I agree, please check for min_size to cover min 1 max 2 configs as we have done in our software for our users since years. It is important and it can prevent lot's of issues. -- Martin Verges Managing director Mobile: +49 174 9335695 E-Mail: martin.verges@xxxxxxxx Chat: https://t.me/MartinVerges croit GmbH, Freseniusstr. 31h, 81247 Munich CEO: Martin Verges - VAT-ID: DE310638492 Com. register: Amtsgericht Munich HRB 231263 Web: https://croit.io YouTube: https://goo.gl/PGE1Bx Am Mo., 29. Juni 2020 um 15:06 Uhr schrieb Wout van Heeswijk <wout@xxxxxxxx >: > Hi All, > > I really like the idea of warning users against using unsafe practices. > > Wouldn't it make sense to warn against using min_size=1 instead of size=1. > > I've seen data loss happen with size=2 min_size=1 when multiple failures > occur and write have been done between the failures. Effectively the new > warning below says "It is not considered safe to run with no > redundancy". Which is true, but when failure occurs or maintenance is > executed, with size=2 and min_size=1, as soon as data is written, there > might not be data redundancy for that newly written data. A failure of > an OSD at that moment would result in data loss. > > Since you cannot run size=1 with min_size > 1, this use-case would also > be covered. > > I understand this has implications for size=2 when executing > maintenance, but I think most people are not aware of the risks they are > taking with min_size=1. Those that are aware can suppress the warning. > > * Ceph will issue a health warning if a RADOS pool's `size` is set to 1 > or in other words the pool is configured with no redundancy. This can > be fixed by setting the pool size to the minimum recommended value > with:: > ceph osd pool set <pool-name> size <num-replicas> > The warning can be silenced with:: > ceph config set global mon_warn_on_pool_no_redundancy false > > -- > kind regards, > > Wout > 42on > _______________________________________________ > ceph-users mailing list -- ceph-users@xxxxxxx > To unsubscribe send an email to ceph-users-leave@xxxxxxx > _______________________________________________ ceph-users mailing list -- ceph-users@xxxxxxx To unsubscribe send an email to ceph-users-leave@xxxxxxx
 |