On Fri, Apr 22, 2016 at 4:09 PM, Sage Weil <sweil@xxxxxxxxxx> wrote: > On Fri, 22 Apr 2016, Dan van der Ster wrote: >> Hi Mark, >> >> On Fri, Apr 15, 2016 at 2:06 PM, Mark Nelson <mnelson@xxxxxxxxxx> wrote: >> > Hi all, >> > >> > A couple of folks have asked me how to setup bluestore clusters for >> > performance testing. I personally am using cbt for this, but you should be >> > able to use ceph-disk with some other cluster creation method as well. >> > >> > For CBT, you really don't need to do much. In the old newstore days, a >> > "block" symlink needed to be created in the osd data dir to link to the new >> > block device. CBT did this when the "newstore_block: True" option was set >> > in the cluster section of the cbt yaml file. This isn't really needed >> > anymore, as you can now specify the block, db, and wal devices directly in >> > your ceph.conf file. If your partitions are setup properly you can create >> > bluestore clusters without having to do anything beyond changing the >> > ceph.conf file (with cbt at least). >> > >> > Here's a very basic example: >> > >> > [global] >> > enable experimental unrecoverable data corrupting features = >> > bluestore rocksdb >> > osd objectstore = bluestore >> > >> > [osd.0] >> > host = incerta01.front.sepia.ceph.com >> > osd data = /tmp/cbt/mnt/osd-device-0-data >> > bluestore block path = /dev/disk/by-partlabel/osd-device-0-block >> > bluestore block db path = /dev/disk/by-partlabel/osd-device-0-db >> > bluestore block wal path = /dev/disk/by-partlabel/osd-device-0-wal >> >> The db and wal paths are optional perf boosting things, right? > > Yeah. > >> If I do ceph-disk prepare --bluestore /dev/sdae, I get: >> >> /dev/sdae : >> /dev/sdae2 ceph block, for /dev/sdae1 >> /dev/sdae1 ceph data, active, cluster ceph, osd.413, block /dev/sdae2 > > Looks right! ceph-disk isn't smart enough to set up the wal or db devices > yet. > > The wal device should default to something like 128 MB. > > The db device would be whatever portion of an SSD you want to allocate to > storing the bluestore metadata. My guess is that we'll get further than > we did with FileStore, so the old 1:4 or 1:5 rule of thumb might be more > like 1:10, but who knows--this'll require some testing. Cool, I'll start testing wal/db on SSDs with some new machines ~next week. Just to clarify, if we give no wal, there is no wal, right? But if we don't give a dedicated db device, where does the db go? Also, bluestore being experimental in jewel -- I guess that means you don't promise to support the current on disk format in kraken and beyond? Thanks! Dan > > sage > -- To unsubscribe from this list: send the line "unsubscribe ceph-devel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
