[Lustre-discuss] Hardware Question

[Peter Avakian]

If the intention is not size, but to spread your I/Os on as many spindles as
possible, you could still have these volume groups.  Once you create these
volumes, you could have them sliced into multiple LUNs where their
collective sizes are acceptable by EXT3. 

Regards

-Peter

 

From: lustre-discuss-bounces at clusterfs.com
[mailto:lustre-discuss-bounces at clusterfs.com] On Behalf Of Aaron Knister
Sent: Wednesday, October 17, 2007 7:30 PM
To: Andreas Dilger
Cc: lustre-discuss at clusterfs.com; Lundgren, Andrew
Subject: Re: [Lustre-discuss] Hardware Question

 

So if I have arrays with 15 drives in them should I just configure two
smaller arrays? Also if I make a giant 30 terabyte filesystem of underlying
say 6TB disk arrays and one of my disk arrays bites the dust what happens to
the rest of the filesystem and how easy is it to recover from this
situation?

 

-Aaron

 

On Oct 10, 2007, at 11:48 AM, Andreas Dilger wrote:





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.

 

 

Aaron Knister

Associate Systems Administrator/Web Designer

Center for Research on Environment and Water

 

(301) 595-7001

aaron at iges.org

 





 

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