Hi all, I've got servers (Dell R730xd) with a number of drives in connected to a Dell H730 RAID controller. I'm trying to make a decision about whether I should put the drives in "Non-RAID" mode, or if I should make individual RAID 0 arrays for each drive. Going for the RAID 0 approach would mean that the cache on the controller will be used for the drives giving some increased performance. But it comes at the expense of less direct access to the disks for the operating system and Ceph, and I have had one oddity[1] with a drive that went away when switched from RAID 0 to Non-RAID. There are currently no SSDs being used as journals in the machines, so the increased performance is beneficial, but data integrity is obviously paramount. I've seen recommendations both ways on this list, so I'm hoping for feedback from people who've made the same decision, possibly with evidence (postive or negative) about either approach. Thanks! Tim. [1] The OS was getting I/O errors when reading certain files which gave scrub errors. No problems were shown in the RAID controller, and a check of the disk didn't reveal any issues. Switching to Non-RAID mode and recreating the OSD fixed the problem and there haven't been any issues since. -- Tim Bishop http://www.bishnet.net/tim/ PGP Key: 0x6C226B37FDF38D55 _______________________________________________ ceph-users mailing list ceph-users@xxxxxxxxxxxxxx http://lists.ceph.com/listinfo.cgi/ceph-users-ceph.com
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