Fwd: FW: Informix on IBM SAN?

Doug: I have been using an IBM-2105/E20 for our production database for about ten months now all configured RAID5. Our array has 3Gig read cache and 192Meg of write cache NVS per cluster. The system is incredibly fast, but you can significantly improve performance by experimenting and laying out your data. Regardless of what the IBM sales reps say, 192 MEG of NVS does become a bottleneck at times. Lay out your data to help destaging. During testing I have found a few things which DO or SHOULD improve throughput. - Distribute you load across DA pairs, don't overload a DA pair. - Distribute you load across loops A and B per DA . - Distribute you load between clusters . The base frame has two drawers of disks per DA pair/loop. Balance the load between the clusters. . IN my OPINION be skeptical of adding the expansion frame adding more drawers per loop. - Create your logical devices small enough to allow creation of logicals on you host system to span DA pairs. Especially if using SCSI attached devices! This will allow you to in effect get a bigger pipe to you data. - When setting up your failover, balance your primary LUNS across both the primary and alternate paths. - MAKE SURE YOU HAVE THE LATEST MICRO CODE!!!!!!!!!!!!! Be AWARE that I have experinced four total array outages over the last ten months. The micro code seems to have stabelized now and the only issues are some strange SCSI errors plaguing one of our HP N4000's. Also note the outages ONLY occurred as a result of configuration changes. NO, I did nothing wrong during the configurations... regards jim namenek >From: "Namenek, James H." <namenej@diebold.com> >To: namenej@hotmail.com >Subject: FW: Informix on IBM SAN? >Date: Tue, 3 Oct 2000 11:06:05 -0400 > >-----Original Message----- >From: Namenek, James H. >Sent: Tuesday, October 03, 2000 11:04 AM >To: Namenek, James H. >Subject: FW: Informix on IBM SAN? > > >forward... > >regards >Jim Namenek > >phone: 330-490-5929 >fax: 330-490-5735 >email: namenej@diebold.com > > > >-----Original Message----- >From: d_weber@telocity.com [mailto:d_weber@telocity.com] >Sent: Monday, October 02, 2000 11:35 PM >To: informix-list@iiug.org >Subject: Informix on IBM SAN? > > >Hello! > >Does anyone have experience running Informix (or any database, for >that matter) on the new IBM SAN (storage area network) equipment? My >company is proposing that we move our Informix database tables to SAN, >and I've got some concerns. > >Seeing as these new devices abstract the disks into logical volumes, >and are RAID underneath, how do you deal with issues such as table >fragmentation, placement on disk (i.e. inner tracks, center tracks) >etc? You won't know which disk the tables are on. Or, are these new >disk systems just so fast, and so sweet, that I no longer have to >think (worry) about such things? That's what the hardware guys are >telling me, but it sounds too good to be true. > >Thanks in advance. >Doug _________________________________________________________________________ Get Your Private, Free E-mail from MSN Hotmail at http://www.hotmail.com. Share information about yourself, create your own public profile at http://profiles.msn.com.