vinum in 4.x poor performer?

[Marc G. Fournier]

On Wed, 9 Feb 2005, Mark A. Garcia wrote:

> Marc G. Fournier wrote:
>
>> 
>> Self-followup .. the server config is as follows ... did I do maybe 
>> mis-configure the array?
>> 
>> # Vinum configuration of neptune.hub.org, saved at Wed Feb  9 00:13:52 2005
>> drive d0 device /dev/da1s1a
>> drive d1 device /dev/da2s1a
>> drive d2 device /dev/da3s1a
>> drive d3 device /dev/da4s1a
>> volume vm
>> plex name vm.p0 org raid5 1024s vol vm sd name vm.p0.s0 drive d0 plex vm.p0 
>> len 142314496s driveoffset 265s plexoffset 0s
>> sd name vm.p0.s1 drive d1 plex vm.p0 len 142314496s driveoffset 265s 
>> plexoffset 1024s
>> sd name vm.p0.s2 drive d2 plex vm.p0 len 142314496s driveoffset 265s 
>> plexoffset 2048s
>> sd name vm.p0.s3 drive d3 plex vm.p0 len 142314496s driveoffset 265s 
>> plexoffset 3072s
>> 
>> bassed on an initial config file that looks like:
>> 
>> neptune# cat /root/raid5
>> drive d0 device /dev/da1s1a
>> drive d1 device /dev/da2s1a
>> drive d2 device /dev/da3s1a
>> drive d3 device /dev/da4s1a
>> volume vm
>>  plex org raid5 512k
>>  sd length 0 drive d0
>>  sd length 0 drive d1
>>  sd length 0 drive d2
>>  sd length 0 drive d3
>> 
> It's worth pointing out that your performance on the raid-5 can change for 
> the better if you avoid having the stripe size be a power of 2.  This is 
> especially true if the (n)umber of disks are a 2^n.

I read that somewhere, but then every example shows 256k as being the 
strip size :(  Now, with a 5 drives RAID5 array (which I'll be moving that 
server to over the next couple of weeks), 256k isn't an issue?  or is 
there something better i should set it to?

----
Marc G. Fournier           Hub.Org Networking Services (http://www.hub.org)
Email: scrappy at hub.org           Yahoo!: yscrappy              ICQ: 7615664