Possibly MySQL is doing sync writes, where as your FIO could be doing buffered writes.
Try enabling the sync option on fio and compare results. > -----Original Message----- > From: ceph-users [mailto:ceph-users-boun...@lists.ceph.com] On Behalf Of > Matteo Dacrema > Sent: Wednesday, 8 March 2017 7:52 AM > To: ceph-users > Subject: [ceph-users] MySQL and ceph volumes > > Hi All, > > I have a galera cluster running on openstack with data on ceph volumes > capped at 1500 iops for read and write ( 3000 total ). > I can’t understand why with fio I can reach 1500 iops without IOwait and > MySQL can reach only 150 iops both read or writes showing 30% of IOwait. > > I tried with fio 64k block size and various io depth ( 1.2.4.8.16….128) and I > can’t reproduce the problem. > > Anyone can tell me where I’m wrong? > > Thank you > Regards > Matteo > > _______________________________________________ > ceph-users mailing list > ceph-users@lists.ceph.com > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com Confidentiality: This email and any attachments are confidential and may be subject to copyright, legal or some other professional privilege. They are intended solely for the attention and use of the named addressee(s). They may only be copied, distributed or disclosed with the consent of the copyright owner. If you have received this email by mistake or by breach of the confidentiality clause, please notify the sender immediately by return email and delete or destroy all copies of the email. Any confidentiality, privilege or copyright is not waived or lost because this email has been sent to you by mistake. _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
