On Sat, Jan 11, 2014 at 06:10:35PM +0100, MegaBrutal wrote: > 2014/1/11 Hugo Mills <hugo@xxxxxxxxxxxxx>: > > > > [60631.481913] attempt to access beyond end of device > > [60631.481935] dm-1: rw=1073, want=42917896, limit=42917888 > > [60631.481941] btrfs_dev_stat_print_on_error: 34 callbacks suppressed > > [60631.481949] btrfs: bdev /dev/mapper/vmhost--vg-vmhost--rootfs errs: wr 311347, rd 0, flush 0, corrupt 0, gen 0 > > > > This is the problem. > > > > It looks like you've shrunk the LV without first shrinking the > > filesystem. Depending on how much you shrunk it by, the odds are > > fairly good that significant chunks of the FS are now toast. > > > > Hugo. > > > > Thank you very much! Strange, I indeed shrinked the LV, but only by a > few megabytes to make space for /boot (as turned out, GRUB2 can't boot > from LVM), and I think I did shrink the FS too... But maybe not. As it > started out as a test system, I intentionally wanted to test some > obscure situations here. Thankfully I don't have considerable data > loss and I don't think any valuable data was on the space that was cut > off. Strange that the system was running like this for a month with > this problem being undetected. > > How can I shrink the FS to the correct size right now, ensuring that I > really shrink it to the exact LV size? In the current state, I'm not sure that you can -- the FS metadata still thinks that there's some data stored at an address that's off the end of the LV, and it'll try to read it if you attempt to shrink the FS. You may be able to enlarge the LV up to the size it was before, and then shrink, but you'll probably get EIO from the filesystem because the checksums for the (un)dead area don't match any more (assuming that the data in question has been overwritten by something else in the mean time). I suspect that we need some kind of "yes, I know the data's buggered, but carry on regardless" option for a lot of commands, like resize(shrink), device delete, device replace. This would help in the case where a lo-fi recovery is acceptable. Hugo. -- === Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk === PGP key: 65E74AC0 from wwwkeys.eu.pgp.net or http://www.carfax.org.uk --- "Your problem is that you have a negative personality." --- "No, I don't!"
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