Re: SAN Booting p-Series from EMC storage

john.mcconnell_at_jhmi.edu
Date: 06/10/05 

Date: 10 Jun 2005 07:46:04 -0700

We looked at doing this (not with EMC but with IBM Shark). The biggest
problem we had dealt with paths. Say you have 2 paths to your 2 root
disks that are on the SAN (independent adapters, switches, clusters).
Even though you mirror from one disk to the other... if you lose the
primary path AND have to reboot the partition it won't work. The
system would stay up but the reboot is the hitch... AIX looks for the
path... not the other hdisk (even though it's just sitting there ready
to go.)

One of my CE's suggested having an internal disk for rootvg and
mirroring to a SAN disk. This apparently isn't a problem (although
I've not tried it.)

I've had more than one CE and VAR advise me strongly "not to boot off
of the SAN." Having done AIX since 3.2... I still prefer the internal
disks.

John

aixd...@yahoo.com wrote:
> Nicholas Buckley wrote:
> > Hi everyone,
> >
> > I'm planning the migration of a p690 ( AIX 5.1 and 5.2 LPARs ) which is
> > SAN-attached to an EMC DMX 3000.
> >
> > Target platform will be p590 or p595
> >
> > At present all p690 LPARs boot from internal disks.
> >
> > We would like to move to SAN boot on the p59x
> >
> > Information from IBM and EMC confirms that SAN boot is supported in our
> > particular configuration.
> >
> > Whilst we will be working closely with both suppliers to effect a successful
> > move from internal disk to SAN boot, I was wondering it any list members
> > have any experience in this area which they would care to share.
> >
> > e.g.
> >
> > Have you done something similar recently ?
> >
> > Relatively straightforward, as implied by the suppliers, or fraught with
> > difficulty ?
> >
> > Any golden rules you discovered ?
> >
> > etc etc.
> >
> > Many thanks in advance - I'll be happy to relate our tale, once it's written
> > !
> >
> > Nick Buckley
> > Senior AIX System Engineer / Storage Manager
> >
> > ATRADIUS
> > Cardiff
> > UK
>
> NO, NO, NO, I wouldn't do it. "Supported" is a marketing term. "Working
> well" is another story. I have been doing AIX systems on EMC storage
> (Symmetrix and Clariion) for 11 years and have done upgrades, box
> migrations..etc many times.
>
> Here are my thoughts on booting from SAN. While it might work, I doubt
> it is worth the trouble. (classic risk vs reward).
>
> When you read through all the EMC Installation guides, release notes,
> README files, patch sets and all the other EMC doc required when
> installing/upgrading, you will notice a ton of "special procedures",
> workarounds, quircky items of all sorts surrounding booting from SAN.
> Seems like there are always gotcha's.
> (Just finished bringing all AIX systems to Powerpath 4.3 or 4.4)
>
> The EMC Powerlink Knowledgebase if full of past errors booting from
> SAN. If you notice, many ETA (EMC technical advisories) and alerts are
> related to booting off SAN.
>
> IMHO too many things have to be working to boot off SAN. (HBA's,fibre
> cables,SAN switches...etc) I prefer my system boot, because of it's
> criticality, to stay "close to home" (internal drive)
>
> Our standard has been 4 internal drives per system. One for AIX, a
> second for its mirror. The remaining two internal drives are for
> alt_disk and alt_disk mirrors (maintenance/upgrades.. etc)
>
> No IBM code on the SAN. No company data on internal drives. This has
> worked very well for us. If you are looking to bring in a p595, I doubt
> the cost of internal drives is much of an issue.

Relevant Pages

  • Re: Boot AIVX from EMC Clariion
    ... > We have several p670's that are SAN Attached to an EMC Clariion. ... SAN disk before attempting the installation. ...
    (comp.unix.aix)
  • Re: MSCS DR
    ... advice I am getting from EMC at this moment in time!!!!! ... One more thing if the geocluster we were planning is on the HCL would I ... have to dump the disk signatures as suggested earlier by Mark to get ... SAN array. ...
    (microsoft.public.windows.server.clustering)
  • Re: MSCS DR
    ... The kit is on the Windows HCL (EMC Clariion and Brocade) Is there a Geo ... Cluster HCL, can you point me to it? ... if you run dumpcfg.exe to document the current Disk signatures, ... SAN array. ...
    (microsoft.public.windows.server.clustering)
  • Re: SAN Booting p-Series from EMC storage
    ... > SAN-attached to an EMC DMX 3000. ... > At present all p690 LPARs boot from internal disks. ... > Information from IBM and EMC confirms that SAN boot is supported in our ... Our standard has been 4 internal drives per system. ...
    (comp.unix.aix)
  • Re: iseries and DS6000
    ... internal storage on an iSeries 820. ... dedicated SAN system like the DS6800... ... My idea is to have my production environment on internal drives ... Take care when adding disk in the ASP because this operation *may* have ...
    (comp.sys.ibm.as400.misc)