Re: Filesystem corruption with LVM's pvmove onto an encrypted volume with LUKS2 and a sector size of 4096
Ingo Franzki <[email protected]>
| Newsgroups | gmane.linux.kernel.device-mapper.dm-crypt |
|---|---|
| Message-ID | <[email protected]> |
On 21.02.2019 14:02, Arno Wagner wrote: > Hi, > > LUKS should still be using 512 Byte sectors. Any mismatch > there should just impact performance, Yes, LUKS(1) uses 512 and it does not show the problem, but LUKS2 supports larger sector sizes and it causes the problem if used. > > I suspect you have an offset problem and the sector-numbers > (used as initialization for each secor's encryption) are > shifted, expecially if this happens in plain mode as well. Quite possible. Therefore I suspect a problem in dm-crypt and/or LVM. > > Regards, > Arno > > On Thu, Feb 21, 2019 at 13:03:51 CET, Ingo Franzki wrote: >> Hi, >> >> we just encountered an error when using LVM's pvmove command to move the data from an un-encrypted LVM physical volume onto an encrypted volume. >> After the pvmove has completed, the file system on the logical volume that resides on the moved physical volumes is corrupted. >> >> It seems to be related to a sector size of 4096 used with LUKS2. Once I use the default sector size (512) then the problem does not happen. >> It happens with LUKS2 and even plain mode, as soon as a sector size of 4096 is used. LUKS1 and the default sector size does not show the problem. >> >> Not sure if this is a problem in dm-crypt or LVM, or a combination of both. >> >> Here is how to reproduce (note the error messages on the very last command): >> >> # sudo dd if=/dev/zero of=loopbackfile1.img bs=500M count=1 >> 1+0 records in >> 1+0 records out >> 524288000 bytes (524 MB, 500 MiB) copied, 2.32777 s, 225 MB/s >> >> # sudo dd if=/dev/zero of=loopbackfile2.img bs=500M count=1 >> 1+0 records in >> 1+0 records out >> 524288000 bytes (524 MB, 500 MiB) copied, 1.89992 s, 276 MB/s >> >> # losetup -fP /root/loopbackfile1.img >> >> # losetup -fP /root/loopbackfile2.img >> >> # pvcreate /dev/loop0 >> Physical volume "/dev/loop0" successfully created. >> >> # vgcreate LOOP_VG /dev/loop0 >> Volume group "LOOP_VG" successfully created >> >> # lvcreate -L 300MB LOOP_VG -n LV /dev/loop0 >> Logical volume "LV" created. >> >> # mkfs.ext4 /dev/mapper/LOOP_VG-LV >> mke2fs 1.44.1 (24-Mar-2018) >> Discarding device blocks: done >> Creating filesystem with 307200 1k blocks and 76912 inodes >> Filesystem UUID: 344289a3-e251-4d88-b03d-a71a4be2a8ec >> Superblock backups stored on blocks: >> 8193, 24577, 40961, 57345, 73729, 204801, 221185 >> >> Allocating group tables: done >> Writing inode tables: done >> Creating journal (8192 blocks): done >> Writing superblocks and filesystem accounting information: done >> >> # mount /dev/mapper/LOOP_VG-LV /mnt >> >> # cryptsetup luksFormat --type luks2 --sector-size 4096 /dev/loop1 >> >> WARNING! >> ======== >> This will overwrite data on /dev/loop1 irrevocably. >> >> Are you sure? (Type uppercase yes): YES >> Enter passphrase for /dev/loop1: loop >> Verify passphrase: loop >> >> # cryptsetup luksOpen /dev/loop1 enc-loop >> Enter passphrase for /dev/loop1: loop >> >> # pvcreate /dev/mapper/enc-loop >> Physical volume "/dev/mapper/enc-loop" successfully created. >> >> # vgextend LOOP_VG /dev/mapper/enc-loop >> Volume group "LOOP_VG" successfully extended >> >> # pvs >> PV VG Fmt Attr PSize PFree >> /dev/loop0 LOOP_VG lvm2 a-- 496.00m 196.00m >> /dev/mapper/enc-loop LOOP_VG lvm2 a-- 492.00m 492.00m >> >> # pvmove /dev/loop0 /dev/mapper/enc-loop >> /dev/loop0: Moved: 30.67% >> /dev/loop0: Moved: 100.00% >> >> # pvs >> /dev/LOOP_VG/LV: read failed after 0 of 1024 at 0: Invalid argument >> /dev/LOOP_VG/LV: read failed after 0 of 1024 at 314507264: Invalid argument >> /dev/LOOP_VG/LV: read failed after 0 of 1024 at 314564608: Invalid argument >> /dev/LOOP_VG/LV: read failed after 0 of 1024 at 4096: Invalid argument >> PV VG Fmt Attr PSize PFree >> /dev/loop0 LOOP_VG lvm2 a-- 496.00m 496.00m >> /dev/mapper/enc-loop LOOP_VG lvm2 a-- 492.00m 192.00m >> >> In case the filesystem of the logical volume is not mounted at the time of pvmove, it gets corrupted anyway, but you only see errors when trying to mount it. >> >> -- >> Ingo Franzki >> eMail: [email protected] >> Tel: ++49 (0)7031-16-4648 >> Fax: ++49 (0)7031-16-3456 >> Linux on IBM Z Development, Schoenaicher Str. 220, 71032 Boeblingen, Germany >> >> IBM Deutschland Research & Development GmbH / Vorsitzender des Aufsichtsrats: Matthias Hartmann >> Geschäftsführung: Dirk Wittkopp >> Sitz der Gesellschaft: Böblingen / Registergericht: Amtsgericht Stuttgart, HRB 243294 >> IBM DATA Privacy Statement: https://www.ibm.com/privacy/us/en/ >> >> _______________________________________________ >> dm-crypt mailing list >> [email protected] >> https://www.saout.de/mailman/listinfo/dm-crypt > -- Ingo Franzki eMail: [email protected] Tel: ++49 (0)7031-16-4648 Fax: ++49 (0)7031-16-3456 Linux on IBM Z Development, Schoenaicher Str. 220, 71032 Boeblingen, Germany IBM Deutschland Research & Development GmbH / Vorsitzender des Aufsichtsrats: Matthias Hartmann Geschäftsführung: Dirk Wittkopp Sitz der Gesellschaft: Böblingen / Registergericht: Amtsgericht Stuttgart, HRB 243294 IBM DATA Privacy Statement: https://www.ibm.com/privacy/us/en/ _______________________________________________ dm-crypt mailing list [email protected] https://www.saout.de/mailman/listinfo/dm-crypt