Am Donnerstag, 10. Dezember 2009 schrieb Willie Wong: > > I use FAT32 on my external HDDs to make it easier to share with other > > people and OSes. Never had a problem before, but now I do. Lately, when I > > save videos to my disks, and play them back after the file system cache > > is emptied, they have completely different content (of files that are > > long deleted). > > Please describe in more detail what you actually did. Did you > read/write the files in linux? Both under 2.6.31? A step-by-step maybe > appreciated.
Yes, of course, see below. > > I just had the magnificent idea to look into the syslog and found loads > > of "kernel: bio too big device sdb (248 > 240)" > > > > I heard romours of problems with the current FAT implementation due to > > M$. I went back to 2.6.30 for the moment. So what???s your proposal? > > Usually I don???t have the need for ??bercurrent kernels, but would > > installing 2.6.32 help? > > Did you file a bug? Where did you hear this "rumour"? I believe heise.de, the publisher of computer magazine c't. I just looked for it - it was about Microsoft pursuing legal actions against TomTom for using their FAT file system on their linux based devices. I deduced from that that they rewrote the FAT driver, but this would seem rather unlikely. > You are not running any sort of LVM, RAID, or encryption, are you? > A similar bug seems to have occured in device mapper, where dm gave > the underlying fs the wrong values for max_hw_sector. I reckon that's more like it - all my external hard drives are truecrypted. Here's what I did yesterday to verify my theory: First I booted into the correctly working 2.6.30 and mounted my external HDD. Then I copied a 700 MB and a 1400 MB video file to the disk. Then I unmounted the drive to clear the file system cache and remounted - the videos were fine. Then I rebooted into 2.6.31 and copied the same files again (I didn't delete the ones from the first test). Unmounted and remounted the drive. The files from the first run were still OK, but those from the second test showed the wrong content (as mentioned, either mplayer showed the content of a long deleted file, or nothing at all, 'file' just recognised it as "data"). > I am somehow more leaning toward the problem being in the usb > subsystem. > > When you plug-in your device, what does > /sys/block/sdb/queue/max_hw_sectors_kb say? I'm in 2.6.30 ATM, I'll do it the next time I boot the machine. -- Gruß | Greetings | Qapla' begin signature_virus Hi! I’m a signature virus. Please copy me to your signature to help me spread. end
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