UFS2 with SAN

[Nicole Harrington]

--- Eric Anderson <anderson at freebsd.org> wrote:

> On 02/10/07 00:54, Chris Haulmark wrote:
> > 
> >> -----Original Message-----
> >> From: Eric Anderson [mailto:anderson at freebsd.org]
> >> Sent: Saturday, February 10, 2007 12:48 AM
> >> To: Chris Haulmark
> >> Cc: freebsd-fs at freebsd.org
> >> Subject: Re: UFS2 with SAN
> >>
> >> On 02/09/07 19:30, Chris Haulmark wrote:
> >>> Hello,
> >>>
> >>> I am looking into setting up a SAN with several
> web servers that
> >>> will be clustered.  It would be a FC network
> using Qlogic cards
> >>> in each of those FreeBSD web servers.  It would
> be about 5+
> >>> of those web servers.
> >>>
> >>> I want to have the capability to share the same
> web data across
> >>> those web servers.  I have scorched the entire
> mailing list and
> >>> found that there were some work on GFS porting
> over to FreeBSD.
> >>> It seems like that it is just all talk and if I
> am wrong, could
> >>> you have my head turned over to where I can find
> out how to enable
> >>> GFS on those FreeBSD systems.
> >> GFS on FreeBSD is indeed dead.  Not enough people
> stepped up to help
> >> port it.
> > 
> > I really feared to hear that!
> > 
> >>> If GFS is out of question, which file system am
> I recommendeded
> >>> to attempt to use for this SAN setup?
> >> NFS.
> >>
> >>> My first thought to use UFS2 and attempt is to
> allow only one web
> >>> server to have a write/read access while the
> reminder would be
> >>> read only access. That should prevent from
> lockings that is similar
> >>> on NFS/NAS.
> >> This will result it the read/write system seeing
> the data ok, and the
> >> rest getting corrupt data without knowing it, and
> probably crashing.
> >> UFS2 is not cluster aware.  You could mount all
> the hosts read only,
> >> and
> >> then update the mount point on one to rw, makes
> changes, then back to
> >> ro, then unmount/remount on the other boxes.
> > 
> > That's my original idea if I do not have anything
> else better to go
> > with.
> > 
> >> That's all still a kludge to simulate what NFS
> will do for you.  Why
> >> won't NFS work for you?
> > 
> > I have a client who wants to go from NAS to a true
> SAN solution with
> > full
> > fibre channel network.  I would hate to lose the
> opportunity for this
> > client
> > to continue using FreeBSD as the choice of OS for
> his web servers.
> > Currently,
> > his set up is using NAS with NFS.  He complains of
> locking files that
> > occurs
> > too often.
> > 
> > I had hoped to find more better solution and make
> this client much more
> > happier
> > with all the FreeBSD support that can be provided.
> 
> 
> Well, I'm not sure what issues they had, but have
> had fantastic success 
> with NFS and FreeBSD.  FreeBSD with the right
> hardware and tweaks can 
> make some NetApp boxes look weak. *cough* WAFL
> *cough*
> 
> 
> >> I agree that it would be fantastic to have a
> clustered file system for
> >> FreeBSD, and I've done lot's of hunting and
> nagging vendors to support
> >> it - but it's just not there.
> > 
> > We should get few bandwagons and get in circle. 
> It could be likely that
> > I could
> > provide access for the developers to test and get
> whatever file system
> > and other
> > necessaries needed to be working. :)
> 
> 
> The problem isn't the environment or hardware, it's
> developers skilled 
> to do the work.  They're all either in NDA's, off
> writing something 
> else, or just too busy to provide any amount of
> input.
> 
> Eric


I have a set of servers NFS mounted to a Netapp and
after hurs of tuning with netapp's help. (after
getting through the idiots adking what FreeBSd was)
 I got very low performance. I was of course then told
 by Netapp to switch to Linux for better NFS support. 

 I would love for any help with tuning this further,
but I cannot say that FreeBSD with Netapp NFS will be
great. Of course, I have not been able to test if
indeed Linux would be any better. 
 I will say however that I have a large number of
small files which tends to not do well with NFS. 
 

 Nicole