I am installing a 48T Dell MD-1200 and I was curious about this question. The MD1200 is connected to a hardware RAID card set up as RAID-6, so it looks to Linux like just a (big) drive. I tested an XFS filesystem on an LVM physical volume vs. an XFS filesystem on a straight disk partition. I used a Dell R630 machine with two E5-2699 CPUs in it. The system was set for Performance; whatever energy saving features I could find in the BIOS were turned off.
I installed CentOS 6.7 on it. Kernel is 2.6.32-573.el6.x86_64 (sorry for the oldie kernel but that's what I need for production). LVM is version 2.02.118.
I let CentOS create an XFS partition during the build. It is 1T in size. Then I created another 1T partition on the disk and created a logical volume:
vgcreate vol_grp1 /dev/sdb1
lvcreate -l 100%FREE -n lv_vol1 vol_grp1
My XFS-only filesystem was called
/data_xfs. The LVM-backed XFS filesystem was called
/data_lvm. I tested using bonnie++ v 1.03e.
The commands were:
bonnie++ -u 0:0 -d /FILESYSTEM -s 400G -n 0 -m xfsspeedtest -f -b where FILESYSTEM was either /data_xfs or /data_lvm .
Results are summarized as follows:
Test XFS on Partition XFS on LVM
Sequential Output, Block 1467995 K/S, 94% CPU 1459880 K/s, 95% CPU
Sequential Output, Rewrite 457527 K/S, 33% CPU 443076 K/S, 33% CPU
Sequential Input, Block 899382 K/s, 35% CPU 922884 K/S, 32% CPU
Random Seeks 415.0 /sec. 411.9 /sec.
Results seemed comparable in my view. In the Sequential Input test, LVM actually seemed to perform a little better.