On Sat, Jul 4, 2020 at 12:53 PM Randy Barlow <bowlofeggs@xxxxxxxxxxxxxxxxx> wrote: > > On 7/3/20 12:41 PM, Chris Murphy wrote: > > # rm -rf/var/lib/mysql/ > > > >> # mv/var/lib/mysql2/ /var/lib/mysql/ > >> ## resume operation > > BTW this should be proofread/sanity checked, especially because > > there's an rm command (that will fail in the original). > > You also might need a restorecon after this, since /var/lib/mysql2 seems > like it would be unlikely to get the right selinux contexts on the > files. I didn't test to verify that though, just a suggestion of > something to watch out for. Yep, this is likely, thanks for mentioning it. Either chcon in advance of the copy; or restorecon on this path after the rename. Another I thought of is to just copy to /tmp, remove the database files from /var/lib/mysql/, chattr +C /var/lib/mysql/, then copy the files back. *BUT* that is not crash safe, obviously. The main thing is that +C does inherit, but can only be applied to new files. Also there is a recent Phoronix set of benchmarks out for file systems on kernel 5.8, that's another lovely head scratcher. But it might (key word might) call into question whether we always want chattr +C on databases on Btrfs. I know very little about databases so this might be something a few interested folks explore patiently to figure out. For all I know there are some databases (and the actual workload for a specific instance) that work fine or even better leaving it as datacow; it might even be true some databases are significantly compressible in a way that has an advantage. And nodatacow means no compression. -- Chris Murphy _______________________________________________ devel mailing list -- devel@xxxxxxxxxxxxxxxxxxxxxxx To unsubscribe send an email to devel-leave@xxxxxxxxxxxxxxxxxxxxxxx Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@xxxxxxxxxxxxxxxxxxxxxxx
