I am running RHEL6.4 and am tasked with creating a block device large enough to hold a 100TB filesystem. The storage unit I am using is a 3Par and it is restricted to LUNs up to 16TB in size.
I have created seven 16TB LUNs and need to join them together in RHEL6.4. Which is the best approach?
Should I use mdadm to create a LINEAR device and then put an XFS filesystem on top, or should I just use LVM to create a large volume out of the 3Par LUNs and then put an XFS filesytem on top of it.

Also, I have some questions regarding handling of the 3Par LUNs.
Do I need to add a GPT partition to these 16TB LUNs prior to using them in LVM or MDADM or should I just use the entire devices with no partition table?

I have already tried 3par --> MDADM --> XFS approach but encountered the following message "warning: device is not properly aligned /dev/md0. use the -f option to force ..." How do I properly align the filesystem with the MD device? Thanks for your help.

I always found the {md,dm}raid solution too fiddly - only used it when coerced. So take the following for what it's worth.

For a linear, I would think LVM more straight-forward - always been excellently supported on RHEL. Even has a GUI.
Personally I prefer to just pvcreate on the device when I have the opportunity - messes with the minds of some people though. Shouldn't matter either way, but I've never tried on something that big.

http://forum.nas-central.org/viewtop...?f=240&t=14145 offers clue to fault.

Huh, fsck'ing 100T will take some time...
My vote for ZFS instead of LVM/otherFS.

I ran write tests with Linear LUNs created with MDADM and LVM and found that the LVM LUNs performed better and more consistently.