OSD numbers are 2^32 On 30/10/2013 16:37, Glen Aidukas wrote:> I wanted to know, does the OSD numbering half to be sequential and what is the highest usable number (2^16 or 2^32)? > > The reason is, I would like to use a numbering convention that reflects the cluster number (assuming I will have more than one down the road; test, dev, prod), the host and disk used by a given OSD. Although it was possible in the past to assign arbitrary OSD ids ( numbers ), it is no longer possible. > > So, for example: osd.CHHHDD where: > C Cluster number 1-9 > HHH Host number IE: ceph001, ceph002, ... > DD Disk number on a given host Ex: 00 = /dev/sda or something like this. > > If the highest number usable is 65534 or near that (2^16) then maybe I could use format CHHDD or CHHHD where I could have clusters 1-5. > > The up side to this is I quickly know where osd.200503 is. It's on cluster 2 host ceph005 and the third disk. Also, if I add a new disk on a middle host, it doesn’t scatter the numbering to where I don't easily know were an OSD is. I know I can always look this up but having it as part of the OSD number makes life easier. :) > > Also, it might seem silly to have the first digit as a cluster number but I think we probable can't pad the number with zeros so using an initial digit of 1-9 cleans this up so I might as well use it to identify the cluster. > > This numbering system is not important for the monitors or metadata but could help with the OSDs. If you use "ceph osd tree" you will get a display of the hierarchical organization of your infrastructure. Is is not enough to locate the OSDs ? ceph osd root@bm0012:~# ceph osd tree # id weight type name up/down reweight -1 9 root default -2 3.59 host bm0012 0 1.82 osd.0 down 0 3 1.77 osd.3 down 0 -3 3.59 host bm0014 1 1.82 osd.1 up 1 4 1.77 osd.4 up 1 -4 1.82 host bm0015 2 1.82 osd.2 up 1 Unless you have a specific use case in mind, OSD ids can safely be ignored. I recently discovered why and "Fully automated disks life cycle in a Ceph cluster" posted at http://dachary.org/?p=2428 explains how I understand it. Cheers > > -Glen > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > -- Loïc Dachary, Artisan Logiciel Libre
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