[Suggestion] mkfs.ext4 format instead of delete_recursive("/system") ? - Acer Iconia A500

Hey guys,
On some ROMs update scripts, I've been noticing that the ROMs delete from the system partition using a delete_recursive("/system") command instead of just bombing the system partition with a format. I was just suggesting that wouldn't it be a better idea to run a ext4 format on the /system partition, therefore you have a "clean slate" instead of deleting stuff from /system and leaving stuff behind in the ext4 journal?
The reason I say this is that if any blocks are actually bad, a delete won't reveal them. If you format the system partition using mkfs.ext4, it allows the system to do a quick scan for bad blocks and mark them before formatting, and finally copying files to the system partition.
One would just have to do something like this in their update-script:
Code:
run_program("/sbin/busybox","mkfs.ext4 -L system -m 0 <mtdblock of system partition>");
Again, this is only a suggestion. Feel free to argue!

Related

[Q] I/O Performance boost

Hy all!
I found a very interesting post over at samdroid.net
My question is its possible to port this mod for our hero?
Link:
http://forum.samdroid.net/f55/i-o-performance-boost-migrate-your-spica-ext2-2218/
Info:
What does it do?
Reformatting /data as ext4 (as it needs journaling for safety), and /system as ext2(as it is mounted ro all the time).
Thx for the answer.
Regards
Wenner
It gives performance boost on Samsung phones because Samsung has it's own filesystem which slows down whole system. Reformatting it to ext gives boost because ext is faster. HTC Android devices has ext partitions as default so it isn't needed.
Wrong, on all counts.
The storage partitions on the HTC Hero and other devices is nand memory, not a block device. ext filesystem is designed for block devices. The filesystems on /data /system /cache etc are all yaffs2, a filesystem designed specifically for Memory Technology Devices like the NAND in our phones.
Furthermore, even if you could format /data, /system etc as a filesystem other than yaffs2 you'd have to do it from outside the ROM, either via recovery or hboot somehow. A journalling filesystem is destructive to flash memory because flash memory has a finite number of writes before it fails. You'd also have to have a custom kernel if the default kernel doesn't support the filesystem you want to switch to.
If you use old style apps2sd and therefore have a partition for it on your sdcard, they're set up to emulate block devices and you should use ext2 for the reasons pointed out earlier. sdcards are still flash memory at heart and thus journalling is destructive.
Thanks for explanation, but i have question - why we don't use yaffs2 for app2sd (which is designed for flash memory)?
And which is faster - yaffs2 or ext2? On Samsung devices reformatting whole system to ext2 gives performance boost (in comparision to RFS).

CyanogenMOD 7 applications install issue

I have an issue on CM7. Is not actually an issue is just an anoying thing. Because datadata partition is only 170mb I can't install all of my apps. I know codeworkx s
aid they won't make the partirion bigger but I read somenthing on MIUI QA thread that involved deleting of data inside data folder and copy datdata instead. I tried that but all of my apps stopped working. Now I am curious if there is any other way to "expand" datadata partition. I'm waiting your opinions.
The suggestion isn't to delete the data inside the data folder.
if you look carefully at /data/data, you'll see it's merely a symoblic link to /datadata. Apparently, Android (or is it merely CM7?) expects to see the data inside /data/data. However, the /data partition is on a slower type of flash memory than /datadata, hence the idea to use a symbolic link here.
The suggestion above is to break the symbolic link (i.e. delete it) and copy the contents of /datadata to /data/data as a real subdirectory. This has the advantage of not limiting the size of your app data, but has the performance disadvantage of moving all app data to a slower partition.
What I figure is that I can do the following:
Code:
mkdir data/data_1
cd data/data_1
for i in /datadata/*
do ln -s $i .
done
cd /data
rm data
mv data_1 data
This does something similar to the original suggestion of copying /datadata over to the same partition as /data, but what it actually does is, it leaves the existing data on the faster partition, and puts new app data in the slower partition. If you find a certain app needs more performance, you can always move it to /datadata and put a link to it inside /data/data.

Any way to increase the /system partition in ICS??

Since when I have updated to official ICS I get now & then warning messages telling me there's not enough space left (i.e. 'ROM is full', '/system has not enough space left', etc., etc.) and this with the same apps installed as before and with plenty of room left in both the internal and external SD.
Running dp /system I get:
Code:
[email protected]:/ $ export PATH=/data/local/bin:$PATH
[email protected]:/ $ df /system
Filesystem 1K-blocks Used Available Use% Mounted on
/dev/block/mmcblk0p9 858724 857736 988 100% /system
ics is probably heavier on apps and system settings than gingerbread, if you have root access you can always remove some app that arent used to gain more space
I had an issue on GB where the media scanner was eating up ~1GB of the system partition. Force close and clear cache sorted it.
No idea if it could be the same issue for you but worth checking...
Maskell said:
I had an issue on GB where the media scanner was eating up ~1GB of the system partition. Force close and clear cache sorted it.
No idea if it could be the same issue for you but worth checking...
Click to expand...
Click to collapse
impossible, the system partition is only 1gb in size for the rom, unless you mean the 2gb data partition for apps
Yep, you're right. My bad

Help missing 13gb data - nexus 7

Okay so i was just doing a bit of file management. I removed a 1.4gb psp iso i had on my nexus 7 and then i checked how much space i had left using storage option in settings. I checked it and it said i had 25gb free when before i removed my file i had only 13gb free. Tried rebooting device and then used es file explorer to see all files. Opened es file explorer and then noticed everything was gone. Only stock items were folders were left eg Android, Download etc. All my msuic and some game data was gone. Opened up asphalt 7 to see if it would still work but it doesnt anymore. Tried opening real racing 3 And it asks me to redownload game data. My widgets are still in homescreen and work and some of the other apps i have still work as well eg plague inc, subway surfer and most of the other ones.
Any idea on how this happened and how i can recover my files? I have a bugsense file as well that was left on my device.
As to recovery of lost files your options are not good. (And if we're talking a non-rooted device, the odds are approximately equal to 0%) Recovery in ext4 filesystems is technically much more challenging than in simple filesystems such as FAT. And this pessimistic outlook presumes that the filesystem is healthy/clean. If the reason for the problem occurring in the first place was a corrupted filesystem, then the odds go from simply bad to pathetically poor.
Sorry, dude... got any Nandroid or TiBu backups stored on your PC?
If you had Putin's top-secret files on your N7 and the CIA got hold of it, the first thing a forensic analyst would do is try to take a raw (block) device dump off of the "cold" device. (If you are still running the N7 with the regular OS the /data partition is being continually written to, and this further reduces the chances of file recovery every second the device is booted).
In the case of an analyst with less resources, this might mean using a custom recovery boot to get the raw device copy; unfortunately, the /data partition is huge - nearly 30 GB - so you would have to mount a extN filesystem via OTG... and doing so thus precludes using adb, so you would need to use a recovery with a touch interface and command-line entry (e.g. TWRP)
# mkdir /mnt/myOTGdisk
# mount -t ext2 -o rw /dev/sda1 /mnt/myOTGdisk/
# dd bs=8196 if=/dev/block/platform/sdhci-tegra.3/by-name/UDA of=/mnt/myOTGdisk/userdata.img
Doing such a thing would allow you to examine that huge image file with forensic file recovery tools from a PC (probably running Linux) as in principle you captured the entire ext4 filesystem.
The thing is, efforts spent in file recovery should be proportional to the value of the files being recovered. I'm not sure if your saved gaming history rises to that occasion. For sure the dude at the CIA won't want to help you with that.
As to the source of your troubles, it's hard to say. With TWRP booted, you can run the "e2fsck" program to see if the /data ext4 filesystem is corrupted, e.g.
# mount | grep /data ( see which mmcblk0 partition is /data, on grouper it is mmcblk0p9 )
# umount /sdcard
# umount /data
# e2fsck -f -n /dev/block/platform/sdhci-tegra.3/by-name/UDA
(For the last command above, you might need to use the block device name /dev/block/mmcblk0p?? instead of the UDA symlink )
If the above command shows that you have a corrupted /data filesystem, I would re-initialize that filesystem ( "fastboot format userdata" ) - note this wipes all userdata including the psuedo-SD card.
Finally, I should point out that some type of hardware failure might have occurred somewhere in that huge 30 GB partition - if that is the case then there will be problems down the road again. If that is the case, the only way to detect this will be a write test which nearly fills that partition, followed by a filesystem sanity check as shown above.
Probably that would need to be done in the recovery rather than in the normal OS, as a nearly full /data filesystem will probably wedge the device.
Phew, I've said enough.
Good luck
I never tire of reading your posts, bftb0, ("...the odds are approximately equal to 0%")...genius.
But don't the CIA have access to Cray, 'Kasparov' DeepBlue beating SuperComputers that could make mincemeat out of the kind of thing your alluding to... in less time than it takes to flash a ROM... or have I been watching too many James Bond movies?
Vaguely rhetorical question - think I already know the answer...
Still... what a great post.
Rgrds,
Ged.
---------- Post added at 01:22 AM ---------- Previous post was at 12:50 AM ----------
Hi, leont1280...
You could try running this ...
Disk Usage - http://play.google.com/store/apps/details?id=com.google.android.diskusage&hl=en
It gives a graphical 'map' or overview of your storage, and you can visually see where everything is (or should be), great for tracking down missing stuff... but as bftb0 has mentioned, it doesn't look promising.
Rgrds,
Ged.
Use astro file manager u can check it out
Sent from my Nexus 7 using Tapatalk 2
Right bftb0 i did what you said in twrp and i recieved the following summary information.
/dev/block/mmcblk0p10: 28133/1835008 files (3.2% non-contiguous) , 1571673/733977
Any idea on what that means?
Also under the mount option in Twrp i can Unmount and mount the System, Data and its Cache. However i cant Mount the SD Card. Should that be a concern?
bftb0 said:
As to recovery of lost files your options are not good. (And if we're talking a non-rooted device, the odds are approximately equal to 0%) Recovery in ext4 filesystems is technically much more challenging than in simple filesystems such as FAT. And this pessimistic outlook presumes that the filesystem is healthy/clean. If the reason for the problem occurring in the first place was a corrupted filesystem, then the odds go from simply bad to pathetically poor.
Sorry, dude... got any Nandroid or TiBu backups stored on your PC?
If you had Putin's top-secret files on your N7 and the CIA got hold of it, the first thing a forensic analyst would do is try to take a raw (block) device dump off of the "cold" device. (If you are still running the N7 with the regular OS the /data partition is being continually written to, and this further reduces the chances of file recovery every second the device is booted).
In the case of an analyst with less resources, this might mean using a custom recovery boot to get the raw device copy; unfortunately, the /data partition is huge - nearly 30 GB - so you would have to mount a extN filesystem via OTG... and doing so thus precludes using adb, so you would need to use a recovery with a touch interface and command-line entry (e.g. TWRP)
# mkdir /mnt/myOTGdisk
# mount -t ext2 -o rw /dev/sda1 /mnt/myOTGdisk/
# dd bs=8196 if=/dev/block/platform/sdhci-tegra.3/by-name/UDA of=/mnt/myOTGdisk/userdata.img
Doing such a thing would allow you to examine that huge image file with forensic file recovery tools from a PC (probably running Linux) as in principle you captured the entire ext4 filesystem.
The thing is, efforts spent in file recovery should be proportional to the value of the files being recovered. I'm not sure if your saved gaming history rises to that occasion. For sure the dude at the CIA won't want to help you with that.
As to the source of your troubles, it's hard to say. With TWRP booted, you can run the "e2fsck" program to see if the /data ext4 filesystem is corrupted, e.g.
# mount | grep /data ( see which mmcblk0 partition is /data, on grouper it is mmcblk0p9 )
# umount /sdcard
# umount /data
# e2fsck -f -n /dev/block/platform/sdhci-tegra.3/by-name/UDA
(For the last command above, you might need to use the block device name /dev/block/mmcblk0p?? instead of the UDA symlink )
If the above command shows that you have a corrupted /data filesystem, I would re-initialize that filesystem ( "fastboot format userdata" ) - note this wipes all userdata including the psuedo-SD card.
Finally, I should point out that some type of hardware failure might have occurred somewhere in that huge 30 GB partition - if that is the case then there will be problems down the road again. If that is the case, the only way to detect this will be a write test which nearly fills that partition, followed by a filesystem sanity check as shown above.
Probably that would need to be done in the recovery rather than in the normal OS, as a nearly full /data filesystem will probably wedge the device.
Phew, I've said enough.
Good luck
Click to expand...
Click to collapse
Right bftb0 i did what you said in twrp and i recieved the following summary information.
/dev/block/mmcblk0p10: 28133/1835008 files (3.2% non-contiguous) , 1571673/733977
Any idea on what that means?
Also under the mount option in Twrp i can Unmount and mount the System, Data and its Cache. However i cant Mount the SD Card. Should that be a concern?
leont1280 said:
Right bftb0 i did what you said in twrp and i recieved the following summary information.
/dev/block/mmcblk0p10: 28133/1835008 files (3.2% non-contiguous) , 1571673/733977
Click to expand...
Click to collapse
Hmmm, mmcblk0p10 - you must have a tilapia (3G N7) device, yes?
If you had any filesystem errors, that e2fsck run would have produced copious reams of output. If a filesystem is clean, it produces only 5 or 6 lines of summary output.
leont1280 said:
Any idea on what that means?
Also under the mount option in Twrp i can Unmount and mount the System, Data and its Cache. However i cant Mount the SD Card. Should that be a concern?
Click to expand...
Click to collapse
I've seen the same business with TWRP and the /sdcard mount - I wouldn't worry about it. (It is not a "normal" mount in the sense of extN or FAT device partition mount - it behaves sort of like a strange symlink where the target directory and descendants all appear to have different file ownership and permissions than what exist in the true (underlying) filesystem. No doubt this is all performed in the kernel... I don't know whether a command-line invocation of "mount" can create this mount point, or whether a specific syscall/ ioctl is needed)
But back to your N7 - the lack of any errors in the filesystem check is good news, but also suggests that your files didn't disappear through a hardware failure. Are you sure you didn't fat-finger things when using the file manager? (I suppose it is possible that the file manager has a bug...)
I didn't look into what tools are available for extN forensic/recovery work. I can guess that the effort would be non-trivial, though.
bftb0 said:
Hmmm, mmcblk0p10 - you must have a tilapia (3G N7) device, yes?
If you had any filesystem errors, that e2fsck run would have produced copious reams of output. If a filesystem is clean, it produces only 5 or 6 lines of summary output.
I've seen the same business with TWRP and the /sdcard mount - I wouldn't worry about it. (It is not a "normal" mount in the sense of extN or FAT device partition mount - it behaves sort of like a strange symlink where the target directory and descendants all appear to have different file ownership and permissions than what exist in the true (underlying) filesystem. No doubt this is all performed in the kernel... I don't know whether a command-line invocation of "mount" can create this mount point, or whether a specific syscall/ ioctl is needed)
But back to your N7 - the lack of any errors in the filesystem check is good news, but also suggests that your files didn't disappear through a hardware failure. Are you sure you didn't fat-finger things when using the file manager? (I suppose it is possible that the file manager has a bug...)
I didn't look into what tools are available for extN forensic/recovery work. I can guess that the effort would be non-trivial, though.
Click to expand...
Click to collapse
Im pretty sure i didnt accidently delete it myself. When i was doing file management i was using my laptop with the N7 3g connected to it via MTP. Once i deleted the iso file the N7 started acting strange. I did notice a bit of lag that was usually out lf the ordinary and when i checked available space left it increased to 25gb rather than saying 13gb
aaah, having the same problem here, i was cleaning my n7 using my laptop, found a strange folder on my sd card, looked inside and it has a back up of some of my deleted files! interesting! i deleted the folder, then i started cheking other folders, like my ebooks, audio books and etc, but all my folders were empty!
so i disconnected my tablet, and after reconnecting, bam, all files gone.

Moving on to F2FS

My Idea is to change the Filesystem on my d802.
Via adb I pulled the whole /data/media partion so that I can Push it back later.
I am not really Sure how this will work with the System partition.
I believe that flashing a cloudy G3 rom will Format the System partition back to ext4 (i think it's in the install Script).
So Would it be possible that I remove that "formating System" line to keep f2fs. Any other thoughts on this?

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