Topic: [SOLVED] 7.5.1: Problem adding larger drive

[Michail Pappas]

Hello all,

this is a 7.5.1 system that originally had a single 240Gb hard disk. Two 500Gb hard disks were bought for this purpose. This is what I did.

1) I connected only one of these two disks and followed the instructions in
http://wiki.contribs.org/Raid#Adding_another_Hard_Drive_Later

2) After the array was in sync, I shutted down the system, removed the 240Gb (old) disk and added the 2nd (new) 500Gb disk.

3) Again I followed the instructions in http://wiki.contribs.org/Raid#Adding_another_Hard_Drive_Later

4) After the disks went in sync, I tried to follow the instructions in http://wiki.contribs.org/Raid#Upgrading_the_Hard_Drive_Size
The "mdadm --grow /dev/md2 --size=max" command runs without reporting anything. Running the pvresize commands reports that "1 physical volume(s) resized / 0 physical volume(s) not resized". However, the lvresize command says that "New size (7387 extents) matches existing size (7387 extents)". Additionally looking at the disks nothing seems to have changed regarding their sizes.

Perhaps the issue is that the partitions created on the first 500Gb disk (sdb here) installed were the same in size with the original 250Gb:

Code: [Select]

# fdisk -l

Disk /dev/sda: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          13      104384+  fd  Linux raid autodetect
Partition 1 does not end on cylinder boundary.
/dev/sda2              13       60801   488279647   fd  Linux raid autodetect

Disk /dev/sdb: 250.0 GB, 250059350016 bytes
255 heads, 63 sectors/track, 30401 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1   *           1          13      104391   fd  Linux raid autodetect
/dev/sdb2              14       30401   244091610   fd  Linux raid autodetect

Disk /dev/md1: 106 MB, 106823680 bytes
2 heads, 4 sectors/track, 26080 cylinders
Units = cylinders of 8 * 512 = 4096 bytes

Disk /dev/md1 doesn't contain a valid partition table

Disk /dev/md2: 249.9 GB, 249949716480 bytes
2 heads, 4 sectors/track, 61022880 cylinders
Units = cylinders of 8 * 512 = 4096 bytes

Disk /dev/md2 doesn't contain a valid partition table

Disk /dev/dm-0: 247.8 GB, 247866589184 bytes
2 heads, 4 sectors/track, 60514304 cylinders
Units = cylinders of 8 * 512 = 4096 bytes

Disk /dev/dm-0 doesn't contain a valid partition table

Disk /dev/dm-1: 2080 MB, 2080374784 bytes
2 heads, 4 sectors/track, 507904 cylinders
Units = cylinders of 8 * 512 = 4096 bytes

Disk /dev/dm-1 doesn't contain a valid partition table

If this is the case, how can I correct it? FYI, output of cat /proc/mdstat / lvdisplay/pvdisplay/vgdisplay follows:

Code: [Select]

# cat /proc/mdstat
Personalities : [raid1]
md2 : active raid1 sdb2[0] sda2[1]
      244091520 blocks [2/2] [UU]

md1 : active raid1 sdb1[0] sda1[1]
      104320 blocks [2/2] [UU]

unused devices: <none>

# vgdisplay
  --- Volume group ---
  VG Name               main
  System ID
  Format                lvm2
  Metadata Areas        1
  Metadata Sequence No  5
  VG Access             read/write
  VG Status             resizable
  MAX LV                0
  Cur LV                2
  Open LV               2
  Max PV                0
  Cur PV                1
  Act PV                1
  VG Size               232.78 GB
  PE Size               32.00 MB
  Total PE              7449
  Alloc PE / Size       7449 / 232.78 GB
  Free  PE / Size       0 / 0

# pvdisplay
  --- Physical volume ---
  PV Name               /dev/md2
  VG Name               main
  PV Size               232.78 GB / not usable 2.44 MB
  Allocatable           yes (but full)
  PE Size (KByte)       32768
  Total PE              7449
  Free PE               0
  Allocated PE          7449

# lvdisplay
  --- Logical volume ---
  LV Name                /dev/main/root
  VG Name                main
  LV UUID                xxxxxxxxxxxxxxxxxxx
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                230.84 GB
  Current LE             7387
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:0

  --- Logical volume ---
  LV Name                /dev/main/swap
  VG Name                main
  LV UUID                xxxxxxxxxxxxxxxx
  LV Write Access        read/write
  LV Status              available
  # open                 1
  LV Size                1.94 GB
  Current LE             62
  Segments               1
  Allocation             inherit
  Read ahead sectors     auto
  - currently set to     256
  Block device           253:1

# mount
/dev/mapper/main-root on / type ext3 (rw,usrquota,grpquota)
none on /proc type proc (rw)
none on /sys type sysfs (rw)
none on /dev/pts type devpts (rw,gid=5,mode=620)
usbfs on /proc/bus/usb type usbfs (rw)
/dev/md1 on /boot type ext3 (rw)
none on /dev/shm type tmpfs (rw)
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)

[Michail Pappas]

Seems likely that in step (4) of the OP and immediately after the second new disk gets sync'ed, the first large disk added has to be removed from the md arrays, have its partitions erased and then be re-added to md, before the relevant commands in http://wiki.contribs.org/Raid#Upgrading_the_Hard_Drive_Size are ran. Will confirm this, as soon as the procedure over here finishes.

[Michail Pappas]

Well, that didn't work. What worked was modifying steps 2- into the following:

2) After the array was in sync, I shutted down the system, removed the 240Gb (old) disk but did not add the 2nd new hard disk immediately. Instead I followed the instructions in http://wiki.contribs.org/Raid#Upgrading_the_Hard_Drive_Size, running the 4 commands listed. Now the partitions of the (single) disk reflected the real size of the disk!

3) I shutted down and added the 2nd new disk. I followed the instructions in http://wiki.contribs.org/Raid#Adding_another_Hard_Drive_Later

4) That's all

As you can see, the main difference is correcting for the incorrect partition size created in the smaller disk, by doing the lvm/md extension commands while there is only a single new/large disk in the array.

Not sure if this correct here or not, hope it is

[Michail Pappas]

Ok, this is turning into a monologue

This did work. That is, removing the disk from the array. However, for some reason the arrays md1/2 are listed as degraded, whereas there seems to be a ghost of the disk I removed:

Code: [Select]

# mdadm --detail /dev/md2
/dev/md2:
        Version : 00.90.01
  Creation Time : Wed May  4 15:20:53 2011
     Raid Level : raid1
     Array Size : 488279552 (465.66 GiB 500.00 GB)
    Device Size : 488279552 (465.66 GiB 500.00 GB)
   Raid Devices : 2
  Total Devices : 1
Preferred Minor : 2
    Persistence : Superblock is persistent

    Update Time : Wed Jul 13 14:20:40 2011
          State : clean, degraded
 Active Devices : 1
Working Devices : 1
 Failed Devices : 0
  Spare Devices : 0

           UUID : 50cb3364:08bd93ef:7a106c13:4908045e
         Events : 0.2359579

    Number   Major   Minor   RaidDevice State
       0       0        0        -      removed
       1       8        2        1      active sync   /dev/sda2
As a result, I can not add the second disk to the array. What should I do?

[Michail Pappas]

Problem solved, last post above was an error of mine.