On Mon, Mar 22, 2004 at 02:31:16PM -0800, Mike Young wrote:
> Hi All,
> I'm running into a problem when I use the external journal option along with
> ACLs. Without ACLs, I can see a significant performance delta between the
> use of an internal journal and an external one. Under Netbench, the
> difference is as much 2x to 3x. So, I definitely want to use this
> capability. However, all of my testing was without ACLs being set. When I
> went back and turned ACLs, the performance turned upside down on me.
> Basically, the there is very little performance difference between internal
> or external journal. And, in some cases, the external journal is slower
> than the internal journal.
> Any tips on how I should configure the ACLs so as to not degrade
Use larger inodes -- ie. the mkfs.xfs option -isize=512 (or greater),
will allow the ACLs to be stored inline most of the time, and is a
large performance win for this sort of workload.
> To set the journaling up for external placement, I'm using "mkfs.xfs
> /dev/md1 -l logdev=/dev/md0,size=10000b". For ACLs, I'm just using getfacl
> to store the acls in a file till I can reapply them to the new directories
> using "setfacl -set-file".