Hello Managers !
A late summary, but an informative one, I hope. My original post is at the
end. Thanks to Knut Hjelleboe [I deleted your message accidently, but I've
at least red it, sorry :-( ], M. Luchini, R.Carsey, J.Harvey, and our
proposed vendor.
So I've learned that UFS IS NOT UFS, at least at the physical representation
layer. We can't simply read a SUN partition on a DEC and vice versa (even
if the same structures would be used, they'd be byte-swapped....). Only one
System can do this --- LINUX! (at least for Sun, BSD, SCO, Coherent,.....).
But FCAL drivers for Linux have even not been discussed yet :-< .
Therefore it follows that you can spread filesystems from any system
over your RAID disk arrays, but they are, in the first place, confined
to their OS. What is possible today (at the operating system level) is
to export these partitions to the other systems via NFS, which has to
go (up to now) over traditional ether-or gigabit net. Even though StorageWorks
runs on different OS, it cannot provide mixed access. Only some applications
are able to read their own formats on different OS, like Oracle.
Luckily, there's light at the end of the tunnel. Our vendor confirmed
rumours that Compaq and Sun are working on solutions to use FCAL for
more than just accessing raid systems. The controllers will be capable
of having some ethernet functionality or at least, memory channel -like
transport mechanisms. Given that, it should be possible to implement
NFS exports over the FCAL - controllers and switches to circumvent the
ugly practice doing this over a second, slower network card. Anyway,
we have no definite answer how long these improvements will take and to
what extend these functionalities can be exploited. May some Compaq
technician reading this has more details (please post !).
Additional drivers for foreign filesystems -- as Linux provides -- are not
planned (as far as I was able to find out).
One flaw currently imposing difficulties is that Sun only supports FCAL
hubs, but Compaq only switches. But Sun is working on that topic, they
claimed to have a solution next month. The second one is that Compaq
switching is currently limited to as much FCAL initiators as are ports
available, so you can't plug 5 four processor machines with 1 or 2 FCAL boards
each to a 16-port switch. But this is just a firmware limitation and will be
overcome soon.
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>From Marco.Luchini_at_acco-uk.co.uk Mon Oct 4 18:19:00 1999
Surely he's referring to the fact that the Unix file system is not
universal. So a DEC can't read a Sun UFS filesystem and viceversa. That
issue is unrelated to the storage medium. You'd have the same problem if
you took a single SCSI disk from a DEC and physically connected it to a Sun.
Marco
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>From rcarsey_at_monmouth.edu Mon Oct 4 19:40:23 1999
Hmm.. if the ES40 and the SUN both use UFS -- UFS is UFS is UFS right? And
the HSG is just a RAID controller like any other RAID controller.. Shame on
Compaq or SUN for not using a standard UFS if that is the case..
Make sure to post a summary, I'm curious as to know the answer to this one..
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>From jharvey_at_eccnet.eccnet.com Tue Oct 5 20:27:08 1999
Now, I understand a bit more.. When you set up your ESA12000 raid sets
you must tell the HSG80 what type of system will be accessing each raid
set (i.e. unix, VMS or NT), you must also tell it which nodes (viable on
the SAN) will have access to each volume that you create. In a Unix
environment, (T64 Unix may be different in V5.0) only one system may
actually mount a given Volume at any one time. (File access conflicts,
etc.) Any other system must access the mounted volume through the one
system that actually has it mounted. If a part of a T64Unix cluster, this
can be done via the memory channel which is very fast. otherwise something
such as NFS, must be used. If the system that has the volume mounted
releases it ( umount) then any other system that is defined y the HSG80 to
have access may then mount it directly. Other than in a clustered
environment of like architectures, file structure issues would come into
play. Sun could not read an advfs file system. I don't know if a UFS
formatted Volume (formatted under digital unix) would or would not be
readable by Solaris.
Raw file systems such as those used by Oracle Parallel server can be
accessd by more than one system but only under control of the Oracle
application.
I hope this helps a little.
John F. harvey
Digital UNIX ASE
Electronic Commerce Connection, INc.
Jharvey_at_eccneet.com
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ORIGINAL POST:
==============================================================================
On Mon, 4 Oct 1999, Udo Grabowski wrote:
> Hello Managers !
>
> We have to buy a 2+ TB Esa 12000 FC-AL array, which must be
> connected to our ES40 AND to some SUN-boxes via 4 HSG80
> controllers. Our vendor now informed us that a technician
> from Compaq said our Suns may will not read the files written
> by the ES40 and vice versa because of some inconsistencies
> in the filesystems on the array. Has anybody heard about
> that ? Is there someone out there who runs a similar
> configuration successfully ? Is this problem only bound to
> RAID configurations ?
> Any information would be helpful !
> regards,
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> Dr. Udo Grabowski email: udo.grabowski_at_imk.fzk.de
> Institut f. Meteorologie und Klimaforschung II, Forschungszentrum Karslruhe
> Postfach 3640, D-76021 Karlsruhe, Germany Tel: (+49) 7247 82-6026
> http://www.fzk.de/imk/imk2/ame/grabowski/ Fax: " -6141
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Received on Thu Oct 21 1999 - 12:45:32 NZDT