Mailing List CGatePro@mail.stalker.com Message #92668
From: Martin.Hepworth <martinh@solidstatelogic.com>
Subject: RE: Filesystem layout and CGP performance
Date: Thu, 20 Sep 2007 09:17:49 +0100
To: CommuniGate Pro Discussions <CGatePro@mail.stalker.com>
X-Mailer: CommuniGate Pro MAPI Connector 1.2.12/1.2.12

I've bad experiences with ext3, both on the desktop and server.

IF you want a proper filesystem then XFS is the way to go.

A lot of the sys admins I know swear by ext3 and some swear at it, so YMMV as they say. (I had one of my friends who's use ext3 for years with no issues then 2 weeks spent 3 days fighting to repair a ext3 filesystem when it went wrong!).

A lot of filesytems in *unix start to degrade performance whise when they hit 90% usage.


Also you don't mention what the mailboxes are stored as, mbox or mdir - this can have a big impact too.

--
Martin Hepworth
Snr Systems Administrator
Solid State Logic
Tel: +44 (0)1865 842300

> -----Original Message-----
> From: CommuniGate Pro Discussions [mailto:CGatePro@mail.stalker.com] On
> Behalf Of Christian Ellsworth Capo
> Sent: 20 September 2007 03:33
> To: CommuniGate Pro Discussions
> Subject: Re: Filesystem layout and CGP performance
>
> Jorge R. Macías L. wrote:
>
> 8<------------------------------------------------------------------------
> ------
> > volume group formed with 5 FC 10Krpms 300 GB disks on RAID 5, the last
> > one on a similar volume group but with 15Krpms disks.
> >
> > Should I keep on using ext3?  Should I keep on using Redhat Enterprise
> > 4? Do I upgrade to Entreprise 5?  Do I use any specific parameters for
> > the kernel or for ext3 when I format the partitions in order to get a
> > better performance?
> >
> > Any suggestions?
> Well Jorge... let me see if i can be of help
>
> Filesystem:
> Ext3 is a very stable filesystem, not the absolut fastest but in my
> "Point of View",but it is the best relation in performance/data
> integrity/support/tunning.
>
> - EXT3 and many other filesystems beyond 90% of usage starts to have a
> performance hit. over 95% the IOwait levels of the OS are Skyhigh.
> Always keep at least a 20% free of the filesystem... it will help -trust
> me-.
>
> -To make EXT3 faster you can play with a couple of mount parameters and
> some kernel flags.
> in the mount options for each filesystem add: "noatime" this will ease
> at least a 20% of your current IOp/s (linux is not wasting IO in
> updating the last time the file was accessed, communigate uses the
> account.info file for that.. so is safe to do this trick.) still check
> the "man mount" info about noatime.
>
> - The Kernel bootline you can use "elevator=deadline" in RHEL4 a kernel
> entry of my grub config is :
>
>     title Red Hat Enterprise Linux AS (2.6.9-55.0.6.ELsmp)
>             root (hd0,0)
>             kernel /vmlinuz-2.6.9-55.0.6.ELsmp ro root=LABEL=/
>     elevator=deadline
>             initrd /initrd-2.6.9-55.0.6.ELsmp.img
>
>     this will change the default kernel scheduller from CFQ to DEADLINE,
>     making the system a lot more responsive in heavy load environments.
>
>
> - Also check in the systems log about messages of not enough files...
> perhaps the OS needs a little extra tunning. of numbers of files open.
> (sysctl -a | grep fs.file-max) a heavy loaded systenm should have more
> that 131k  I use in the large cluster 256k. and tweak the networking too.
> - Using recyclable temp files, helps in the communigate standpoint.
> - If you have the filesystem space, lower the CGP threshold for indexing
> the mailboxes (it uses a little more space but saves IOp/s)
>
> Hardware:
> RAID5 is one of the slowest raid configurations, it doesn't sacrifice
> that much capacity but it's not fast. even in enterprise class storage
> systems.  the best performance would be a RAID10 (raid 1+0), this
> sacrifieces more capacity but you gain double the access speed, and
> better write times.
>
> I would recommend in the new storage switching away from RAID5 to
> RAID10. depending also on the FC HBA maker/model/driver, check the
> tunning posible in command queues (this is a lot more advanced. so don't
> do nothing that you are not sure how it will affect the system).
>
> my $0.02
>
> I hope it'll help you hold until the hardware is working.
>
> Christian Ellsworth
> >
> > Thanks and best regards
> >
> > Jorge
> >
> > #############################################################
> > This message is sent to you because you are subscribed to
> >  the mailing list <CGatePro@mail.stalker.com>.
> > To unsubscribe, E-mail to: <CGatePro-off@mail.stalker.com>
> > To switch to the DIGEST mode, E-mail to
> > <CGatePro-digest@mail.stalker.com>
> > To switch to the INDEX mode, E-mail to <CGatePro-index@mail.stalker.com>
> > Send administrative queries to  <CGatePro-request@mail.stalker.com>
>
>
> #############################################################
> This message is sent to you because you are subscribed to
>   the mailing list <CGatePro@mail.stalker.com>.
> To unsubscribe, E-mail to: <CGatePro-off@mail.stalker.com>
> To switch to the DIGEST mode, E-mail to <CGatePro-digest@mail.stalker.com>
> To switch to the INDEX mode, E-mail to <CGatePro-index@mail.stalker.com>
> Send administrative queries to  <CGatePro-request@mail.stalker.com>




**********************************************************************
Confidentiality : This e-mail and any attachments are intended for the
addressee only and may be confidential. If they come to you in error
you must take no action based on them, nor must you copy or show them
to anyone. Please advise the sender by replying to this e-mail
immediately and then delete the original from your computer.
Opinion : Any opinions expressed in this e-mail are entirely those of
the author and unless specifically stated to the contrary, are not
necessarily those of the author's employer.
Security Warning : Internet e-mail is not necessarily a secure
communications medium and can be subject to data corruption. We advise
that you consider this fact when e-mailing us.
Viruses : We have taken steps to ensure that this e-mail and any
attachments are free from known viruses but in keeping with good
computing practice, you should ensure that they are virus free.

Red Lion 49 Ltd T/A Solid State Logic
Registered as a limited company in England and Wales
(Company No:5362730)
Registered Office: 25 Spring Hill Road, Begbroke, Oxford OX5 1RU,
United Kingdom
**********************************************************************

Subscribe (FEED) Subscribe (DIGEST) Subscribe (INDEX) Unsubscribe Mail to Listmaster