Hacking SD card file system - Page 4

davidfor · 08-05-2016, 10:35 AM

Quote:

Originally Posted by rtiangha

That said, I wonder if it's possible to modify frostschutz's dosfsck script to either probe the partition to figure out what it's formatted with and run the proper utility, or to run e2fsck instead if dosfsck fails, so that way, it wouldn't matter to the device what file system that partition is formatted in (let the Kobo assume it's still FAT32) and will run the disk check whenever it needs to run a disk check under normal operations. Seems kind of silly to have a journaled file system if the device won't file check it every so often (assuming Kobo hard coded it to do that to the FAT32 partition once in a while), although to be fair, I don't know under what circumstances the Kobo would call dosfsck in the first place. Hopefully it would do it on regular intervals or whenever it detects issues with the file system.

Every time the device boots, the firmware runs:

Code:

dosfsck -a -w /dev/mmcblk0p3

And if it finds the file system is corrupt, it will prompt you to do a factory reset.

frostschutz · 08-05-2016, 10:42 AM

Kobo runs dos-fsck whenever you pull the USB plug. Also possibly on bootup. If the user partition is found to be corrupt it will factory reset. For the system partition, if I remember correctly there isn't even a fsck for ext4 included so it completely relies on journaling to fix things here. You could fsck it while it's connected to your PC. Or include a fsck binary with this mod...

Problems with Calibre are to be expected; Calibre has a certain set of rules it uses to identify devices, it probably doesn't like deviations too much (things also stop working after firmware updates), so... and I don't allow my Calibre to mount stuff anyhow so I can't test for these things either.

rtiangha · 08-05-2016, 11:57 AM

Calibre works fine once you change permissions to allow you to write to the partition and mount it before launching Calibre. I copied a couple of books after the ext4 conversion, compressed the database, etc and things work fine.

Ah, I guess the fast boot up then is less because of the file system change and more because it does no disk check at all. The increase in file transfer speed between it and Ubuntu is no mistake though. I might try copying an e2fsck binary over; I assume this thing uses an ARM CPU? I'm not sure how I'd test things though; I haven't yet installed ssh on this thing yet so I'd have to either pull the SD card out or flash changes each time which would get annoying.

Sent from my GT-N5110 using Tapatalk

JSWolf · 08-05-2016, 02:42 PM

Quote:

Originally Posted by davidfor

Every time the device boots, the firmware runs:

Code:

dosfsck -a -w /dev/mmcblk0p3

And if it finds the file system is corrupt, it will prompt you to do a factory reset.

If we reformat in order to use the Win 10AU, will this cause a problem?

rtiangha · 08-05-2016, 03:24 PM

Theoretically, it shouldn't. Then again, mkfs.vfat shouldn't create a nonstandard FAT32 partition, but according to that Windows 10 thread, it seems that it does, so who knows? If it's running dosfsck on boot and whenever you disconnect your Kobo from your PC and you did the reformat using that partition program and things are still working fine for you using the Windows 10 Anniversary Update, then I suppose everything is fine.

Sent from my GT-N5110 using Tapatalk

JSWolf · 08-05-2016, 03:35 PM

Quote:

Originally Posted by rtiangha

Theoretically, it shouldn't. Then again, mkfs.vfat shouldn't create a nonstandard FAT32 partition, but according to that Windows 10 thread, it seems that it does, so who knows? If it's running dosfsck on boot and whenever you disconnect your Kobo from your PC and you did the reformat using that partition program and things are still working fine for you using the Windows 10 Anniversary Update, then I suppose everything is fine.

Sent from my GT-N5110 using Tapatalk

It turns out that the problem that was posted about was because the partition was formatted using exFAT and not FAT32. That's why it failed.

davidfor · 08-05-2016, 09:01 PM

Quote:

Originally Posted by frostschutz

Problems with Calibre are to be expected; Calibre has a certain set of rules it uses to identify devices, it probably doesn't like deviations too much (things also stop working after firmware updates), so... and I don't allow my Calibre to mount stuff anyhow so I can't test for these things either.

The file system doesn't matter to calibre. It is identifying the devices based on ids and that they are mounted. The driver is then looking for the database and the version file.

Ken Maltby · 08-05-2016, 09:17 PM

calibre even will see, and work with KOReader as a device. The same for "Calibre Companion" on Android devices.

Luck;
Ken

flowoeB · 08-09-2016, 09:21 AM

hi,
just wanted to tell you that I successfully changed the internal card of my glow hd to a 32 GB all partitions ext3 formated sd card following frostschutz' tutorial. did it on my mac - had to take out the sd card for formating. I used ExtFs for Mac by Paragon for formating and accessing the card - paragon is slow as hell but does the job.

the reader runs perfectly smooth afterwards. like it!

thx frostschutz!

btw: has anybody tried a 200GB MicroSD Card yet?

maranium · 09-18-2016, 05:35 AM

When I finally got around to it, and after a test run on a small capacity card, I was able to use frostschutz's patch on my 128GB card, back it up, convert it to ext2, and then restore my library. And it did exactly what I needed, which was to be able to keep generating book covers, without the fat32 file limit. It did run kinda slowly at first, but oddly enough seems to be better now. Maybe a bit slower then before, but small price to pay to continue to stay on an old firmware, and still browse the full library without half of it not displaying covers.

davidfor · 09-18-2016, 06:54 AM

Quote:

Originally Posted by maranium

When I finally got around to it, and after a test run on a small capacity card, I was able to use frostschutz's patch on my 128GB card, back it up, convert it to ext2, and then restore my library. And it did exactly what I needed, which was to be able to keep generating book covers, without the fat32 file limit. It did run kinda slowly at first, but oddly enough seems to be better now. Maybe a bit slower then before, but small price to pay to continue to stay on an old firmware, and still browse the full library without half of it not displaying covers.

What firmware version are you running? The way the firmware stores cover images changed a long time ago. The number of files problem went away at that time.

bunbury · 08-22-2020, 07:46 PM

Hello
I tried this on my Clara HD with the latest firmware.
It boots ok, see the correct amount of free space in the device information page.
But when I connect it via usb; the KOBOeReader partition is not accessible from my Ubuntu Linux.
Any idea what's going on ?

08-09-2016, 09:21 AM	#54
flowoeB E-Reader Sammler Posts: 143 Karma: 4160 Join Date: Feb 2009 Location: Austria Device: plenty...	hi, just wanted to tell you that I successfully changed the internal card of my glow hd to a 32 GB all partitions ext3 formated sd card following frostschutz' tutorial. did it on my mac - had to take out the sd card for formating. I used ExtFs for Mac by Paragon for formating and accessing the card - paragon is slow as hell but does the job. the reader runs perfectly smooth afterwards. like it! thx frostschutz! btw: has anybody tried a 200GB MicroSD Card yet? Last edited by flowoeB; 08-09-2016 at 09:43 AM.

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08-05-2016, 10:42 AM	#47
frostschutz Linux User Posts: 2,282 Karma: 6123806 Join Date: Sep 2010 Location: Heidelberg, Germany Device: none	Kobo runs dos-fsck whenever you pull the USB plug. Also possibly on bootup. If the user partition is found to be corrupt it will factory reset. For the system partition, if I remember correctly there isn't even a fsck for ext4 included so it completely relies on journaling to fix things here. You could fsck it while it's connected to your PC. Or include a fsck binary with this mod... Problems with Calibre are to be expected; Calibre has a certain set of rules it uses to identify devices, it probably doesn't like deviations too much (things also stop working after firmware updates), so... and I don't allow my Calibre to mount stuff anyhow so I can't test for these things either.

08-05-2016, 11:57 AM	#48
rtiangha Evangelist Posts: 495 Karma: 356531 Join Date: Jul 2016 Location: 'burta, Canada Device: Kobo Glo HD	Calibre works fine once you change permissions to allow you to write to the partition and mount it before launching Calibre. I copied a couple of books after the ext4 conversion, compressed the database, etc and things work fine. Ah, I guess the fast boot up then is less because of the file system change and more because it does no disk check at all. The increase in file transfer speed between it and Ubuntu is no mistake though. I might try copying an e2fsck binary over; I assume this thing uses an ARM CPU? I'm not sure how I'd test things though; I haven't yet installed ssh on this thing yet so I'd have to either pull the SD card out or flash changes each time which would get annoying. Sent from my GT-N5110 using Tapatalk

08-05-2016, 03:24 PM	#50
rtiangha Evangelist Posts: 495 Karma: 356531 Join Date: Jul 2016 Location: 'burta, Canada Device: Kobo Glo HD	Theoretically, it shouldn't. Then again, mkfs.vfat shouldn't create a nonstandard FAT32 partition, but according to that Windows 10 thread, it seems that it does, so who knows? If it's running dosfsck on boot and whenever you disconnect your Kobo from your PC and you did the reformat using that partition program and things are still working fine for you using the Windows 10 Anniversary Update, then I suppose everything is fine. Sent from my GT-N5110 using Tapatalk

08-05-2016, 09:17 PM	#53
Ken Maltby Wizard Posts: 4,466 Karma: 6900052 Join Date: Dec 2009 Location: The Heart of Texas Device: Boox Note2, AuraHD, PDA,	calibre even will see, and work with KOReader as a device. The same for "Calibre Companion" on Android devices. Luck; Ken

09-18-2016, 05:35 AM	#55
maranium Member Posts: 14 Karma: 10 Join Date: Jan 2012 Device: Kobo Touch, Glo, Mini	When I finally got around to it, and after a test run on a small capacity card, I was able to use frostschutz's patch on my 128GB card, back it up, convert it to ext2, and then restore my library. And it did exactly what I needed, which was to be able to keep generating book covers, without the fat32 file limit. It did run kinda slowly at first, but oddly enough seems to be better now. Maybe a bit slower then before, but small price to pay to continue to stay on an old firmware, and still browse the full library without half of it not displaying covers.

08-22-2020, 07:46 PM	#57
bunbury Enthusiast Posts: 37 Karma: 100 Join Date: Jan 2015 Location: Paris, France Device: Kobo Clara HD	Hello I tried this on my Clara HD with the latest firmware. It boots ok, see the correct amount of free space in the device information page. But when I connect it via usb; the KOBOeReader partition is not accessible from my Ubuntu Linux. Any idea what's going on ?