Re: testing raid 0

[Greg Oster <oster@cs.usask.ca>]

On misc@openbsd.org <alx2001@medimex.ro> said:
> Hi, 
> I've succesfully configured raid 0 using raidctl on tow hdd (non SCSI; wd)
> So I went to the next step of testing but I'm disappointed in the
> improvement. Actually it's not an improvement is a loss, I think. Take a
> look below:
> 
> bash-2.05# mount
> /dev/raid0c on /mnt type ffs (local)
> 
> bash-2.05# pwd
> /mnt
> bash-2.05# dd if=/dev/zero of=a.file bs=10m count=15
> 15+0 records in
> 15+0 records out
> 157286400 bytes transferred in 20 secs (7864320 bytes/sec)

What does 'disklabel raid0' say?  Are wd0 and wd1 on the same IDE channel?  
What types of drives are they?  You report the speed for wd0, but not for wd1.
Is wd1 as fast as wd0?  How fast are reads?  Does wd1 have any hardware 
problems?  What type of machine is this?  ('dmesg' output would be useful here 
too..)  What are the filesystem parameters for / ?

> bash-2.05# pwd
> /
> bash-2.05# dd if=/dev/zero of=a.file bs=10m count=15
> 15+0 records in
> 15+0 records out
> 157286400 bytes transferred in 9 secs (17476266 bytes/sec)
> bash-2.05# 
> 
> Hmmm is this a raid ??? or what is it?
[snip]
> 
> My raid.conf looks like:
> START array
> 1 2 0
> 
> START disks
> /dev/wd0i
> /dev/wd1j
> 
> START layout
> 32 1 1 0

If you rebuild this set, bump the 32 to a 64.. that should help some too.
(but this sounds like there are other problems somewhere..)
 
> START queue
> fifo 100 
> 
> What can I make to work around this problem. I have openbsd29 current.

Dunno yet, as a bit more info is needed..

Later...

Greg Oster