On Wed, Dec 11, 2013 at 6:13 PM, Sherry Shahbazi <shoosah@xxxxxxxxx> wrote: > > Hi all, > > I was wondering if u could answer my question regarding cache pool: > If I have got two servers with 1 SSD in front of each of them, what CRUSH > map would be like? > > For example: > If I have defined the following CRUSH map: > http://ceph.com/docs/master/rados/operations/crush-map/#placing-different-pools-on-different-osds > and then I do the following: > http://ceph.com/docs/master/dev/cache-pool/#interface You're poking around in the dev docs there, which should be your first hint that it's not ready for user consumption yet. :) > So do I need to change the CRUSH map in terms of the cache pool. The cache pools are a feature that are in dev releases but won't be usable for much of anything until we finish some of the Firefly work that we're doing right now. When they *are* ready for users, it won't require anything specific of your CRUSH map. The cache pools will simply let you specify that pool foo is cached by pool bar (and presumably the user has arranged things so that bar is faster than foo). So probably in your case, you'd have a pool with your regular hard drives, and a separate pool on the SSDs, and you'd specify the SSD pool as a cache pool. The specific way you'd have to structure your CRUSH map to have those pools mapped onto the hard drives and SSDs correctly varies depending on how they're actually located, but in general what you'd do is specify a CRUSH rule for your normal drives, which only accesses OSDs created on them, and a separate CRUSH rule for your SSDs. -Greg Software Engineer #42 @ http://inktank.com | http://ceph.com _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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