I'm interested in such a configuration, can you share some perfomance test/numbers?
Thanks in advance, Best regards, *German* 2015-07-01 21:16 GMT-03:00 Shane Gibson <shane_gib...@symantec.com>: > > It also depends a lot on the size of your cluster ... I have a test > cluster I'm standing up right now with 60 nodes - a total of 600 OSDs each > at 4 TB ... If I lose 4 TB - that's a very small fraction of the data. My > replicas are going to be spread out across a lot of spindles, and > replicating that missing 4 TB isn't much of an issue, across 3 racks each > with 80 gbit/sec ToR uplinks to Spine. Each node has 20 gbit/sec to ToR in > a bond. > > On the other hand ... if you only have 4 .. or 8 ... or 10 servers ... and > a smaller number of OSDs - you have fewer spindles replicating that loss, > and it might be more of an issue. > > It just depends on the size/scale of your environment. > > We're going to 8 TB drives - and that will ultimately be spread over a 100 > or more physical servers w/ 10 OSD disks per server. This will be across > 7 to 10 racks (same network topology) ... so an 8 TB drive loss isn't too > big of an issue. Now that assumes that replication actually works well in > that size cluster. We're still cessing out this part of the PoC > engagement. > > ~~shane > > > > > On 7/1/15, 5:05 PM, "ceph-users on behalf of German Anders" < > ceph-users-boun...@lists.ceph.com on behalf of gand...@despegar.com> > wrote: > > ask the other guys on the list, but for me to lose 4TB of data is to much, > the cluster will still running fine, but in some point you need to recover > that disk, and also if you lose one server with all the 4TB disk in that > case yeah it will hurt the cluster, also take into account that with that > kind of disk you will get no more than 100-110 iops per disk > > *German Anders* > Storage System Engineer Leader > *Despegar* | IT Team > *office* +54 11 4894 3500 x3408 > *mobile* +54 911 3493 7262 > *mail* gand...@despegar.com > > 2015-07-01 20:54 GMT-03:00 Nate Curry <cu...@mosaicatm.com>: > >> 4TB is too much to lose? Why would it matter if you lost one 4TB with >> the redundancy? Won't it auto recover from the disk failure? >> >> Nate Curry >> On Jul 1, 2015 6:12 PM, "German Anders" <gand...@despegar.com> wrote: >> >>> I would probably go with less size osd disks, 4TB is to much to loss in >>> case of a broken disk, so maybe more osd daemons with less size, maybe 1TB >>> or 2TB size. 4:1 relationship is good enough, also i think that 200G disk >>> for the journals would be ok, so you can save some money there, the osd's >>> of course configured them as a JBOD, don't use any RAID under it, and use >>> two different networks for public and cluster net. >>> >>> *German* >>> >>> 2015-07-01 18:49 GMT-03:00 Nate Curry <cu...@mosaicatm.com>: >>> >>>> I would like to get some clarification on the size of the journal disks >>>> that I should get for my new Ceph cluster I am planning. I read about the >>>> journal settings on >>>> http://ceph.com/docs/master/rados/configuration/osd-config-ref/#journal-settings >>>> but that didn't really clarify it for me that or I just didn't get it. I >>>> found in the Learning Ceph Packt book it states that you should have one >>>> disk for journalling for every 4 OSDs. Using that as a reference I was >>>> planning on getting multiple systems with 8 x 6TB inline SAS drives for >>>> OSDs with two SSDs for journalling per host as well as 2 hot spares for the >>>> 6TB drives and 2 drives for the OS. I was thinking of 400GB SSD drives but >>>> am wondering if that is too much. Any informed opinions would be >>>> appreciated. >>>> >>>> Thanks, >>>> >>>> *Nate Curry* >>>> >>>> >>>> _______________________________________________ >>>> ceph-users mailing list >>>> ceph-users@lists.ceph.com >>>> http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com >>>> >>>> >>> >
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