[mythtv-users] RAID on Fedora Core 3?

[Paul Barker]

Hi

>Looks like my RAID5 arrays have crap performance - esp. the master
array.

OK here are the stats from my RAID5 setup with 4 X Seagate 160Gb Drives
(all masters):
Version  1.03       ------Sequential Output------ --Sequential Input-
--Random-
                    -Per Chr- --Block-- -Rewrite- -Per Chr- --Block--
--Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP
/sec %CP
gryffindor       1G 23157  83 43898  24 14863   8 17742  58 32670  10
369.4   2
                    ------Sequential Create------ --------Random
Create--------
                    -Create-- --Read--- -Delete-- -Create-- --Read---
-Delete--
              files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
/sec %CP
                 16  1598  98 +++++ +++ +++++ +++  1640  97 +++++ +++
4086  97
 
So I see the traditional high CPU on writes but reads are fast with
little overhead. Your figures do look worse than mine in places (mostly
in the small file tests, although you seem to be using much less CPU
time).
 
I'm not worried about the high write times as the volumes I have on the
array are mainly read. I host my music, digital picture and movie files
there.
 
For myth buffers and my db I have an XFS filesystem on a standalone
disk, and my OS is on a RAID 1 mirror on another 2 disks.
 
Just curious if you got any output in dmesg or /var/log/messages whilst
running. I didn't see anything but I'm guessing that if there were bus
timing errors that'd be where they'd be. Did you (dare) try running this
on the master and slave arrays at the same time ? I'm guessing it would
grind to a halt.
 
Regards
 
Paul
 



Paul Barker	 	
	

		
pbarker at ntlworld.com
IM: spookt2000 at yahoo.co.uk 	
		
	

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