How to extend a logical volume under linux (centos 4.4)

[Daniele Di Salvo]

Hi all,

Using ACU on our DL380 G3 with Smart Array 5i controller, we added a new physical disk to a RAID 5 array and then successfully increased the logical disk to its maximum size (69443 MB).

However, since LVM still reports a much lower capacity and no space available for extension, we are wondering what we are missing here.

Thanks

lvm> lvdisplay
--- Logical volume ---
LV Name /dev/VolGroup00/LogVol00
VG Name VolGroup00
LV UUID swJxom-32HW-Unhm-zkbr-hQsz-Wxw1-2X1acG
LV Write Access read/write
LV Status available
# open 1
LV Size 48.75 GB
Current LE 1560
Segments 1
Allocation inherit
Read ahead sectors 0
Block device 253:0

--- Logical volume ---
LV Name /dev/VolGroup00/LogVol01
VG Name VolGroup00
LV UUID 42FZ1p-MOlf-ZLSl-5CyF-2QXK-YXBl-pzRODl
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 0
Block device 253:1

[Heironimus]

What you're missing is that logical disks in the ACU have absolutely nothing to do with LVM within the OS so you have to add the new space to your volume group to use it.

If fdisk already shows the new larger logical drive size you can create a new partition in that space of type 8e (Linux LVM). Run partprobe to notify the kernel of the change, pvcreate the new partition, vgextend on to it, lvextend the LV you need to grow, and ext2online to expand the filesystem to fill the LV.

If fdisk does not show the new size it probably means you haven't rebooted since you expanded the logical disk in the ACU. After a reboot you should see the new size.

It would probably have been better to create a new logical disk after expanding the array instead of expanding the existing logical disk. However, it should work either way.

[Daniele Di Salvo]

Thanks! It worked smoothly.

[Daniele Di Salvo]

The instructions given where exhaustive