You need to make sure SSD O_DIRECT|O_DSYNC performance is good. Not all the SSDs are good at it..Refer the prior discussions in the community for that. << Presumably as long as the SSD read speed exceeds that of the spinners, that is sufficient. You probably meant write speed of SSDs ? Journal will not be read in the IO path , it will be read only during journal replay at the time of OSD restart.. Thanks & Regards Somnath -----Original Message----- From: ceph-users [mailto:ceph-users-bounces@xxxxxxxxxxxxxx] On Behalf Of Lindsay Mathieson Sent: Friday, February 26, 2016 4:16 PM To: ceph-users@xxxxxxxxxxxxxx Subject: SSD Journal Performance Priorties Ignoring the durability and network issues for now :) Are there any aspects of a journals performance that matter most for over all ceph performance? i.e my inital thought is if I want to improve ceph write performance journal seq write speed is what matters. Does random write speed factor at all? Presumably as long as the SSD read speed exceeds that of the spinners, that is sufficient. -- Lindsay Mathieson _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com PLEASE NOTE: The information contained in this electronic mail message is intended only for the use of the designated recipient(s) named above. If the reader of this message is not the intended recipient, you are hereby notified that you have received this message in error and that any review, dissemination, distribution, or copying of this message is strictly prohibited. If you have received this communication in error, please notify the sender by telephone or e-mail (as shown above) immediately and destroy any and all copies of this message in your possession (whether hard copies or electronically stored copies). _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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