- Extend the LUN from storage device (IBM DS, IBM Storwize etc).
- Identify the SCSI device for this LUN.
# multipath -ll
mpath21 (3600a0b80003ac4d800001057506d4309) dm-1 IBM,1726-4xx FAStT
size=6.0G features='1 queue_if_no_path' hwhandler='1 rdac' wp=rw
|-+- policy='round-robin 0' prio=6 status=active
| `- 3:0:0:21 sdf 8:80 active ready running
`-+- policy='round-robin 0' prio=1 status=enabled
`- 2:0:0:21 sdc 8:32 active ghost running - Rescan the SCSI device
# echo 1 > /sys/block/sdf/device/rescan
# echo 1 > /sys/block/sdc/device/rescan - Reload multipathd service
# service multipathd reload
Reloading multipathd: [ OK ] - Check and verify multipath whether it claims the new LUN size
# multipath -ll
mpath21 (3600a0b80003ac4d800001057506d4309) dm-1 IBM,1726-4xx FAStT
size=7.0G features='1 queue_if_no_path' hwhandler='1 rdac' wp=rw
|-+- policy='round-robin 0' prio=6 status=active
| `- 3:0:0:21 sdf 8:80 active ready running
`-+- policy='round-robin 0' prio=1 status=enabled
`- 2:0:0:21 sdc 8:32 active ghost running - Unmount the partition
# umount /dev/mapper/mpath21p1 - Fdisk the device, drop and recreate the partition with desired size. I’ll also do the 64k block alignment do get the maximum performance.
Before deleting partition check start sector for partition. Because partition may start from 63 sector (not aligned) or 64 sector (aligned).# fdisk /dev/mapper/mpath21WARNING: DOS-compatible mode is deprecated. It's strongly recommended to
switch off the mode (command 'c') and change display units to
sectors (command 'u').Command (m for help): pDisk /dev/mapper/mpath21: 7516 MB, 7516192768 bytes
255 heads, 63 sectors/track, 913 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xab317070Device Boot Start End Blocks Id System
/dev/mapper/mpath21p1 1 783 6289415+ 83 Linux
Partition 1 has different physical/logical beginnings (non-Linux?):
phys=(0, 1, 1) logical=(0, 1, 2)
--------------Here we check start sector for partitionCommand (m for help): x
Expert command (m for help): p
Disk /dev/mapper/mpath21: 255 heads, 63 sectors, 913 cylindersNr AF Hd Sec Cyl Hd Sec Cyl Start Size ID
1 00 1 1 0 254 63 782 64 12578831 83
Partition 1 has different physical/logical beginnings (non-Linux?):
phys=(0, 1, 1) logical=(0, 1, 2)
2 00 0 0 0 0 0 0 0 0 00
3 00 0 0 0 0 0 0 0 0 00
4 00 0 0 0 0 0 0 0 0 00Expert command (m for help): rCommand (m for help): d
Selected partition 1Command (m for help): pDisk /dev/mapper/mpath21: 7516 MB, 7516192768 bytes
255 heads, 63 sectors/track, 913 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0xab317070Device Boot Start End Blocks Id SystemCommand (m for help): n
Command action
e extended
p primary partition (1-4)
p
Partition number (1-4): 1
First cylinder (1-913, default 1):
Using default value 1
Last cylinder, +cylinders or +size{K,M,G} (1-913, default 913):
Using default value 913Command (m for help): xExpert command (m for help): b
Partition number (1-4): 1
New beginning of data (1-14667344, default 63): 64Expert command (m for help): pDisk /dev/mapper/mpath21: 255 heads, 63 sectors, 913 cylindersNr AF Hd Sec Cyl Hd Sec Cyl Start Size ID
1 00 1 1 0 254 63 912 64 14667281 83
Partition 1 has different physical/logical beginnings (non-Linux?):
phys=(0, 1, 1) logical=(0, 1, 2)
2 00 0 0 0 0 0 0 0 0 00
3 00 0 0 0 0 0 0 0 0 00
4 00 0 0 0 0 0 0 0 0 00Expert command (m for help): rCommand (m for help): w
The partition table has been altered!Calling ioctl() to re-read partition table.WARNING: Re-reading the partition table failed with error 22: Invalid argument.
The kernel still uses the old table. The new table will be used at
the next reboot or after you run partprobe(8) or kpartx(8)
Syncing disks. - Let kernel identify the new partition table.
# partprobe
Warning: WARNING: the kernel failed to re-read the partition table on /dev/sda (Device or resource busy). As a result, it may not reflect all of your changes until after reboot.
Warning: WARNING: the kernel failed to re-read the partition table on /dev/sdd (Device or resource busy). As a result, it may not reflect all of your changes until after reboot.
device-mapper: remove ioctl on mpathfp1 failed: Device or resource busy
Warning: parted was unable to re-read the partition table on /dev/mapper/mpathf (No such file or directory). This means Linux won't know anything about the modifications you made.
device-mapper: create ioctl on mpathfp1 failed: Device or resource busy
device-mapper: remove ioctl on mpathfp1 failed: Device or resource busy
This warnings and errors is normal because other partition is still mounted. - Add the partitioning table to device mapper.
# kpartx -a /dev/mapper/mpath21 - Run filesystem check.
# e2fsck -f /dev/mapper/mpath21p1
e2fsck 1.41.12 (17-May-2010)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/mapper/mpath21p1: 12/393216 files (8.3% non-contiguous), 85614/1572353 blocks - Extend the filesystem.
# resize2fs /dev/mapper/mpath21p1
resize2fs 1.41.12 (17-May-2010)
Resizing the filesystem on /dev/mapper/mpath21p1 to 1833410 (4k) blocks.
The filesystem on /dev/mapper/mpath21p1 is now 1833410 blocks long. - Mount partition and check new size.
# mount -a
# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/mpath21p1
6.9G 240M 6.4G 4% /test
Xming X Server for Windows