Linux LVM Query

[Duffster]

Hi,

I have extended the logical drive on my SMART ARRAY on a BL460 C class blade from 72G to 300G (disk upgrade RAID0+1).
It went fine and the new larger disks have now sync'ed up.

I now need to create  additional disk space on my linux OS (RH) via LVM but I am unable to see the additional space on the OS. The 'fdisk' does not show any additional partitions or space? Can anyone please advise how this additional space can get presented to the OS?

R,

D.

[Matti_Kurkela]

Which generation is your blade? The original BL460c, or one of the upgraded models (G5, G6 or G7)?

What's the name and version of your Linux distribution?

Have you used the ACU (either the web GUI version or the command-line hpacucli) to extend the logical drive, or have you only swapped the disks for larger ones at this point? If you haven't used ACU yet, that's the first step. After that, the partitioning tools should indicate that the logical disk is now larger than the sum of existing partitions: if it doesn't, you need to do something (on non-ancient Linux distributions, run "partprobe" if it's available; on very old distributions you might have to reboot) to make the OS recognize the new size.

Since we're talking about a blade, this logical drive is probably the system disk, right? If so, then it must have a traditional PC partition table, and you must then use one of the fdisk-like tools (parted/cfdisk/sfdisk/fdisk, in a rough order of decreasing preference to me) to either add a new partition or to extend partition that is currently the last one on the disk.

Are you using LVM, or is your current layout based on traditional partitions only? If you're already using LVM, you can just create a new partition using the added space, set its type to "Linux LVM", pvcreate it and then add it to your existing volume group with vgextend. Then you can use the lvextend command to extend your existing logical volumes, or lvcreate to create new ones. If you extend a logical volume, the last step will be to use the appropriate filesystem extension command (e.g. resize2fs for ext2/ext3/ext4 filesystems, resize_reiserfs for ReiserFS, etc.) to make the added space available to the filesystem = visible with commands like "df".

[Duffster]

Hi Matti,

Thanks for the feedback!

I am using BL460 G6, RHEL 5 (32-bit).

I have used the ACU and successfully extended the current logical drive from 73G to 300G.

I can see from fdisk that the logical partition has increased accordingly.

The logical drive is the system disk.

I have used fdisk and created a new partition from the extended LVM partition but I get the following error when I attempt to pvcreate it:

             Device Boot      Start         End      Blocks   Id  System
/dev/cciss/c0d0p5p1               1       16210    66136784   83  Linux

#[root@XXDBS2 ~]# pvcreate /dev/cciss/c0d0p5p1
  Device /dev/cciss/c0d0p5p1 not found (or ignored by filtering)

Any ideas how I can view the additional space on my logical drive??

R,
D.

[Matti_Kurkela]

/dev/cciss/c0d0p5p1 does not look like a normal SmartArray logical device name. Perhaps your fdisk output has multiple lines jumbled together for some reason? Or did you manage to create another partition table within existing partition 5?

The syntax should be /dev/cciss/c<controller>d<logicaldrive>p<partition>, where <controller>, <logicaldrive> and <partition> are numbers only.

While fdisk may be able to create a partition table within an already-existing partition, it's unlikely to work: the kernel will only read one PC-style partition table at the beginning of the disk. It won't expect a second tier of partitioning unless you use special procedures... but that would be a rather strange configuration.

You should have pointed the fdisk command to the whole-disk device, i.e. /dev/cciss/c0d0.

Run "cat /proc/partitions" or "ls /dev/cciss" to see the actual device names.