RE: advice: 3ware+raid+xfs

[Seth Mos <knuffie@xxxxxxxxx>]

At 21:42 14-1-2004 -0800, Mike Young wrote:
> Hi Gaspar,
>
> I would certainly be sure to use the external journal.  In order to do this
> with our 3Ware RAID-5, take the resulting RAID (say /dev/sda) and partition
> it with sda1 being around 256MB.  Then create sda2 using the rest of the
> data.

Using the external journal gives the most benefit on Linux software raid 
volumes.

Put the log on another partition on the same logical disk doesn't make 
sense to me.

My suggestions are using sunit=4096 and swidth=3 (n-1). You could use a 
larger stripeunit sizes but I don't remember helping it much. Besides that, 
using a 64k stripe will results in 192k total stripe size. You need to 
specify this on the mount command since the default mounts upto 64k in 
stripe size.

I tested this some months ago on a 6 disk configuration and the results did 
not differ much from the defaults.

Creating a larger log will help the filesystem if you perform a lot of 
operations on it. I create my larger filesystems this way. It helps a lot 
on the IOPS.

Cheers
--
Seth
I don't make sense, I don't pretend to either. Questions?