From: John Gormley (jgormley@scu.edu.au)
Date: Sun Sep 07 2003 - 23:33:13 EDT
Apologies for the late summary, many thanks to the respondents:
Greg Rudd
Martin Petder
Alan Davis
Raul Sossa
Original question, followed by responses:
Hi Managers,
> I sent out an e-mail a coupla weeks back regarding pros and cons of
> SANS and peoples experiences, which I summarised and reposted. Now
> that I am becoming a bit more SAN savvy, I would like to drill a bit
> deeper and more specifically into peoples SAN experiences. I am at a
> bit of a gridlock between an HDS system and the HP EVA3000. I am
> interested in any problems people have had with EVA systems and any
> good/bad experiences with the Managemant Appliance and software on
> EVA's e.g levelling operations, snapshot etc. I really like the look
> of the virtualisation and the ease of use of the Management software,
> but have heard a couple of problems.
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Martin Petder:
There were a _lot_ of problems in the beginning of EVA, but they were
resolved with EVAv2. EVAv3 is now out and aside
from replication service (which is brand new software for EVA, waiting
for it's first "service pack" to be available in the end of this year)
everything is working correctly. We have multiple installations of
EVA5000 and have had no problems since upgrading to EVAv2.
Now about EVA3000 - it's a midrange product, as is HDS Thunder series.
Aside from the virtualization architecture, which is really awesome
(would you really use small RAID groups from small number of disks when
you can use _all_ your disks for all applications? :) the two storages
look quite similar. If you would have any funds I would really suggest
going for EVA5000 - because of it's switched back-end. You can quite
safely do tricks like pulling out whole shelf full of disks without
losing your data (and even not losing a lot of perfomance :) and also
easily upgrade your system because of that.
EVA3000 is running the same software than 5000 series, only about a
quarter later. It's already running EVA software version 2, which is a
good working solution - and will be running version 3 next month. If you
want to use replication I would suggest waiting for december when the
next software upgrade (with bugfixes) arrives.
Snapshot and snapclone operations are running fine on EVA - with all
operating systems (have tried with Solaris, Tru64, Windows and Linux).
(Remember you can't do online copy of your data with HDS, that would
survive the loss of original data RAIDset). Nowadays EVA's are also
bundled with Enterprise Volume Manager, which is an graphical scripting
front-end for logical and physical cloning and what can be used together
with your favourite backup software. Also command line management of EVA
is quite easy and similar to digital's HSG controller series.
Automatic levelling in EVA is done only when controller is idle (i.e. no
serious host activity) - and you almost won't notice it aside from your
data access to get gradually (and _slowly_ :) faster.
Biggest problem might be seen with Management Appliance (which was also
very buggy in it's first versions, but is working correctly now) - what
is a MS Windows server in enterprise environment :)
Same time Management Appliance is in no way required for the operation
of the EVA - if it breaks or crashes you can safely reboot or reinstall
it whenever you feel the need. Only thing you would loose is your event
logs (beside what is being kept also in EVA) and maybe a little time of
inserting installation CDis into the appliance. Actually there is even
quite strong rumour going around about development of the stand-alone
version of management software for EVA - so you wouldn't even need
Management Appliance.
HDS also has it's set of problems - especially on the thunder series
(and somehow I doubt you are choosing between EVA3k and Lightning :) For
example they do not fully support multiple-level RAID partitions (i.e.
0+1, 10, 0+5 and so on) - as some things (for example replication) are
not possible with these RAID levels. Also during replication HDS Thunder
is not doing write history logging, thus giving you possibility to
seriously corrupt your filesystems and database in replicated area :)
For simple operations (i.e. for disk serving) HDS is solid and good
product - as is EVA.
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Alan Davis
I have 3 EVA5000 cabinets running 24T. They were installed in October last
year and have been /very/ easy to manage. The user interface via the web is
ok for small tasks and SSSU is adequate to handle large reconfigurations. I
use SSSU to capture nightly configs in both restorable and scriptable forms
and to reconfigure storage if I'm doing more than a disk or two.
I've had a couple of disks fail out with the system "doing the right thing"
in every case. No downtime, no data loss.
The message/alert mechanism is somewhat cumbersome - HP has promised that
the integration with the HP OpenView products will solve that.
The only complaint that I have is that there's currently no way to ask the
HSV controllers for performance statistics like you could with the HSx VTDPY
display.
I would like to know more about how to handle catastrophic failures... Our
computer room was destroyed in Oct in a flood but we recovered all but 4 of
500+ drives from the ESA12000 system because we knew what disks held the
data. With the virtualization of the EVA the controller knows where the data
is, but it can't tell you.
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Raul Sossa
During last two years We've been supporing about 4 EVA5/3000's locally in
Costa Rica,
Central America.
It's been a very interesting experience and our customer are now really
full-satisfied with this machines. EVA5/3000 it's really faster and the most
Heterogenous Storage I've seen before.
One of our bigger customer has an Enterprise Backup Solution using hp
Business Copy Software 2.1a and the Snapclones and Snapshots capabilities.
They have a 6TB storage system and and Oracle Production Database that is
normally and clearly backed up in less than 7 minutes using the
Virtualization Technology of these products.
The Snapshots and Snapclones implementation of the EVA's is really the best
way we can take a picture of your BIG DATA, startup your services and wait
for clone background
to be process (but your date is transactionally stable).
Falt Tolerance and Dynamic Expansion is pretty cool, also.
Adittionally, remember that EVA3000 just grows to 58 disk drives and EVA500
grows to 240 Disk Drives.
EVA3000 y just like an EVA5000 but without the additional disk drives and
the Continuous Access option Disabled.
Note that EVA3000 can not use the VCS 3.0 (by now I guess), it is only
available to use the VCS 2.0a, wich obviusly is not able to implement Disk
Remote mirroring for your future/possible dister recovery solution).
I suggest you this site to check for SAN Issues:
http://h18000.www1.hp.com/products/storageworks/san/documentation.html
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Greg Rudd
During a leveling operation our machine just shut down and didnt come back
up again
the hsv110 appeared to have totally lost its config. As an aside We have
just received our disks back from the US and apparently they have recovered
the data. Hopefully the will have some real answers for us.
In response to prompting re virus protection for the Windows O/S Management
Appliance, Greg answered:
What we have done with the appliance is put it behind a firewall and then we
only allow 1 trusted ( non M$oft machine) machine to talk to it.
Regards, John
John Gormley
Senior Unix Systems Administrator
Information Technology and Telecommunications Services
Southern Cross University
Lismore NSW 2480
AUSTRALIA
Office :(02)6620 3365
Mobile: 0409 150060
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