# cat /proc/mdstat 
Personalities : [raid6] [raid5] [raid4] 
md1 : active raid5 sdh1[0] sdb1[4] sde1[3] sdi1[2] sdd1[1]
      976783616 blocks level 5, 64k chunk, algorithm 2 [5/5] [UUUUU]
      
md0 : active raid5 sdf1[0] sdg1[2] sdc1[1]
      312576512 blocks level 5, 64k chunk, algorithm 2 [3/3] [UUU]
      
unused devices: <none>
# df -h /usr/share/media
Filesystem            Size  Used Avail Use% Mounted on
/dev/mapper/raidvg-media
                      200G  165G   36G  83% /usr/share/media
# time umount /usr/share/media

real    0m0.158s
user    0m0.002s
sys     0m0.002s
# time mount /usr/share/media

real    0m0.067s
user    0m0.001s
sys     0m0.003s