On Thu Dec 11, 2014 at 07:31:31PM +0100, cvb@xxxxxxxxxxx wrote: > Apologies for raising this topic again, but I can't seem to find > anything googling, and man mdadm doesn't also give me a clue. Which > kernel version is needed to grow a near-2 RAID 10 array? > Full reshape support (changing number of devices, layout or chunk size) was introduced in 3.5 (http://kernelnewbies.org/Linux_3.5). > I'm currently running kernel 3.13.0 with mdadm 3.2.5. But I could also > use a live CD with a newer kernel, if needed. > It also requires mdadm 3.3 or above. > I have replaced the 4 disks here with larger ones (2TB drives -> 4 TB > drives), and this is what the array currently looks like: > > # mdadm --detail /dev/md0 > /dev/md0: > Version : 1.2 > Creation Time : Sat Aug 20 08:15:07 2011 > Raid Level : raid10 > Array Size : 3906764800 (3725.78 GiB 4000.53 GB) > Used Dev Size : 1953382400 (1862.89 GiB 2000.26 GB) > Raid Devices : 4 > Total Devices : 4 > Persistence : Superblock is persistent > > Update Time : Thu Dec 11 08:31:15 2014 > State : clean > Active Devices : 4 > Working Devices : 4 > Failed Devices : 0 > Spare Devices : 0 > > Layout : near=2 > Chunk Size : 512K > > Name : alpha:0 (local to host alpha) > UUID : 8199e640:58fc3a04:99b52fe6:80a1574d > Events : 918971 > > Number Major Minor RaidDevice State > 6 8 1 0 active sync /dev/sda1 > 5 8 33 1 active sync /dev/sdc1 > 7 8 17 2 active sync /dev/sdb1 > 4 8 49 3 active sync /dev/sdd1 > I can't find anything explicitly covering growing a RAID 10 by just increasing the device sizes. I would have thought that would be an easier task than doing so by adding disks, so should be supported in an earlier version. mdadm 3.2.1 mentions supporting converting between RAID-10 and RAID-1, which can definitely be grown. Have you tried doing a grow with the versions you have? Cheers, Robin -- ___ ( ' } | Robin Hill <robin@xxxxxxxxxxxxxxx> | / / ) | Little Jim says .... | // !! | "He fallen in de water !!" |
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