Dear group,

We are in the process of migrating our SAN platform to EMC Clarion
platform.
Currently we have Veritas Volume Manager installed, but since our data
volumes are quite stable it seems that we can drop Veritas VM and
perform the same operations with EMC native software.

For example Pwerpath can be used instead of vxdmp and hot swapping of
the box will be used instead of Veritas hotspares. Initial volumes
will be created large enough so no volume resizing may be needed in
the near future.

Can anybody share his experiences/best practices whether it is secure
to continue without Veritas VM on EMC Clarion and what added value can
Veritas VM bring to a stable SAN environment?


Thanks in advance,

Steve

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ist69@yahoo.com (Danny Stewens) wrote in
news:ef8f2320.0409280540.7a747f5c@posting.google.com:

> We are in the process of migrating our SAN platform to EMC Clarion
> platform.
> Currently we have Veritas Volume Manager installed, but since our data
> volumes are quite stable it seems that we can drop Veritas VM and
> perform the same operations with EMC native software.

You can do most of what Veritas can do with EMC software.

> For example Pwerpath can be used instead of vxdmp and hot swapping of
> the box will be used instead of Veritas hotspares. Initial volumes
> will be created large enough so no volume resizing may be needed in
> the near future.

The only thing you'll miss without Veritas is shrinking file systems
(assuming your OS has a way of growing it's native file systems).

> Can anybody share his experiences/best practices whether it is secure
> to continue without Veritas VM on EMC Clarion and what added value can
> Veritas VM bring to a stable SAN environment?

We run lots of hosts, windows and unix, with and without veritas (for sun),
with or without powerpath (vxdmp, hp-ux pvlinks and tru64 advfs works just
fine and the latter two come with the os) and we have very few problems.

Do make sure you follow the white papers on interoperability with all the
different OS's - the configuration of the clariion varies quite a bit from
platform to platform.

--
/Jesper Monsted

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Keep in mind that EMC recommends client side striping when you have a
filesystem that you would span across multiple raid groups (as opposed
to using meta-luns on the Clariion).  It seems that IO processes thread
better this way.  You can probably use a free volume manager that comes
with your OS, or powerpath 4.0+ to do this.  The stripe size of your
volume should be equal to the sum of the stripes on your raid groups,
so that a full stripe is written to each raid group.

There is a host CPU cost associated with doing this, so if you're more
concerned with this than IO throughput, then you may want to use
meta-luns after all.  Also, you can use meta-luns if there isn't a
volume manager available on your host capable of a custom stripe size.
HTH
Aaron

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The EMC solution is locking you into that hardware.

The Veritas software is a bit more flexible in that it will run on just
about any hardware; storage or host.

That may not be an issue for you. Just another perspective.

Cheers
Dean

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