Currently we are setting up and testing our new Oracle Linux environment.
I created on one of our VMWare (5.5) hosts a VM and installed Oracle Linux 6.5
Using LVM I created 1 basic Volume Group with the root partition and swap.
After I finished the installation I created an extra disk in VMware and created a new Volume Group containing the Oracle Logical Volumes and mount points.
Then I thought: this could better be a bit larger, so I extended in VMWare the second disk from 50GB to 100GB.
In the OL6-box I forced a SCSI rescan and with fdisk I first deleted /dev/sdb1 (size = 50GB) and in the same session created a new partition, size 100GB.
So far so good:
[root@koerlan 2:0:1:0]# fdisk -l /dev/sdb
Disk /dev/sdb: 107.4 GB, 107374182400 bytes
64 heads, 32 sectors/track, 102400 cylinders
Units = cylinders of 2048 * 512 = 1048576 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00000000
Device Boot Start End Blocks Id System
/dev/sdb1 1 102400 104857584 8e Linux LVM
Now the kernel has to be told that the partition has grown from 50 to 100GB.
As can be seen in /proc/partitions this is not yet the case:
...
8 16 104857600 sdb
8 17 52428784 sdb1
...
This should be fixed by using the partprobe command:
[root@koerlan 2:0:1:0]# partprobe /dev/sdb
Warning: WARNING: the kernel failed to re-read the partition table on /dev/sdb (Device or resource busy). As a result, it may not reflect all of your changes until after reboot.
But as you can see, this operations fails.
From other resources on the web I understood this is new to OL6, in OL5 it used to work, but was considerd an unsafe operation.
That leaves a few other options:
[1] I can reboot the system.
We are not a 24x7 shop, but even I think it very clumsy not te be able to extend a filesystem without rebooting the system.
[2] in stead of extending an existing disk I could create a new one. The kernel can see this new disk and I can then use it in LVM to add to an existing LV.
Which means that I will end up with lots of extra disks during the lifetime of the server. It's possible, but not what I want.
Coming to my question: is there really no other way to add an disk extension to an existing VG without rebooting the system or creating new disks?
Thanks,
Peter