[linux-lvm] Filesystem corruption with LVM's pvmove onto a PV with a larger physical block size

[Ingo Franzki]

On 28.02.2019 15:36, Ilia Zykov wrote:
>> Discarding device blocks: done
>> Creating filesystem with 307200 1k blocks and 76912 inodes
>> ......
>> # 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.
>>
> 
> It's because you FS had 1k blocks.
> New device can't read with block 1k.
> If you plan pvmove on device with 4k. Maybe you need make fs with:
> "mkfs.ext4 -b 40
The beauty of pvmove is that it works on existing LVs with filesystems on it.
So I might have filesystems on LVs that used the default block size that I want to move via pvmove.
At the time the file system was created (possibly may years ago), I did not know that I would ever move it to a device with a larger block size.
If I have to create a new filesystem after the move, then pvmove is useless.... I then could just create a new LV on the desired PV(s). 
> 
> See comments:
> https://bugzilla.redhat.com/show_bug.cgi?id=1684078
> 


-- 
Ingo Franzki
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