SAN COnsiderations SQL Server

Hello All,
Looking at implimenting an enterprise SAN that will host approximately 17
applications (DB, Exchange etc...) and a LUN for storage of user data
(profiles etc...).
Approximately 40 TB or disk , effectively 20 due to a RAID 10 setup.
Any caveats with this setup?
The equipment is :
EMC CX3.
My main concern is that the disk real estate/LUN's dedicated to a given
server (SQL Server for instance) will have its own disk spindles/heads.
So if the Exchange Server is using the same SAN, but a different LUN, will
they share disk heads?
Your advice is warmly welocmed.
Tam.Tam OShanter wrote:
> Hello All,
> Looking at implimenting an enterprise SAN that will host approximately 17
> applications (DB, Exchange etc...) and a LUN for storage of user data
> (profiles etc...).
> Approximately 40 TB or disk , effectively 20 due to a RAID 10 setup.
> Any caveats with this setup?
> The equipment is :
> EMC CX3.
> My main concern is that the disk real estate/LUN's dedicated to a given
> server (SQL Server for instance) will have its own disk spindles/heads.
> So if the Exchange Server is using the same SAN, but a different LUN, will
> they share disk heads?
> Your advice is warmly welocmed.
> Tam.
>
>
>
Hi
This group might not be the best place for your question and I think
you'll get a better reply if you contact the SAN vendor or post the
question in a SAN newsgroup. From your question it sounds like you are
missing some basic knowledge about how a SAN works...:-).
That being said, you will not share physical disks between different
LUNs in a SAN. Also you don't need to run all the disk on the same RAID
level, but you'd rather set the RAID level for each array based on the
usage of that array. For an array hosting an Exchange database, you'd
maybe set this up in RAID 5 because you need the space rather than the
better performance. For the SQL database and logfile, RAID10 is
generally a good choice but in some cases you could do with mdf's on
RAID 5 and ldf's on RAID10. That depends on the usage and load on your
server and only tests will show what's best for you.
--
Regards
Steen Schlüter Persson
Database Administrator / System Administrator|||you might want to have a look at this.
http://searchsqlserver.techtarget.com/tip/0,289483,sid87_gci1213487,00.html
I really don't think it is a good idea to hang write heavy applications like
Exchange and SQL off the same box.
--
Hilary Cotter
Director of Text Mining and Database Strategy
RelevantNOISE.Com - Dedicated to mining blogs for business intelligence.
This posting is my own and doesn't necessarily represent RelevantNoise's
positions, strategies or opinions.
Looking for a SQL Server replication book?
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"Tam OShanter" <tam@.oshanter.com> wrote in message
news:c5J4h.53895$i62.51034@.fe12.news.easynews.com...
> Hello All,
> Looking at implimenting an enterprise SAN that will host approximately 17
> applications (DB, Exchange etc...) and a LUN for storage of user data
> (profiles etc...).
> Approximately 40 TB or disk , effectively 20 due to a RAID 10 setup.
> Any caveats with this setup?
> The equipment is :
> EMC CX3.
> My main concern is that the disk real estate/LUN's dedicated to a given
> server (SQL Server for instance) will have its own disk spindles/heads.
> So if the Exchange Server is using the same SAN, but a different LUN, will
> they share disk heads?
> Your advice is warmly welocmed.
> Tam.
>
>
>|||I've built a cluster around the CX300 and its performance is terrible - the
internal scsi significantly out classed it.
The problem with the SAN's I've come into contact with is that they don't do
immediate writes very well, they are great at outstanding IO - the SQL
checkpoint process etc... but when it comes to writing to the transaction
log they fail miserably.
Writing the transaction log needs to be immediate, no outstanding IO is
allowed there so the SAN cannot handle the throughput.
Some background:
http://sqlblogcasts.com/blogs/tonyrogerson/archive/2006/09/22/1089.aspx
Always get one on trial and don't commit until you are absolutely sure it
will do what you want it to!
--
Tony Rogerson
SQL Server MVP
http://sqlblogcasts.com/blogs/tonyrogerson - technical commentary from a SQL
Server Consultant
http://sqlserverfaq.com - free video tutorials
"Tam OShanter" <tam@.oshanter.com> wrote in message
news:c5J4h.53895$i62.51034@.fe12.news.easynews.com...
> Hello All,
> Looking at implimenting an enterprise SAN that will host approximately 17
> applications (DB, Exchange etc...) and a LUN for storage of user data
> (profiles etc...).
> Approximately 40 TB or disk , effectively 20 due to a RAID 10 setup.
> Any caveats with this setup?
> The equipment is :
> EMC CX3.
> My main concern is that the disk real estate/LUN's dedicated to a given
> server (SQL Server for instance) will have its own disk spindles/heads.
> So if the Exchange Server is using the same SAN, but a different LUN, will
> they share disk heads?
> Your advice is warmly welocmed.
> Tam.
>
>
>|||SAN is not a product; it's a class of storage technologies. How does a SAN
perform is totally dependent on how that SAN is configured. Any broad stroke
statement on SAN performance is bound to be inaccurate in general (may be
valid in some particlar cases).
> So if the Exchange Server is using the same SAN, but a different LUN, will
> they share disk heads?
That depends on how you configure the LUNs. In most decent sized SANs, it is
common for LUNs to share spindles. Sharing spindles doesn't necessarily mean
unacceptable performance. It may perform less well than not sharing any
spindles, but the performance may still be within the expected level for your
particular app.
Linchi
"Tam OShanter" wrote:
> Hello All,
> Looking at implimenting an enterprise SAN that will host approximately 17
> applications (DB, Exchange etc...) and a LUN for storage of user data
> (profiles etc...).
> Approximately 40 TB or disk , effectively 20 due to a RAID 10 setup.
> Any caveats with this setup?
> The equipment is :
> EMC CX3.
> My main concern is that the disk real estate/LUN's dedicated to a given
> server (SQL Server for instance) will have its own disk spindles/heads.
> So if the Exchange Server is using the same SAN, but a different LUN, will
> they share disk heads?
> Your advice is warmly welocmed.
> Tam.
>
>
>