I'm quite sure it didn't happen before I started using LUKS and LVM on my disk (2 or 3 weeks ago), but now root user is constantly (every 2-3 seconds) writing (not reading, just writing) on disk and I can't figure out why.
The disk has one LUKS partition with one LVM group, which contains both root (ext4) and home (ext4) logical partitions (besides the swap one).
I've used "iotop" command to check what processes are accessing the disk and I've seen it's "jbd2/dm-X-8", executed by root, the process which is writing constantly to the disk.
It only happens with the disk containing the LVM; I have two more ext4 disks mounted (just for storage purposes; they also use LUKS encryption but not LVM) and they "stay quite" while no file operations are made on them.
I've checked log files to see if this writing activity could be due to some kind of logging, but it doesn't seem to be the case.
I've also read questions like this one:
But I can't understand why would the system keep on writing the disk even when no changes are being made to it.
On the other hand, I've had some issues with the disk which I though that could be related to other programs crashes, but now I don't know whether it could be related to this constant writing to disk, so I'm quite worried about it.
Is it normal? Can I do something to avoid it or is it something that just "comes with" LUKS/LVM? Or maybe it has nothing to do with LUKS/LVM and I should check some other thing?