/data/non-system apps. Instead flashers should either reset after flashing back to stock or before flashing a custom ROM over the current custom ROM.
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Click to collapse
This actually makes perfect sense to me. I have modified my OP because of your input. Thank you very much, snowake!
Cozmo1 said:
This actually makes perfect sense to me. I have modified my OP because of your input. Thank you very much, snowake!
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Click to collapse
do u have more info about "format your SD card, or partition a part of it as a ext file system" or how to do that.
i have read someone format part of the sdcard (class 10)to ext 2 or 4,to make the write n read faster.is that what you mean.can u guide me to the right direction.thank in advance.
? ? ? about this......(However, if you format your SD card, or partition a part of it as a ext file system, you can trick the phone into thinking it's part of the Android OS native environment. This will allow you to move applications, widgets, even cache and davlik cache over to it.)
Cozmo1 said:
This actually makes perfect sense to me. I have modified my OP because of your input. Thank you very much, snowake!
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Click to collapse
I struggled with all of this my first first few flashes.
xpakage said:
...Dalvik cache is a place where the Android OS re-compiles the executable programs the first time to optimize them.
...
Also the main data Cache is used by the Android OS at run-time to write temporary files for specific reasons.
Manually clearing both caches allows the new kernel/modem to be installed in a "cleaner" environment. It's just preventative maintenance.[/I]
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Click to collapse
That is much more boiled down. I looked back at the "how to flash" threads and a couple good explanations on custom roms. None explain this that I found.
Cosmo, here are some more thoughts on misunderstandings I have had and seen posted. Like post above I pasted from my notes, so may be incorrect.
Bootloaders: Same for Froyo/Eclaire in both i897 and i9000 roms. GB requires new bootloaders, but i897 are apparently cross-compatible. However, issues seem to pop up on i9000 roms with GB i897 bootloaders. If flashing back to Froyo, use the full jf6 stock, not cezar's stock eclaire without bootloaders.
Using Tibu: If no useful data (i.e. Bookmarks on dolphin) then simply click data only when restoring user apps. Typically no issues when restoring user apps after switching Android versions. However, system apps should not be restored because of the rom customizations. Especially when switching to GB because it uses different directory structure. I do not seem to have issues when staying on same version and restoring foreground (user accessible) apps with data only or restoring green text color sys apps with Tibu as icon (i.e. Accounts).
Rom manager: really only need the app if flash to stock and need to flash rom directly from cwm. If so, then flash cwm (top button in menu) and choose phone. This places update.zip in /sd, which is opened after selecting "reinstall update" in stock recovery. Usually have to select it twice for it to work. This will replace ATT stock 2e recovery (blue text) with cwm 2.5 (froyo).
Voodoo color, lagfix, sound: must either be included in kernel. Lagfix simply allows user to format sd as ext4 (linux). Color balances display so less blue iodes are used and color is more realistic. Sound allows clearer sound through headphones through tweaks enabled in voodoo app. If sound is not in kernel then purchase voodoo pro in market and it will install it into the kernel (if rooted, even if stock).
Thanks for clearing that up!
- Aaron
Updated with more details.
Really, really useful. Had no idea partition options were available to this extent! Especially swap. By mini tool are you referring to Easus' program? I am definitely checking this out tonight. Thanks!
Great guide. In order to clear
/sdcard dir I master clear it after flashing to stock. Is there an alternate method besides deleting dirs myself?
snowake said:
Great guide. In order to clear
/sdcard dir I master clear it after flashing to stock. Is there an alternate method besides deleting dirs myself?
Click to expand...
Click to collapse
That is probably the safest way to do it within the phone itself. An alternate way would be to mount it to your computer:
In Windows right click the drive that was assigned to your internal SD card and then click on format. By default it'll most likely set you to Fat32 and if you click format it'll say its complete, but nothing will be deleted. Android being a Linux OS doesn't use fat. You can format it by choosing exFat, but by doing this...
!!!WARNING!!! be aware that you will lose everything on your internal SD card AND your external SD card.
Emphasis placed mainly for others that read this and might not know.
Safer and easier to do it within the phone.
snowake said:
Really, really useful. Had no idea partition options were available to this extent! Especially swap. By mini tool are you referring to Easus' program? I am definitely checking this out tonight. Thanks!
Click to expand...
Click to collapse
This one is from MiniTool, though I wouldn't be surprised if Easus owned them. I didn't investigate to confirm. You can get the free home edition of MiniTool Partition Wizard here.
Very nice infos. Deserves a sticky, although, probably in a different thread.
Some information on what "Master Clear" in Odin would also be helpful - I have never trusted my phone to 'truly' clear everything on the phone, I have found the Odin Master Clear option to be much more complete.
It is a bit odd, I do this with my PC every six months, I back everything up and format the drive and start over again (after running Spinrite on all the drives) - I do this on / around New Years and again over 4th of July weekend and I decided this past weekend to also do the same with my smart phones (4 Cappies) and tablets (Ipad and 2 Android tabs) this past weekend.
It gives me that sort of squeaky clean feeling and seems to make my devices run smoother. Maybe its all in my head, dunno *shrugs*.
One thing I can say however, I have not had a hard drive go bad on me since I started the Spinrite thing 10 years ago (I still have an 8 GB hdd in my desktop that is working!!).
Any decent update(r)-script will do this for you.
Sent from my Infuse 4G
littlewierdo said:
Very nice infos. Deserves a sticky, although, probably in a different thread.
Some information on what "Master Clear" in Odin would also be helpful - I have never trusted my phone to 'truly' clear everything on the phone, I have found the Odin Master Clear option to be much more complete.
It is a bit odd, I do this with my PC every six months, I back everything up and format the drive and start over again (after running Spinrite on all the drives) - I do this on / around New Years and again over 4th of July weekend and I decided this past weekend to also do the same with my smart phones (4 Cappies) and tablets (Ipad and 2 Android tabs) this past weekend.
It gives me that sort of squeaky clean feeling and seems to make my devices run smoother. Maybe its all in my head, dunno *shrugs*.
One thing I can say however, I have not had a hard drive go bad on me since I started the Spinrite thing 10 years ago (I still have an 8 GB hdd in my desktop that is working!!).
Click to expand...
Click to collapse
I can run some tests on Odin's master clear to confirm what it does. Initially I would believe it does the same as a "wipe data / factory reset", but testing should let us know for sure. I'll test it this weekend. Maybe sooner.
Awesome to hear that I'm not the only advocate for SpinRite and I still use it a lot though not every 6 months like you do. It's definitely worth having and using.
MikeyMike01 said:
Any decent update(r)-script will do this for you.
Sent from my Infuse 4G
Click to expand...
Click to collapse
I totally 100% agree with you, MikeyMike01. Unfortunately, not all update scripts are created equally Asides from teaching people how to script themselves or parse through it, a task I do not have the time or patience to tackle, this it probably the easiest and best way to have users try to avoid the many and strange issues posted that possibly / most likely could've been avoided by using the tools at their disposal.
On a side note... I didn't notice you got yourself an Infuse 4G. Congrats! How do you like it? I've been out of contract for almost a year now and wouldn't mind upgrading (my wife is in contract), but I haven't seen anything really worth upgrading to or that does something I really need/want that the Captivate cannot, atm. I haven't looked up any specs and reviews on the Infuse yet tho.
A few days ago I got a "new" windows mobile phone in, and I decided that I would cook a rom for it myself to get all the functionality I wanted, but after testing a few of my own and other roms I've got some questions about the different memories of my phone.
- It's a Sony Ericsson Xperia x1i, but I think my questions would also apply to other windows mobile phones.
- I'm cooking and running other peoples windows mobile 6.5.3 roms
- The phone has 512MB of flash and 256MB of RAM built in.
- I'm using Twinge Kitchen 1.10 for cooking the rom and importing cab's of the apps I want to use
I've tried roms of vastly different sizes, but the storage memory always remains the same. My question is, how is the flash memory on a windows mobile device used? I'm assuming the bootloader, radio and some other things might have their own partition, and then a partition for the rom, and one partition is for storage memory. Am I correct?
If I flash my phone to a small rom will the space I save on that be wasted? Is there a way to make the free space available as storage memory?
I've tried putting all the apps I wanted to install into the rom, and that worked fine, but on first boot they installed themselves into the storage memory, so I would have been just as well off by installing them after flashing the rom. Is there a way to add apps to a rom, and have them integrated in it in such a way that they don't require further installing after flashing, just running the apps from the rom like all the regular stuff is. (this is probably done by people who know how to cook roms, but I can't find an explanation on how to do it anywhere)
I would rather cook a minimalistic rom and use the freed up space as storage memory, and then install my apps manually, that way I could uninstall them whenever I wanted. Or would having those apps intergrated into the rom save me more space because they would be compressed?
Either way I would like to know if there was a way to increase the storage space, and make the rom space smaller. I guess I would need a partition manager for windows mobile/CE that can resize without data loss, and resize the rom and storage partition with the phone running, or perhaps on the PC, with the phone connected with the USB cable and running in bootloader mode.
I have another question about RAM, my phone has 256MB RAM, but it shows as about 200MB program memory of which about 50 in use with no apps running. What is the remaining 56MB used for? Is there a way to change this amount?
I have used Windows Mobile for quite a while now, but this is the first time I've tried cooking a rom, or even thought about partitioning the built-in flash, so to the more experience people the awnsers to my questions might be obvious, but to me they are not.
I have thought of one possible way to re-partition the built-in flash, but I don't know if this can be done this way without messing anything up.
I could run Android from the sdcard, and resize the partitions on the phone-flash while in Android, but is there even an app that will let you resize those partitions in Android? Would this work without data loss, or if not would the bootloader be ok so I could flash the rom again in the newly resized partition?
I've had three WinMo 6.x devices (1 GPS and 2 phones) and both were able to have things stored on its flash memory. In fact, isn't that where the "My Documents" folder is?
JamesDisbrow said:
I've had three WinMo 6.x devices (1 GPS and 2 phones) and both were able to have things stored on its flash memory. In fact, isn't that where the "My Documents" folder is?
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Click to collapse
Yes, but I think you are mis-understanding my questions, I don't want to just store things in it's flash memory, that's no problem. I want to resize the partitions on the flash memory, using less flash for the rom, and more available as storage space.
I have been researching further, but I keep coming up empty. I can't find any android or windows mobile app that'll even let me see the different NAND flash partitions, let alone manipulate them.
I could try and get a linux partition manager to work on android, but the more I think of it, the riskier it seems.
I've also been looking into using MTTY, but I can't find any information on what the commands are, except for tasks 28,29 and 32, and none of those will help me. I don't know if MTTY even has the capabilities to manipulate the partitioning.
Hi all,
I have searched for an answer to this question for a couple days now and cannot seem to find an answer anywhere; at least one that relates to this device.
What I would like to know is if it is possible to resize the partitions on the my phone. I am looking to mod the size of the rom, cache, and data.
For instance I have cyanogenmod 7 installed (with latest tiamat kernel if that matters) and CM7 is only taking up about 152MB out of the system roms size of 575MB. I do not know how big my cache partition is but would be curios as to what tool could show me that too.
What i want to do then is shrink the amount of rom availible to CM7 to something closer to 170MB which would free up a fair amount of rom for cache and data.
Any ideas?
Thanks
You would have to make some major changes to the ROM and kernel. The easier way would be to get a large SD card and create SD ext partitions and use an apps2sd ROM. There is plenty of space though on our phones for apps and storage. The data partition is 1.1 GB and most roms will let you move apps to SD without extra partitions on card. Creating those partitions on SD will allow the phone to treat them like /data though.
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Using Titanium Backup, you could also convert some user apps to system apps. This would move them to the rom storage.
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