On Mon, Jan 2, 2017 at 6:46 AM, Wido den Hollander <[email protected]> wrote:
> > > Op 2 januari 2017 om 15:43 schreef Matteo Dacrema <[email protected]>: > > > > > > Increasing pg_num will lead to several slow requests and cluster freeze, > but due to creating pgs operation , for what I’ve seen until now. > > During the creation period all the request are frozen , and the creation > period take a lot of time even for 128 pgs. > > > > I’ve observed that during creation period most of the OSD goes at 100% > of their performance capacity. I think that without operation running in > the cluster I’ll be able to upgrade pg_num quickly without causing down > time several times. > > > > First, slowly increase pg_num to the number you want, then increase > pgp_num in small baby steps as well. > > Wido > As Wido mentioned, low+slow is the way to go for production environments. increase in small increments. pg_num increases should be fairly transparent to client IO, but test first by increasing your pool in increasing amounts. pgp_num increase will cause client interruption in a lot of cases, so this is what you'll need to be wary of. Here's some select logic from a quick and dirty script I wrote to do the last PG increase job, maybe it will help in your endeavors: https://gist.github.com/oddomatik/7cca9b64d7b13d17e800cc35894037ac > > > Matteo > > > > > Il giorno 02 gen 2017, alle ore 15:02, [email protected] ha scritto: > > > > > > Well, as the doc said: > > >> Set or clear the pause flags in the OSD map. If set, no IO requests > will be sent to any OSD. Clearing the flags via unpause results in > resending pending requests. > > > If you do that on a production cluster, that means your cluster will no > > > longer be in production :) > > > > > > Depending on your needs, but .. > > > Maybe you want do this operation as fast as possible > > > Or maybe you want to make that operation as transparent as possible, > > > from a user point of view > > > > > > You may have a look at osd_recovery_op_priority & > > > osd_client_op_priority, they might be interesting for you > > > > > > On 02/01/2017 14:37, Matteo Dacrema wrote: > > >> Hi All, > > >> > > >> what happen if I set pause flag on a production cluster? > > >> I mean, will all the request remain pending/waiting or all the > volumes attached to the VMs will become read-only? > > >> > > >> I need to quickly upgrade placement group number from 3072 to 8192 or > better to 165336 and I think doing it without client operations will be > much faster. > > >> > > >> Thanks > > >> Regards > > >> Matteo > > >> > > >> > > >> > > >> > > >> _______________________________________________ > > >> ceph-users mailing list > > >> [email protected] > > >> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > > >> > > > > > > _______________________________________________ > > > ceph-users mailing list > > > [email protected] > > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > > > > > > -- > > > Questo messaggio e' stato analizzato con Libra ESVA ed e' risultato > non infetto. > > > Seguire il link qui sotto per segnalarlo come spam: > > > http://mx01.enter.it/cgi-bin/learn-msg.cgi?id=9F3C956B85.A333A > > > > > > > > > > _______________________________________________ > > ceph-users mailing list > > [email protected] > > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > _______________________________________________ > ceph-users mailing list > [email protected] > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > -- Brian Andrus Cloud Systems Engineer DreamHost, LLC
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