Re: systemd "journalctl" is 1.89sec on ext4, 1.49 min on btrfs

["Szőts Ákos" <szotsaki@gmail.com>]

Thank you very much for you suggestions!

I ran `filefrag` on /var/log/journal/ and the most fragmented files were:
/var/log/journal/[...]/faa9e41c6.journal: 11136 extents found
/var/log/journal/[...]/e9f8e1346c.journal: 633 extents found
/var/log/journal/[...]/59ec50b631.journal: 3585 extents found
/var/log/journal/[...]/59ec51d1b4.journal: 710 extents found
/var/log/journal/[...]/f74afadee9.journal: 484 extents found

Then I ran `btrfs fi defrag -v -f -clzo *` in the aforementioned directory 
three times and restarted the machine. Now, the `journalctl -b --no-pager` 
command runs in less than two seconds.

I tried to further optimize my file system (MySQL big storage files are highly 
affected), but somewhere (for me it looks like, on random places) there are 
kernel errors, so I suspended the further defragmentation until those errors 
are tracked down.

Thank you very much again.

Ákos