Re: su,sw suboptions clarification on fs creation

[Joshua Baker-LePain <jlb17@duke.edu>]

On 30 Jan 2003 at 4:12pm, Dragos Delcea wrote

> given a recent linux distribution (SuSE 8.1) and a raid 0 logical disk
> (hardware raid with stripe=16k) with 3 scsi disks, what are the right
> parameters used at fs creation?
> I used:
> 
> #mkfs.xfs -l logdev=/dev/sda3,size=32768b -d \
> su=16384,sw=49152,unwritten=0 /dev/sdb1 -f;
> 
> but I have doubts about sw suboption, in the man page of mkfs.xfs the
> explanation seemd clear at first, but (I'm not an native english
> speaker) the more I stare at it, the more confused I get. Should it be
> sw=(su*number_of_disks)=49152, or sw=number_of_disks=3?

Given my reading of the man page, I think you are correct that sw should 
be 3.

Your other option is to use sunit and swidth switches, which are 
alternatives to su and sw.  These are specified in 512-byte units, and for 
your setup would be sunit=32768,swidth=98304.

-- 
Joshua Baker-LePain
Department of Biomedical Engineering
Duke University