[linux-lvm] lvm2 on raid5 speed, not so bad

[Scott Serr]

Just to share some information...

Here is a "bonnie -s 1024" on a P4 2.4 with 512MB RAM.  The RAID5 is my 
weirdo way of doing multiple RAID5 devices so that I can move things 
around.  All 4 RAID5 meta devices are on the same 5 disks... 300GB SATA 
and (4) 200GB PATA drives.

LVM2 over RAID5
             -------Sequential Output-------- ---Sequential Input-- 
--Random--
             -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- 
--Seeks---
          MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU  
/sec %CPU
        1024 16987 69.9 34777  7.4 16659  4.1 21532 86.4 49760  9.2 
470.7  1.7


"Hot" SATA 300GB (Maxtor)
             -------Sequential Output-------- ---Sequential Input-- 
--Random--
             -Per Char- --Block--- -Rewrite-- -Per Char- --Block--- 
--Seeks---
          MB K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU K/sec %CPU  
/sec %CPU
        1024 23553 96.2 62613 14.0 26123  5.1 22094 87.5 57233  6.9 
200.9  0.4

Forgot to mention that the RAID5 devices are 1024k "chunk-size".  
Filesystem is reiserfs.

-Scott