For the fun of it, I ran dstat on my RHEL 5 server to check how even the disk usage was on the software RAID 5. I found it to be surprisingly even and efficient:
The server is primarily a webserver but also does e-mail routing, spamfiltering, storage, etc. Here’s the mdstat content:
green [imbrius@dustpuppy ~]$ cat /proc/mdstat Personalities : [raid6] [raid5] [raid4] md0 : active raid5 sdb2 sda2 hdc2 hda3 466503168 blocks level 5, 256k chunk, algorithm 2 [4/4] [UUUU] unused devices: <none>
I was very surprised at how even the disk usage was across the four members of the RAID-5 array. It seems that Linux’s mdraid software has really come a long way since I last saw it. Incidentally, I see better read performance out of this RAID-5 array than I did with my previous LVM-striping over two software RAID-1 arrays on the same hardware. A little slower write performance, though.