>>> On Wed, 27 Jul 2016 14:44:03 +0100, Wols Lists <antlists@xxxxxxxxxxxxxxx> said: > On 27/07/16 14:22, Peter Grandi wrote: >> Also, if the data is just 4.5TB, why not go for just a 3x >> RAID5 with the 3x 4TB drives, which a usable capacity of 8TB? >> A degree of redundancy of 1-in-3 is not bad. It would have >> less IOPS though. > The problem is that one of the three new 4TB drives is > currently part of the old - partly failed - array. So without > buying a fourth 4TB drive, that option isn't on the table. A and B are the 2TB drives, C, D and E the 4TB drives. * Copy the 4.5TB if they can be compressed to drive E (it does not neet to be partitioned). * Setup drives C and D as a degraded (3-1)x RAID5. * Create a RAID0 of the 2x 2TB drives. * Add the RAID0 as the 3rd member to the new RAID5. * Copy the 4.5TB from drive E to the new RAID5. * Wait for sync to finish. * Stop the RAID5 set. * Copy by 'dd' the RAID0 set's content to drive E. * Stop the RAID0 set and '--zero' A and B. * Start the RAID5. * Reuse A and B for something else. -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
