We have a 6 SSD, RAID5 volume. The SSD disks we are using are Crucial M4-CT512M4SSD2 firmware 000F. We write 100 ~ 200GB data through MySQL InnoDB to the volume daily. The RAID5 volume is only used for MySQL and nothing else.
Output of lsscsi:
[0:0:0:0] disk iDRAC LCDRIVE 0323 /dev/sdb
[1:0:0:0] cd/dvd iDRAC Virtual CD 0323 /dev/sr0
[1:0:0:1] disk iDRAC Virtual Floppy 0323 /dev/sdc
[2:2:0:0] disk DELL PERC H700 2.10 /dev/sda
[3:0:0:0] disk ATA M4-CT512M4SSD2 000F /dev/sdd
[3:0:1:0] disk ATA M4-CT512M4SSD2 000F /dev/sde
[3:0:2:0] disk ATA M4-CT512M4SSD2 000F /dev/sdf
[3:0:3:0] disk ATA M4-CT512M4SSD2 000F /dev/sdg
[3:0:4:0] disk ATA M4-CT512M4SSD2 000F /dev/sdh
[3:0:5:0] disk ATA M4-CT512M4SSD2 000F /dev/sdi
[3:0:6:0] enclosu LSI CORP SAS2X36 0717 -
[3:0:7:0] enclosu LSI CORP SAS2X36 0717 -
Output of smartctl : (see here for attribute 173)
for p in d e f g h i ; do smartctl -A /dev/sd${p} | grep 173 ; done
173 Unknown_Attribute 0x0033 098 098 010 Pre-fail Always - 67
173 Unknown_Attribute 0x0033 098 098 010 Pre-fail Always - 66
173 Unknown_Attribute 0x0033 098 098 010 Pre-fail Always - 71
173 Unknown_Attribute 0x0033 098 098 010 Pre-fail Always - 66
173 Unknown_Attribute 0x0033 098 098 010 Pre-fail Always - 69
173 Unknown_Attribute 0x0033 097 097 010 Pre-fail Always - 105
And the output for /proc/mdstat:
Personalities : [raid6] [raid5] [raid4]
md0 : active raid5 sdi[6] sdg[3] sdh[4] sdf[2] sdd[0] sde[1]
2500532160 blocks super 1.2 level 5, 64k chunk, algorithm 2 [6/6] [UUUUUU]
bitmap: 3/4 pages [12KB], 65536KB chunk
unused devices: <none>
We are unsure why "sdi" is more than 40% more worn out than other disks, as the parity should be evenly distributed across all disks.