[CentOS] XFS on a 25 TB device

Wed Sep 29 16:02:00 UTC 2010
Boris Epstein <borepstein at gmail.com>

On Wed, Sep 29, 2010 at 11:53 AM, James A. Peltier <jpeltier at sfu.ca> wrote:
>
> ----- Original Message -----
> | On Wednesday 29 September 2010, Boris Epstein wrote:
> | > Hello all,
> | >
> | > I have just configured a 64-bit CentOS 5.5 machine to support an XFS
> | > filesystem as specified in the subject line. The filesystem will be
> | > used to
> | > store an extremely large number of files (in the tens of millions).
> | > Due to
> | > its extremely large size, would there be any non-standard XFS
> | > build/configuration options I should consider?
> |
> | I have created and tested filesystems larger than 25T using xfs on
> | CentOS-5
> | (64-bit). I did not use any non-standard options. Do not attempt this
> | on a
> | 32-bit box.
> |
> | However, given the size of the device I assume that this is a raid of
> | some
> | sort. You'll want to make sure to run mkfs.xfs with the proper stripe
> | parameters to get the alignment right. Also, you may want to make sure
> | your
> | LVM or partition table is properly aligned.
> |
> | Even with the above done right you may get worse performance than
> | expected
> | since "lots of small files" typically reads like "terrible
> | performance".
> |
> | Finally I'd suggest you fill the filesystem and read it back
> | (verifying what
> | you wrote). This is, imho, a reasonable level of paranoia.
> |
> | /Peter
> |
> | > Thanks.
> | >
> | > Boris.
> |
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>
> On my 30+TB file systems all I've done is mkfs.xfs with stripe and width parameters and they are very speedy.  I've not done anything on the LVM side and see no performance issues, but perhaps I need to investigate that some more. :\
>
> --
> James A. Peltier
> Systems Analyst (FASNet), VIVARIUM Technical Director
> Simon Fraser University - Burnaby Campus
> Phone   : 778-782-6573
> Fax     : 778-782-3045
> E-Mail  : jpeltier at sfu.ca
> Website : http://www.fas.sfu.ca | http://vivarium.cs.sfu.ca
> MSN     : subatomic_spam at hotmail.com
>
> Does your OS has a man 8 lart?
> http://www.xinu.nl/unix/humour/asr-manpages/lart.html
>
>
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Thanks James!

I am wondering if I need to worry about stripe and width though as
mine resides on a logical volume residing on a hardware-controlled
RAID 6 device (i.e., one slice as far as the OS is concerned).

Boris.