That's interesting. Almost everyone else I know that's run the numbers has
shown a considerably higher cost per mb for SAN over DAS, and have had to
use the "soft" cost justifications to get them back in line.

Granted, you were buying 5-20 times the required storage per machine, we
usually shoot for 2-3 times. 

For grins, what's the total capacity of your SAN, and what's the current
utilization at?
------------------------------------------------------
Roger D. Seielstad - MCSE
Sr. Systems Administrator
Inovis - Formerly Harbinger and Extricity
Atlanta, GA


> -----Original Message-----
> From: Wes Owen [mailto:[EMAIL PROTECTED]] 
> Sent: Friday, October 04, 2002 2:00 PM
> To: NT 2000 Discussions
> Subject: RE: Basic SAN question
> 
> 
> Disagree.  We are moving all of our servers to the SAN, 
> including booting
> the OS from the SAN.  We were able to show a break even 
> scenario in hard
> costs, and then the "soft cost" were able to push things over the top.
> 
> Largely because of our purchasing habits, I admit.  We would 
> buy servers
> with 100 to 400 GB's of drive space because they (developers 
> and DBA's, not
> me!) might need it within the three year lease cycle.  Then 
> when it came off
> lease they may have used 15 or 20 GB's.  Also, booting from 
> SAN I lose the
> array card along with all the hard drives. 
> 
> Again just one man's opinion. 
> 
> -----Original Message-----
> From: Roger Seielstad [mailto:[EMAIL PROTECTED]] 
> Sent: Friday, October 04, 2002 11:15 AM
> To: NT 2000 Discussions
> Subject: RE: Basic SAN question
> 
> 
> IMO, the *right* answer is to not buy a SAN for generalized 
> storage. At the
> current price-per-mb rates of SAN solutions vs. Direct Attached
> Storage(DAS), I can waste a LOT of locally attached storage 
> before I break
> even moving to a SAN. 
> 
> Don't get me wrong - SAN's have their place. I just don't think most
> companies need them. And don't even get me started on NAS 
> boxes, either.
> 
> ------------------------------------------------------
> Roger D. Seielstad - MCSE
> Sr. Systems Administrator
> Inovis - Formerly Harbinger and Extricity
> Atlanta, GA
> 
> 
> > -----Original Message-----
> > From: Chris Levis [mailto:[EMAIL PROTECTED]]
> > Sent: Friday, October 04, 2002 11:27 AM
> > To: NT 2000 Discussions
> > Subject: RE: Basic SAN question
> > 
> > 
> > Thanks for the warning.
> > 
> > I do plan on minimizing the number of LUNs, but my boss asked
> > the question
> > and I wanted to be sure to have the /right/ answer instead of the
> > /right-now/ answer.
> > 
> > > -----Original Message-----
> > > From: Roger Seielstad [mailto:[EMAIL PROTECTED]]
> > > Sent: Friday, October 04, 2002 7:51 AM
> > > To: NT 2000 Discussions
> > > Subject: RE: Basic SAN question
> > > 
> > > 
> > > Chris,
> > > 
> > > Most vendors will allow you to slice and dice a SAN array
> > > into as many LUNs of whatever size you want. Its absolutely 
> > > the wrong thing to do, but it certainly can be done.
> > > 
> > > Any time a phisical platter is partitioned, you're going to
> > > take a performance hit - simply put, the heads can't be in 
> > > two places at once, so if two systems are trying to access 
> > > data which is physically on the same platter, but logically 
> > > on different LUNs, there is head contention, and one of the 
> > > two must wait for the other to finish "using" the heads, and 
> > > then pay the additional price of a head seek across the 
> > > platter to its assigned set of cylinders.
> > > 
> > > In the case of your single 500GB RAID5 set in your SAN being
> > > split into 300/100/50/50, you have in reality created 4 
> > > partitions on each spindle, with 60%/20%/10%/10% split on 
> > > each spindle. With a large number of platters, and larger 
> > > stripe sizes, its theoretically possible to reduce the 
> > > chances of contention within the SAN, but realistically 
> > > speaking, chances are there is going to be some contention, 
> > > and therefore some performance hits associated with managing 
> > > your disks this way.
> > > 
> > > Its one of the lies^H^H^H^H omissions commonly done in the
> > > sales pitches of the big storage vendors.
> > > 
> > > ------------------------------------------------------
> > > Roger D. Seielstad - MCSE
> > > Sr. Systems Administrator
> > > Inovis - Formerly Harbinger and Extricity
> > > Atlanta, GA
> > > 
> > > 
> > > > -----Original Message-----
> > > > From: Chris Levis [mailto:[EMAIL PROTECTED]]
> > > > Sent: Thursday, October 03, 2002 2:07 PM
> > > > To: NT 2000 Discussions
> > > > Subject: Basic SAN question
> > > > 
> > > > 
> > > > If you have a RAID-5 array of (let's say) 500GB, can you create 
> > > > LUNs of an arbitrary size to be presented to the 
> servers?  E.g, a 
> > > > 300GB, a 100GB, and
> > > > two 50GB?   Or is there a convention that all LUNs have to be 
> > > > a uniform
> > > > size?
> > > > 
> > > > Thanks!
> > > > 
> > > > 
> > > > 
> > > > 
> > > > 
> > > > ___________________________
> > > > Chris Levis
> > > > Applied Geographics, Inc.
> > > > 
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