[Lustre-discuss] Hardware Question

[Andreas Dilger]

On Oct 10, 2007  09:40 -0600, Lundgren, Andrew wrote:
> As RH 5.1 will support 16TB ext3 partitions, will lustre inherit that
> functionality? 

We haven't looked at this yet.  The ldiskfs code is ext3 + patches, so there
is some chance that it will work (more likely on 64-bit platforms), but
we haven't audited the ldiskfs patches to check if they are 32-bit clean.

> > -----Original Message-----
> > From: lustre-discuss-bounces at clusterfs.com 
> > [mailto:lustre-discuss-bounces at clusterfs.com] On Behalf Of 
> > Andreas Dilger
> > Sent: Wednesday, October 10, 2007 9:26 AM
> > To: Aaron Knister
> > Cc: lustre-discuss at clusterfs.com
> > Subject: Re: [Lustre-discuss] Hardware Question
> > 
> > On Oct 06, 2007  10:28 -0400, Aaron Knister wrote:
> > > Oh, right I forgot about that. Well...if i had an 8tb lun 
> > and split it 
> > > into 2 volume groups using LVM do you think the performance 
> > would be 
> > > worse than making 2 raids at the hardware level?
> > 
> > Well, it won't be doing the disks any favours, since you'll 
> > now have contention between the OSTs, and the kernel will be 
> > doing a poor job with the IO elevator decisions.  I would 
> > suggest making 2 smaller RAID LUNs instead.
> > 
> > In the end it is up to you to decide if the IO performance is 
> > acceptable.
> > You can do some testing using lustre-iokit to see what the 
> > component device performance is.
> > 
> > > On Oct 5, 2007, at 6:18 PM, Andreas Dilger wrote:
> > > 
> > > >On Oct 05, 2007  13:14 -0400, Aaron Knister wrote:
> > > >>Make that 6x 9.7TB luns.
> > > >
> > > >Lustre (== ext3) doesn't support >= 8TB LUNs.

Cheers, Andreas
--
Andreas Dilger
Principal Software Engineer
Cluster File Systems, Inc.