Checking XFS file system

The other day, I tried to check a 7.5 TB XFS partition, after I upgraded the server hosting that particular partition from CentOS 5.7 to SL 6.1.  The partition was built from 6 drives of Linux MD RAID 5. So I ran
# xfs_check /dev/md0
and after a while, boom, the system killed the program because it ate memory too much. Googling the issue informed me that xfs_check indeed required a lot, and I said it again, A LOT, of memory. However, after much googling, there was a resolution for this. Instead of using xfs_check, one could perform the equivalent functionality using
# xfs_repair -n /dev/md0
and without much memory to eat either (but still real slow).