Proper stride and stripe-width for RAID 50
David Shaw <[email protected]> Tue, 5 Jun 2012 12:12:37 -0400
| Newsgroups | gmane.comp.file-systems.ext3.user |
|---|---|
| Message-ID | <[email protected]> |
Hello, I've been looking around, but can't seem to find an authoritative statement on setting stride and stripe-width for RAID 50 (i.e. a RAID 0 over multiple RAID 5s) Based on my understanding of what stride and stripe-width set, it seems to me that it should be calculated the same as it would be if there were no multiple-level RAIDing involved. For example, given a RAID 50 made up of two 3+1 RAID 5s striped together (so 8 disks total) with a 512k chunk size and 4k block size, the stride should be 128 (512 / 4) and the stripe-width should be 768 (stride * 6 data disks). These settings should work equally well whether the two RAID 5s are striped together or just appended one after the other via LVM. Is my reasoning correct? David