0

I had a Raid6 with 2TB disks, and have now replace all of them with 4TB disks. I pulled them out one at the time, after installing the new 4TB disk I added to /dev/md2

mdadm --manage /dev/md2 --add /dev/sdx

After changed all 7 of them I tried to grow the Raid

mdadm --grow /dev/md2 --size=max

But it only got me a little bit more disk, so the following resize2fs /dev/md2 gave me nearly nothing.

$ cat /proc/mdstat

Personalities : [linear] [multipath] [raid0] [raid1] [raid6] [raid5] [raid4] [raid10] 
md2 : active raid6 sdc[6] sdi[5] sdd[4] sde[0] sdf[1] sdg[2] sdh[3]
      10737417600 blocks level 6, 64k chunk, algorithm 2 [7/7] [UUUUUUU]

$ uname -a

Linux TheNewServer 3.2.0-59-generic #90-Ubuntu SMP Tue Jan 7 22:43:51 UTC 2014 x86_64 x86_64 x86_64 GNU/Linux

$ smartctl -i /dev/sdh

smartctl 5.41 2011-06-09 r3365 [x86_64-linux-3.2.0-59-generic] (local build)
Copyright (C) 2002-11 by Bruce Allen, http://smartmontools.sourceforge.net

=== START OF INFORMATION SECTION ===
Device Model:     WDC WD40EFRX-68WT0N0
Serial Number:    WD-WCC4E0836493
LU WWN Device Id: 5 0014ee 2b4608df4
Firmware Version: 80.00A80
User Capacity:    4,000,787,030,016 bytes [4.00 TB]
Sector Sizes:     512 bytes logical, 4096 bytes physical
Device is:        Not in smartctl database [for details use: -P showall]
ATA Version is:   9
ATA Standard is:  Exact ATA specification draft version not indicated
Local Time is:    Tue Mar 25 17:18:39 2014 CET
SMART support is: Available - device has SMART capability.
SMART support is: Enabled

$ df -h

/dev/md2        9.9T  8.5T  867G  91% /usr/local1
$ sudo mdadm -D /dev/md2
/dev/md2:
        Version : 0.90
  Creation Time : Fri Jul  9 00:24:49 2010
     Raid Level : raid6
     Array Size : 10737417600 (10240.00 GiB 10995.12 GB)
  Used Dev Size : 2147483520 (2048.00 GiB 2199.02 GB)
   Raid Devices : 7
  Total Devices : 7
Preferred Minor : 2
    Persistence : Superblock is persistent

  Intent Bitmap : Internal

    Update Time : Wed Mar 26 12:10:05 2014
          State : active 
 Active Devices : 7
Working Devices : 7
 Failed Devices : 0
  Spare Devices : 0

         Layout : left-symmetric
     Chunk Size : 64K

           UUID : f0114df5:20f9dafe:ee14e2d4:d0fe943c
         Events : 0.10947206

    Number   Major   Minor   RaidDevice State
       0       8       64        0      active sync   /dev/sde
       1       8       80        1      active sync   /dev/sdf
       2       8       96        2      active sync   /dev/sdg
       3       8      112        3      active sync   /dev/sdh
       4       8       48        4      active sync   /dev/sdd
       5       8      128        5      active sync   /dev/sdi
       6       8       32        6      active sync   /dev/sdc

I was expecting to see close to 20 Tb here.

6
  • Smart status on one drive isn't really relevant or useful. Try mdadm -D /dev/md2 instead.
    – psusi
    Mar 25, 2014 at 23:25
  • Added output of the mdadm -D /dev/md2. Mar 26, 2014 at 11:16
  • Double check that all of those drives are now 4 TB. If one of them is still 2TB that would cause what you are seeing.
    – psusi
    Mar 26, 2014 at 14:15
  • They are all the same, User Capacity: 4,000,787,030,016 bytes [4.00 TB] Mar 26, 2014 at 14:47
  • Check with sudo blockdev --getsize64 /dev/sd[efghdic]
    – psusi
    Mar 26, 2014 at 15:07

1 Answer 1

0

Ahh, your array is using the old 0.9 format metadata, which tops out at 2 TiB per drive. You will need to upgrade to 1.x for larger drives. You may be able to do this by stopping the array, zeroing out the superblocks, and recreating the array, taking care to use exactly the same drive order, and the chunk size, specify --metadata=1.0, and --assume-clean, then do a read only fsck to make sure you got it right and your data is intact before trying to mount it. Make sure you have an up to date backup first though ( you are making regular backups right? ).

You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .