Re: XFS filessystem for Datawarehousing

Hi Like, Mark , Alvaro and Andrew,

Thank you very much for sharing you experience with me.
I want to compare DHW performance of PG/Bizgres on different filesystems and difffrent
Block sizes.

The hardware will be free for me in a week or too (at a moment another project is running on it) and then I will test
diffrenet setups and will post the results.

I MUST (sorry, no other choice) use SLES6 R3, 64 bit. I am not sure at all that I will get enough budget to get
approapriate RAID controller, and that is why I intent to use software RAID.

I am pretty exited whether XFS will clearly outpertform ETX3 (no default setups for both are planned !). I am not sure
whether is it worth to include JFS in comparison too ...

Best Regards,
Milen Kulev

-----Original Message-----
From: Luke Lonergan [mailto:llonergan(at)greenplum(dot)com]
Sent: Wednesday, August 02, 2006 4:43 AM
To: Milen Kulev; pgsql-performance(at)postgresql(dot)org
Subject: Re: [PERFORM] XFS filessystem for Datawarehousing

Milen,

On 8/1/06 2:49 PM, "Milen Kulev" <makulev(at)gmx(dot)net> wrote:

> Is anyone using XFS for storing/retrieving relatively large amount of
> data (~ 200GB)?

I concur with the previous poster's experiences with one additional
observation:

We have had instabilities with XFS with software RAID (md) on 32-bit Xeons running RedHat4 U3 with the Centos 4.3
unsupported SMP kernel. XFS would occasionally kernel panic under load.

We have had no problems with XFS running on the same OS/kernel on 64-bit under heavy workloads for weeks of continuous
usage. Each server (of 16
total) had four XFS filesystems, each with 250GB of table data (no indexes) on them, total of 16 Terabytes. We tested
with the TPC-H schema and queries.

We use the default settings for XFS.

Also - be aware that LVM has a serious performance bottleneck at about 600MB/s - if you are working below that
threshold, you may not notice the issue, maybe some increase in CPU consumption as you approach it.

- Luke