On 08/13/2013 09:47 AM, Dmitry Postrigan wrote: >> Why would you want to make this switch? > > I do not think RAID-10 on 6 3TB disks is going to be reliable at all. I have simulated several failures, and > it looks like a rebuild will take a lot of time. Funnily, during one of these experiments, another drive > failed, and I had lost the entire array. Good luck recovering from that... good point. > I feel that Ceph is better than mdraid because: > 1) When ceph cluster is far from being full, 'rebuilding' will be much faster vs mdraid true > 2) You can easily change the number of replicas true > 3) When multiple disks have bad sectors, I suspect ceph will be much easier to recover data from than from > mdraid which will simply never finish rebuilding. maybe not true. also if you have one disk that is starting to be slow (because of upcoming failure), ceph will slow down drastically, and you need to find the failing disk. > 4) If we need to migrate data over to a different server with no downtime, we just add more OSDs, wait, and > then remove the old ones :-) true. but maybe not as easy and painless as you would expect it to be. also bear in mind that ceph needs a monitor up and running all time. > This is my initial observation though, so please correct me if I am wrong. ceph is easier to maintain than most distributed systems I know, but still harder than a local RAID. Keep that in mind. > Dmitry Wolfgang > _______________________________________________ > ceph-users mailing list > ceph-users@xxxxxxxxxxxxxx > http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com > -- DI (FH) Wolfgang Hennerbichler Software Development Unit Advanced Computing Technologies RISC Software GmbH A company of the Johannes Kepler University Linz IT-Center Softwarepark 35 4232 Hagenberg Austria Phone: +43 7236 3343 245 Fax: +43 7236 3343 250 wolfgang.hennerbichler@xxxxxxxxxxxxxxxx http://www.risc-software.at _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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