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What filesystem does the Inspire use?

I am just curious what filesystem is in use on the Inspire. I'm assuming EXT3 but I'd really like to have EXT4 like we had on the Captivate. The phone flew even faster with EXT4 than it did on EXT3 and it flew pretty fast on EXT3 as well.

Pretty sure it is ext3. D1ll1gaf's rom has an optional kernel that runs on ext 2. I have not seen ext 4 anywhere.... But who knows.

i wanna say stock it runs EXT3, and i'm pretty sure i've seen rooted roms running EXT4

^^^^^ agreed.

howto apps2sd as ext4

Ok. So lots of talk about ext for apps2sd and how it's being mounted as ext2 even if you formatted to ext4 etc.
Also talk about how journalling hurts performance and such. We'll tackle all those points here.
1. Howto fix the mounting of your ext partition in the meantime till your mod updates their software.
A. Pre-requisites
You must have already partitioned your sd card with an ext4 fs for apps2sd. You can do this in recovery or some other app.
You should also get the program file expert. It's awesome. But any filemanager that has root ability will work. You can do all this in terminal too so whatever floats your boat. I'll use file expert below.
B. Remount your system fs as read/write (not sure if it's actually needed since /system is mounted rw by most mods already... but it can't hurt). You can do this in file expert by hitting menu and selecting More, then the top option labeled "Mount", select read write. It should say success.
You can also do this in terminal but like i said above, i dont think this is absolutely needed but i always assumed it was so never tried this not doing it.
C. go back down directories using the back key till you hit /. Then goto /system/etc/init.d/
D. select S05mountsd (the S0# isn't important here so if yours is different dont worry). Once selected, hit menu and select file operations. Select permissions and change permissions to read/write all.
E. Open the file with a text editor of choice. Scroll down the file to the part that has the command with -t auto in it. It should be pretty obvious, and it's near the end.
Change -t auto to -t ext4. It doesn't matter if your fs is actually ext2 or ext3, mounting as ext4 is always better. The ext4 block allocator and general code is more efficient even if you dont use ext4 features.
You may also want to add an option to the options list data=writeback. This disables journal caching of actual data and only caches metadata. This is really integral to performance on such a slow medium like sd cards and we'll discuss that later.
Save your file and exit.
F. Reboot your phone. You should now have your sd-ext mounted as ext4.
2. data=writeback and why?
there are multiple modes of journalling available to ext4. The default is ordered. This means that there is a specific order that information is written to the fs to ensure that nothing is lost that is said to be written. This means metadata about the fs and file data is both cached in the journal. Safe but slow.
data=writeback still allows crash protection but means you may lose actual newly written data. Your fs wont be corrupt, but your file may not have gotten those last updates you were writing and had not synced yet. It's a pretty decent compromise.
There are other forms that offer better performance but basically remove journal integrity and we're not concerned with those.
There are also options that determine the interval of journal syncing and you can find that information on ext4 man pages.
Why do we care so much about performance here? because sd flash is slow and finite. A journal file is like swap in that it is a static file that's contents get written to anytime you write to your fs. On a normal hdd, it's not noticeable really but on a class 6 SD card, you are going to notice having to write everything twice to your sd card. So we choose writeback mode to remove that double writing and only cache fs metadata updates so that the integrity of the filesystem isn't hurt, and only that particular file that we crashed prior to syncing gets effected. 99% of the time this is fine and perfectly safe and way better than nothing.
3. So if journalling can hurt performance by using up write bandwidth to a medium we are writing other stuff on, wouldn't swap be bad too?
Yes. Swap should only be put on sd cards if you absolutely need it or your phone wont work. Aside from stressing the card, the bandwidth to read/write is extremely small for something you basically have to be interactive with and move to and from ram. Additionally android complicates matters by managing memory at a higher level than the kernel and this means that swap is ignored as a portion of memory. So while technically userspace apps deal with swap transparently, the low memory manager of android will operate as if you didn't have swap...which defeats the purpose.
Use swap as a last choice.
Also, the ability to make swap partitions and swap files is a common issue in linux-land. It's best to use a partition as this removes fs overhead but it becomes even more of a concern when you put it on an ext4 fs with journalling active. With default settings, a swap file will be considered just another file and the journal will cache the data and metadata updates (very bad for performance). if you use swap on an ext4 fs that's actually mounted as ext4 you _NEED_ to make the data option writeback. You will be very disappointed if you dont.
4. Other important notes:
If you use any ext4 specific options like extents, you will no longer be able to read the files written by recovery programs that have not been updated to mount fs's as ext4. Also, just enabling extents doesn't convert data on the fs to use them. You have to write the files while the option is enabled to see their benefit. This is more easily done by putting the card in an actual linux computer and mounting with the correct options and copying the data from the filesystem and then back again ....not for the novice. Though any new files written will automatically have extents even if you dont redo all current data. So best to bother with that after a fresh install prior to restoring apps.
You may also be thinking... Why do i even need a fat fs, i can make the whole thing ext4 and it will be awesome! You would be right, it would be awesome. But it's not so easy. A couple things have to be done in order to make everything written world rewritable and accessible on such a partition. you would have to setgid to a group like "sdcard" to a directory in this new fs and give it rwx group permissions and then have all users current and future become part of that group and mount bind the directory to /sdcard. Needless to say, recovery apps would have to also be updated. Then you could make your main sd partition any fs your kernel supports.

Nice post, cm7 and diet gb I build already have -t ext3 set, do you think ext4 would make much difference?

ext4 has a better block allocator and other features both backwards compatible and ext4 specific. There's really no reason to not mount ext2/3 and 4 as ext4

Thanks for the answer, This is also in the kernel I compile,
CONFIG_EXT4_FS=y
CONFIG_EXT4_USE_FOR_EXT23=y
CONFIG_EXT4_FS_XATTR=y

Yes, i began my work on the kernel tonight and noticed that in the latest kernels at least that ext4 is being masqueraded as ext2 and as i thought early on as might be the case, that the reporting of the partition as being mounted as ext2 is a bug that has been squashed in the newest vanilla kernels.
This is still an issue, but not a serious one. FS repair tools and such may bug out when trying to found out what fs they're dealing with as the kernel reports the wrong ext version but the functionality of the fs is not affected ( you still get journalling and all that jazz).
So this is less of a performance issue (cept the adding of data=writeback) and more of an issue with other programs needing to see the correct fs.

Ur Diet 09.05 still did not see ext4 partition by Titanium.
carz12 said:
Thanks for the answer, This is also in the kernel I compile,
CONFIG_EXT4_FS=y
CONFIG_EXT4_USE_FOR_EXT23=y
CONFIG_EXT4_FS_XATTR=y
Click to expand...
Click to collapse
Sent from my Gingerbread on Sapphire using XDA Premium App

If the kernel you're using is one of the newer kernels (probably anything after 2.6.32...but you should be using something much newer) then it likely doesn't even have ext2 or ext3 compiled in. It's all just ext4 like it should be. The issue you still may have however is that the kernel reports the lower revision extfs because ext4's driver accepts the ext4 fs but the kernel is checking for ext2....
Basically, we are asking if this is an ext2fs. The ext4fs driver answers cuz it's all there is and it's masquerading as ext2 and ext3 and ext4. So it looks and sees ext4 and says, hey, i can read this and returns YES. Now the answer yes was to the question of ext2, so that's what gets reported everywhere, but internally, ext4 knows it's got an ext4 fs. mount options that normally would error out with -t ext2 are accepted because the fs driver isn't really ext2 and it knows the fs isn't either so the mount options pass.
This is a kernel bug in an aesthetic and practical sense. Functionally it's all working as intended but other apps and users will get confused as to what exactly is the filesystem, ext2, ext3 or ext4. It can't know without probing the fs itself. Which is stupid for many applications.
Supposedly the latest kernels have a patch to fix this to correctly report the correct fs revision of ext. Though perhaps that hasn't been pushed to linus's branch yet.
In any case, you still should be modifying the mount options to use data=writeback so you're not clogging up the little SD bandwidth you have with data caching in the journal. You really only need fs metadata caching so you dont bork the entire partition on a crash. data=writeback does that, but default is data=ordered.

thank you for such a good post!

[Q] What are the benefits of formating the sd to ext/swap etc?

I'm a Linux user so I know what swap, ext2, ext3 etc technically means. What I don't understand is what are the *actual* benefits of formating my SD Card to these formats. I've run into a lot of guides and how-tos but no one cares to explain why to do it.
So to sum up:
Does the Android System actually cares if I create these formats?
If it does, will I notice actual increase in performance?
What about apps2SD?
What kind of format do you recomend?
I have an HTC Desire and I'm using CyanogenMod, Oxygen and MIUI in rotation (means I replace one with another every couple months).
Thanks in advance!

aventinus said:
I'm a Linux user so I know what swap, ext2, ext3 etc technically means. What I don't understand is what are the *actual* benefits of formating my SD Card to these formats. I've run into a lot of guides and how-tos but no one cares to explain why to do it.
So to sum up:
Does the Android System actually cares if I create these formats?
If it does, will I notice actual increase in performance?
What about apps2SD?
What kind of format do you recomend?
I have an HTC Desire and I'm using CyanogenMod, Oxygen and MIUI in rotation (means I replace one with another every couple months).
Thanks in advance!
Click to expand...
Click to collapse
Faster SD Card speeds for app2sd, thats mainly it. If you don't use A2SD there isnt much point to it, but if you do it can be very useful. What some people do though are format their System and Data partitions to EXT2 or EXT4 so then the whole system is faster all around and is a large improvement over stock rfs.

fowenati said:
Faster SD Card speeds for app2sd, thats mainly it. If you don't use A2SD there isnt much point to it, but if you do it can be very useful. What some people do though are format their System and Data partitions to EXT2 or EXT4 so then the whole system is faster all around and is a large improvement over stock rfs.
Click to expand...
Click to collapse
Ok so if make an ext partition, the apps that are stored in this partition will run faster. That sounds fair. Should I have both ext and FAT partions? And if I do, how does Android know where to put the apps? Also how about swap?

aventinus said:
Ok so if make an ext partition, the apps that are stored in this partition will run faster. That sounds fair. Should I have both ext and FAT partions? And if I do, how does Android know where to put the apps? Also how about swap?
Click to expand...
Click to collapse
No need for swap, and yes EXT is automatically recognized by android for a2sd, but make sure your ROM supports it. You would have an EXT partition between 256mb-2gb max, and then the rest would be FAT.

fowenati said:
No need for swap, and yes EXT is automatically recognized by android for a2sd, but make sure your ROM supports it. You would have an EXT partition between 256mb-2gb max, and then the rest would be FAT.
Click to expand...
Click to collapse
Ok! That was really eye-opening! Thank you so much!

no problem!

ICE DS v 4.2 ICS 4.0.4 Sense 3.6 with ext3

hello everybody!
I tried to find an answer on this on the ROMs thread but I couldnt so here it is;
Can I use ICE DS v 4.2 with ext3 only? If so, can I disable afterwards ext4 support?
Thanks

why wouldnt you use ext4? it's an advantage thou. but if you dont want to use ICE DS in future, just revert to ext3 by using 4EXT Recovery.

For the amount of internal memory that our devices have there is no matter whether you use ext3 or ext4. Also the install script of the ROM itself will format the partitions as ext4 upon flashing so there is not much choise actually If you like to go back to ext3 after flashing 4EXT Recovery can do this without losing any data
Sent from my HTC Desire S

Thanks for the quick replies..
When I used a stock ROM with a rooted Desire, I remember discussions about the disadvantages of ext4.
The idea as I understood, was that ext4 was more likely to create filesystem corruption in case of an abnormal shutdown of the phone, eg battery removal, expecially if it used to extend phone memory to the sd card via proper partitioning.

It is exactly the opposite. The ext4 file management will prevent corruption in case that a read/write process gets interrupted by a battery pull or similar. Search Google for ext4 there are all the benefits described on a Wikipedia article.
Sent from my HTC Desire S

amidabuddha said:
It is exactly the opposite. The ext4 file management will prevent corruption in case that a read/write process gets interrupted by a battery pull or similar. Search Google for ext4 there are all the benefits described on a Wikipedia article.
Sent from my HTC Desire S
Click to expand...
Click to collapse
This.
ext4 wouldn't exist, or developed if ext3 is better.

[Q&A] 2 GB External Data -- Hefe Hook Kernel and others

The Hefe Hook kernel allows you to mount a partition of your microSD as /data, getting 2 GB (or more) for your apps and their data.
Please ask your questions here about installation, use, or general approach.

This is great @jeffsf and can u show me how to re-partition the "real internal" storage? I mean expanding the /system since u put the /data out of it. Thanks man
Sent from my GT-N7000 using Tapatalk 2

daothanhduy1996 said:
This is great @jeffsf can u show me how to re-partition the "real internal" storage? I mean expanding the /system since u put the /data out of it.
Click to expand...
Click to collapse
Yes, you've hit on another of the reasons I've been exploring using the microSD for "live" storage. It's one thing to use potentially slow storage for photos that you basically write once or "app to SD" where you read the APK at boot time, make sure your ODEX in the Davlik cache is good, then generally read from the internal-flash cache. It is another when that memory is being read and written "constantly" when your phone is running.
The good thing is that once /data is not part of the internal flash filesystem, you don't have to worry about one ROM (kernel) thinking it begins at one place and another saying it starts at another. Previously, if one ROM had one /system size and another and a different one, the next partition, /data, would look to be corrupt when you swapped ROMs.
As a warning, not all users have fast microSD cards. Some that say "Class 10" on them really are dogs, especially for small reads/writes. The "Class" ratings are for sustained writes, as you would have with a camera recording video. If your ROM is "external /data" only, or even defaults to that, be prepared for a slew of "Your ROMs sucks. It is so slow." complaints.
You'll also need a way to automate formatting the card. It can be done on the phone, as long as you aren't trying to preserve any data.
As I recall, the layout of the MTD partitions is done in drivers/mtd/onenand/samsung_galaxys4g.h I would be careful not to move the partition boundary for efs, as you'd have to move the data it contains in your updater script. Repeating the warning about not moving the boot and recovery partitions is probably a good idea as well!
Your build tree may need some of these values, or at least think it needs some of these values. For example, device/samsung/aries-common from the CyanogenMod/cm-11.0 (KitKat) branch calls out NAND page sizes, partition sizes, and flash block sizes. I haven't looked in detail at your build tree so I can't comment on how it might handle things differently than the CyanogenMod one.

itzik2sh said:
Hi
I hope I don't ask anything silly, but please let me know if any of my assumptions is wrong :
1. I take FBi's251's AOKP milestone 6 (ICS 4.0.4)
2. 8GB SDCard was formatted to FAT32 (4GB) and EXT3 (4GB) using TWRP kernel
(Beastmode's proton kernel to be exact).
3. I would flash this kernel and it would move apps and their data to the sd-ext
without any special additions.
Thanks. I read the thread, but unfortunately 8GB SD is what i have and I think it should be enough.
Thanks again.
P.S - it's for 2 guys I already sold them my SGS4Gs. I want them to be happy...
Click to expand...
Click to collapse
AOKP should be fine. I haven't tried it recently, but it was the tree in which I did the early Hefe Kernel development.
As I understand it, you have a microSD with
partition 1: 4 GB FAT32
partition 2: 4 GB ext3
So that can work, but will need some tweaking of the init-on-fs.sh script. I intentionally didn't use the second partition as so many scripts gobble that up as sd-ext and do who knows what to it.
My first preference would be to reformat the cards, perhaps:
6 GB FAT32
1 MB ext2/3/4 (Yes, 1 MB, a sliver, choice of ext2, ext3, ext4 up to you)
2 GB ext4
since then the script will work without modification and if they install a third-party script that uses the second partition, it won't corrupt their data.
If you were to keep the formatting the way that it is now, you'd need to edit the mount commands in the script to look something like:
Code:
/system/xbin/busybox umount /data
/system/xbin/busybox mount -t ext3 -o noatime /dev/block/mmcblk0p2 /data
(removing the sd-ext mount)
I'm not sure what your expectations are, but all that the kernel and that script will do is mount a different disk partition on /data -- you need to manually move the data over (or restore from something like Titanium Backup). There may be some trickery in renaming that could be used with TWRP backups to restore from data.yaffs2.win to the new /data partition, but I haven't tried that at all.

Hi Jeff
Thanks for your quick reply, and sorry again for not seeing the Q&A thread.
I think making it :
partition 1: 4 GB FAT32 (sdcard)
partition 2: 2 GB ext3 (sd-ext)
partition 3: 2 GB ext3 (data)
partition 4: 1 MB (spare)
would be better and handle data as well. don't you think ?
Would it be worth doing with a "Team" micro-SD card (class 6 I believe) ?
Thanks.

I haven't tried a Class 6 card, but my gut feeling is that it will be dicey. I didn't "commit" to using /data on microSD until I had tried it for several days using Titanium Backup's ability to move both apps and app data to the external card. I would try that first, especially as the phones in question aren't going to be in your hands (I consider you an expert user, able to manage things outside the UI with ease).
I've attached some testing I did a while ago with Transcend and SanDisk cards. When you look at them, realize that the speed scale changes between them. I have a feeling that the real "performance" on a device is going to be related to relatively small reads and writes, not the ability to stream video to the card. I also don't know much about the Team brand, but I found that even some well-known brands didn't have the performance of the Transcend or SanDisk in the same category.
However you configure your cards, I would definitely recommend a journaling filesystem of some sort. I've had my microSD come loose inside the phone. The journal will at least help to reduce any filesystem corruption should that happen.
You don't need the fourth partition -- I have it there to be able to keep rsync backups for fast ROM swapping.
.

Regarding the apps data, have you tried exploring the Mount2SD script ?
sent from me

I've tried a couple of the scripts out there in the past. Since backing up my data is very important to me, I trust the scripts in Titanium Backup to work well with its backup/restore strategies.
Mounts2SD looks like it has gotten a lot more sophisticated than it was when I tried it in the past. It sounds like something worth trying in its current state. At a quick glance (and not looking at the code), I'd personally make some different choices about features; enabling journaling, and being concerned about why lost+found was filling up (things should only appear there if the file system is found to be corrupt).