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. > > > > > > ------ > > > You are subscribed as [EMAIL PROTECTED] > > > Archives: http://www.swynk.com/sitesearch/search.asp > > > To unsubscribe send a blank email to %%email.unsub%% > > > > > > > ------ > > You are subscribed as [EMAIL PROTECTED] > > Archives: http://www.swynk.com/sitesearch/search.asp > > To unsubscribe send a blank email to %%email.unsub%% > > > > ------ > You are subscribed as [EMAIL PROTECTED] > Archives: http://www.swynk.com/sitesearch/search.asp > To unsubscribe send a blank email to %%email.unsub%% > ------ You are subscribed as [email protected] Archives: http://www.swynk.com/sitesearch/search.asp To unsubscribe send a blank email to [EMAIL PROTECTED]
