On Sat Sep 28, 2013 at 10:49:49AM -0400, Matt Callaghan wrote: > Hello mdadm Linux-RAID experts; > > My Goal: Expand (grow) my array from 6xHDD (RAID6) to 8xHDD (RAID6) > > This is my root cause problem: when I went to try to add the new drive > (already formatted for Linux RAID partition): > > fermulator@fermmy-server:~$ sudo mdadm --add /dev/md2000 /dev/sdq1 > mdadm: /dev/sdq1 not large enough to join array > > As I have researched and learned, I need to: > A) shrink the filesystem (ext4) -- done (shrunk by a generous 1.6GB) > B) shrink the array size -- incomplete (unable to proceed, the --grow > command doesn't do anything) > > I've been following this guide: > http://webapp5.rrz.uni-hamburg.de/SuSe-Dokumentation/manual/sles-manuals_en/manual/raidresize.html#resizedecrraid > > > This pastebin shows my array details, the 'existing' drives (fdisk) and > 'new' drives (fdisk) - http://pastebin.com/U04VJpE4 > > Any ideas? > Firstly, your new drives are exactly the same size as the old ones: Disk /dev/sdk: 2000.4 GB, 2000398934016 bytes Disk /dev/sdq: 2000.4 GB, 2000398934016 bytes Your partition sizes are different though, probably because newer versions on fdisk default to a higher start point. You can replicate the partitions from the old disks onto the new ones using sfdisk: sfdisk -d /dev/sdk | sfdisk /dev/sdq You can do the same thing manually using fdisk - just make sure you set the units to sectors (fdisk -u=sectors) as the cylinder information differs between the disks (and is obsolete and meaningless). If you do want to stick with the partitions you have and continue with shrinking the array, the value passed with the "-z" parameter is the device size, not the array size. You're passing a value larger than the disk size, so it's being ignored. It also needs to be a multiple of the chunk size (64k in your case). So you need to take your 7812441960, divide by the number of active disks (4) and round up to the nearest 64k. This gives you a new device size of 1953110528. Cheers, Robin -- ___ ( ' } | Robin Hill <robin@xxxxxxxxxxxxxxx> | / / ) | Little Jim says .... | // !! | "He fallen in de water !!" |
Attachment:
signature.asc
Description: Digital signature
