> -----Original Message----- > From: ceph-users [mailto:ceph-users-boun...@lists.ceph.com] On Behalf Of > Sage Weil > Sent: 29 April 2015 17:46 > To: Nick Fisk > Cc: ceph-users@lists.ceph.com > Subject: Re: [ceph-users] Cache Pool PG Split > > On Wed, 29 Apr 2015, Nick Fisk wrote: > > Hi All, > > > > When trying to increase the number of PG's of a cache pool I get the > > warning message about running a scrub afterwards and being careful > > about not overfilling the pool. I've also looked at this issue to > > better understand the underlying cause: > > http://tracker.ceph.com/issues/8043 > > > > Am I best to lower the target_max_bytes and minimising IO prior to > > doing the PG split to avoid filling the pool? Is there anything else I > > should be aware of? > > It depends on how quickly to expect it to fill up. If your disks are close > to full, > then yeah, give yourself some extra space.
Thanks for your reply Sage, I have started expanding in small increments and am not seeing any adverse effects. > > The OSDs will automatically trigger an immediate scrub of the split PGs, so > the window shouldn't be too long. Try doing a small split (increase pg_num > by 1) and see how long it takes the PG to split and scrub. > > sage > > _______________________________________________ > ceph-users mailing list > ceph-users@lists.ceph.com > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com Nick Fisk Technical Support Engineer System Professional Ltd tel: 01825 830000 mob: 07711377522 fax: 01825 830001 mail: nick.f...@sys-pro.co.uk web: www.sys-pro.co.uk<http://www.sys-pro.co.uk> IT SUPPORT SERVICES | VIRTUALISATION | STORAGE | BACKUP AND DR | IT CONSULTING Registered Office: Wilderness Barns, Wilderness Lane, Hadlow Down, East Sussex, TN22 4HU Registered in England and Wales. Company Number: 04754200 Confidentiality: This e-mail and its attachments are intended for the above named only and may be confidential. If they have come to you in error you must take no action based on them, nor must you copy or show them to anyone; please reply to this e-mail and highlight the error. Security Warning: Please note that this e-mail has been created in the knowledge that Internet e-mail is not a 100% secure communications medium. We advise that you understand and observe this lack of security when e-mailing us. Viruses: Although we have taken steps to ensure that this e-mail and attachments are free from any virus, we advise that in keeping with good computing practice the recipient should ensure they are actually virus free. Any views expressed in this e-mail message are those of the individual and not necessarily those of the company or any of its subsidiaries. _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
