I'm working in a lab that generates a good amount of data and we've just about filled our 9.1TB RAID.
The system is a Dell PowerEdge 2950 running Scientific Linux 5.4 with a PERC H800 and a Dell PowerVault MD1200. The MD1200 has 12 bays, 6 of which were filled with 2TB drives that made up the original 9.1TB RAID5.
Recently, I purchased 6 new 2TB disks and added them to the 6 empty bays in the MD1200. Then, using Dell OpenManage, I reconfigured the virtual disk, adding the 6 new disks and converting to RAID6. That process took about two weeks and I ended up with about a 18.2TB virtual disk.
Now, the problem I'm having is expanding the volume group, which is still 9.1TB. I'm using the system-config-lvm package. The physical partition with all of my data is /dev/sdb1 and the volume group is called vg-home.
When I select 'vg-home Physical view' it shows me the volume group and a button below it that says 'Extend Volume Group'. I click on that button and a new window (title 'Extend Volume Group') pops up. In this window, one of my choices is /dev/sdb 9312.50GB Uninitialized Disk Entity. The only other choices are my non-LVM /boot and / partitions, /dev/sda1 and /dev/sda3. My understanding is that the uninitialized disk entity on /dev/sdb is all of the newly added, non-LVM disk space.
However, once I click OK, I get a warning that states "All data on disk entity /dev/sdb will be lost! Are you certain that you wish to initialize it?". Unfortunately, I don't have a test system so I want to be absolutely sure I'm doing this correctly. Is this uninitialized disk entity the new space? Does the warning mean that I'll lose the data on the LVM partition /dev/sdb1 as well or is it just saying that, if there is any data in the uninitialized space, it will be erased?