Re: csum errors in VirtualBox VDI files

[Kai Krakow <hurikhan77@gmail.com>]

Am Tue, 22 Mar 2016 09:03:42 +0100
schrieb Kai Krakow <hurikhan77@gmail.com>:

> Hello!
> 
> Since one of the last kernel updates (I don't know which exactly), I'm
> experiencing csum errors within VDI files when running VirtualBox. A
> side effect of this is, as soon as dmesg shows these errors, commands
> like "du" and "df" hang until reboot.
> 
> I've now restored the file from backup but it happens over and over
> again.
> 
> On another machine I'm also seeing errors with big files in the
> following scenario (apparently an older kernel, 4.1.x I afair):
> 
> # ntfsclone --save /dev/md126p2 -o rescue.ntfs.img
>                    ^ big NTFS partition   ^ file on btrfs
> 
> results in a write error and the file system goes read-only.
> 
> Both systems have in common they are using btrfs on bcache with
> compress=lzo,autodefrag,nossd,discard (mraid=1,draid=0 and
> mraid=1,draid=single).
> 
> The system mentioned first is running Kernel 4.5.0 with Gentoo
> patch-set. I upgraded from the last 4.4.x kernel when I first
> experienced this problem. The first time the problem resulted in a
> duplicate extent which btrfsck wasn't able to fix, that's when I first
> restored from backup. But now I'm getting csum errors in this file
> over a over again, plus when rsync has run for backup, the system no
> longer responds to "du" and "df" commands - it just hangs.
> 
> Known problem? Does it help if I send debug info? If so, please
> instruct.

Interestingly, ddrescue just skips over these csum errors without
counting an error...


-- 
Regards,
Kai

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