> -----Original Message----- > From: ceph-users [mailto:ceph-users-boun...@lists.ceph.com] On Behalf Of > Nick Fisk > Sent: 13 August 2015 18:04 > To: ceph-users@lists.ceph.com > Subject: [ceph-users] How to improve single thread sequential reads? > > Hi, > > I'm trying to use a RBD to act as a staging area for some data before pushing > it down to some LTO6 tapes. As I cannot use striping with the kernel client I > tend to be maxing out at around 80MB/s reads testing with DD. Has anyone > got any clever suggestions of giving this a bit of a boost, I think I need to get it > up to around 200MB/s to make sure there is always a steady flow of data to > the tape drive.
I've just tried the testing kernel with the blk-mq fixes in it for full size IO's, this combined with bumping readahead up to 4MB, is now getting me on average 150MB/s to 200MB/s so this might suffice. On a personal interest, I would still like to know if anyone has ideas on how to really push much higher bandwidth through a RBD. > > Rbd-fuse seems to top out at 12MB/s, so there goes that option. > > I'm thinking mapping multiple RBD's and then combining them into a mdadm > RAID0 stripe might work, but seems a bit messy. > > Any suggestions? > > Thanks, > Nick > _______________________________________________ ceph-users mailing list ceph-users@lists.ceph.com http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
