Most databases are just like Exchange. Microsoft SQL surely is, and I would presume Oracle is too. DB access is random (except for transaction logs, which are sequential writes).
For Fujitsu FC drives: http://discountechnology.com/Fujitsu-MAX3147FC-Fiber-Fibre-Channel-Hard-Driv e#specs go down to the section on "specifications". Note the sequential values for read/write vs. the average vs. the full track. The "fully random" or "database IOPS" for those drives is 1000 ms / (8.5 ms + 2 ms) = 95 IOPS. The numbers you were quoted were for average access. That is: 1000 ms / ( ((3.3 ms + 3.8 ms) / 2) + 2 ms) = 180 IOPS. Regards, Michael B. Smith, MCITP:SA,EMA/MCSE/Exchange MVP My blog: http://TheEssentialExchange.com/blogs/michael Link with me at: http://www.linkedin.com/in/theessentialexchange From: Joe Fox [mailto:[EMAIL PROTECTED] Sent: Tuesday, September 23, 2008 11:30 AM To: MS-Exchange Admin Issues Subject: Re: SAN Setup Recommendations That I don't know. I believe they are Fujitsu Fibre Channel drives (10K and 15K) for our Clariion CX3-10. Not sure on the OEM of the SATA drives for the same. For my application it's a SAN being used for Oracle, but I'll double check those numbers. Come to think of it, it was a lunch meeting with the engineer and our sales guy, so he could have been exaggerating some. :) Thanks for the explanation. Joe Fox Systems/Network Administrator Mobile# (716) 846-9308 http://www.linkedin.com/in/josephfoxjr On Tue, Sep 23, 2008 at 11:19 AM, Michael B. Smith <[EMAIL PROTECTED]> wrote: Is that sequential read only? 'Cuz those numbers seem high. Very high. What are the physical drive types and models? If you can't get those, the relevant metrics are: 1] inter-track latency, 2] full-bore average read access, and 3] full-bore average write access. For Exchange 2007 database access, which is completely random, per 10 K RPM spindle you generally see something like 1] 1 ms, 2] 8 ms, and 3] 12 ms. On average, read:write is 1:1, so you average 8 + 12 = 20 / 2 = 10 ms average access. This gives you an IOPS of 1000 ms / (10 ms + 1 ms) = 91 IOPS Big difference in performance and capacity planning between 91 IOPS and 120 IOPS. I covered this recently in: http://theessentialexchange.com/blogs/michael/archive/2008/09/19/it-s-all-ab out-the-iops-silly.aspx and http://peach.ease.lsoft.com/scripts/wa.exe?A2=ind0809 <http://peach.ease.lsoft.com/scripts/wa.exe?A2=ind0809&L=EMO-NEWSLETTER&T=0&; F=&S=&P=1470> &L=EMO-NEWSLETTER&T=0&F=&S=&P=1470 Note that 100% sequential read eliminates the inter-track latency, and the same drive gives you an IOPS of 125, much closer to the numbers you were told. You need to verify that you are being told what you THINK you are being told. Salespeople tend to quote the most favorable number. Regards, Michael B. Smith, MCITP:SA,EMA/MCSE/Exchange MVP My blog: http://TheEssentialExchange.com/blogs/michael Link with me at: http://www.linkedin.com/in/theessentialexchange From: Joe Fox [mailto:[EMAIL PROTECTED] Sent: Tuesday, September 23, 2008 11:02 AM To: MS-Exchange Admin Issues Subject: Re: SAN Setup Recommendations I just met with my EMC Rep last week as we need to add my disk to our SAN. Here are the figures that he gave me on IOPS: 15K RPM - 180 IOPS (FC Drives) 10K RPM - 120 IOPS (FC Drives) 7.2K RPM - 70-80 IOPS (SATA Drives) HTH. Joe Fox Systems/Network Administrator Mobile# (716) 846-9308 http://www.linkedin.com/in/josephfoxjr On Wed, Sep 17, 2008 at 1:52 PM, Sean Martin <[EMAIL PROTECTED]> wrote: I'm not at all experienced on Exch 2007, but if the same disk recommendations for Exch 2003 still hold true, I have the following advice: 1) Migrate one of your transaction log LUNs to a separate, dedicated RAID 1 group. You want to have your logs on separate spindles if at all possible. I'm not familiar with HP's SAN offering, but you should be able to migate the LUN and have it be transparent to the host. (Since you mentioned having 2 VRAID1 on the second disk group, I'm assuming the host see's these as two different physical disks.) 2) Typically RAID 10 is recommended for hosting info stores, but depending on your user load (read: IOPS), RAID 5 may suit your needs just fine. However, given the number of DBs you're supporting (and not knowing the number/type of users) I would be inclined to recommend at least two RAID5 groups (on dedicated spindles) for hosting each of your storage groups. 3) It may be too late, but I believe it is recommended to build separate storage groups before populating each storage group with multiple databases: Your Setup: SG1 - DB1, DB2, DB3, DB4 SG2 - DB5, DB6, DB7, DB8 Recommended: SG1 - DB1, DB5 SG2 - DB2, DB6 SG3 - DB3, DB7 SG4 - DB4, DB8 The obvious disadvantage is you would want to provide 4 separate RAID 1 groups for logs. - Sean On Wed, Sep 17, 2008 at 9:15 AM, Jeremy Phillips <[EMAIL PROTECTED]> wrote: How many disks are in each disk group? Thanks, Jeremy Phillips -----Original Message----- From: Travis Krampy [mailto:[EMAIL PROTECTED] Sent: Wednesday, September 17, 2008 10:12 AM To: MS-Exchange Admin Issues Subject: Re: SAN Setup Recommendations There are 2 disk groups actually, one that is a RAID5 and one that is a RAID1 The raid 5 disk group is split into 8 VRAID5 sets and the RAID1 disk group is split into 2 VRAID1 sets. Sorry I was not clear on this. Plus this is inherited, i never set this up, thats why im asking the experts! Travis "Barsodi.John" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] Sounds like you have one disk group and you've created several LUNs with varying Vraid types(1,5) within that Disk Group. Just remember the Vraid1 and Vraid5 sets are sharing the same disks within that Disk Group. Log writing and DB writing have different write patterns(sequential vs. random) so placing them on the same set of spindles could cause head contention. Best practice is separate spindles for logs and DB. Sounds like resources are limited, and depending on your performance requirements, this could be fine. - John Barsodi -----Original Message----- From: Travis Krampy [mailto:[EMAIL PROTECTED] Sent: Wednesday, September 17, 2008 9:50 AM To: MS-Exchange Admin Issues Subject: Re: SAN Setup Recommendations I think, from how I am looking at it, it seems that all disks on the are all together in one big array (RAID5) then broken down into several smaller VRAID5 arrays. It looks like there is about 2TB of disk space allocated to Exchange each are 72Gb 10k drives Does that help any? Thanks Travis "Martin Blackstone" <[EMAIL PROTECTED]> wrote in message news:[EMAIL PROTECTED] > I'm not sure I understand it either. > Are these luns on separate spindles or all the same ones? How many disks > are > there dedicated to Exchange? > > -----Original Message----- > From: Jeremy Phillips [mailto:[EMAIL PROTECTED] > Sent: Wednesday, September 17, 2008 9:01 AM > To: MS-Exchange Admin Issues > Subject: RE: SAN Setup Recommendations > > Sounds right at first glance (I'm not sure I understand *exactly* how the > SAN is configured) but my main question would be whether the drives can > support the iops needed? > > Thanks, > > Jeremy Phillips > > -----Original Message----- > From: Travis Krampy [mailto:[EMAIL PROTECTED] > Sent: Wednesday, September 17, 2008 8:28 AM > To: MS-Exchange Admin Issues > Subject: SAN Setup Recommendations > > Hi All, > > Forgive me if I am not explaining this correctly... > > I am currently working in implementing an Exchange 2007 CAS/HT server as > well as an exchange 2007 server as a secondary mailbox server with the > existing Exchange 2003 seerver. > > Currently the Exchange 2003 server is setup to have all Logs and DB's on a > SAN. > > Before I set up the new exchange 2007 back end server, i want to make sure > that the SAN is setup properly for Exchange. > > As of now, there are 2 storage groups with 4 stores in each storage group. > > On the SAN, each store is stored in 8 individual Luns that are VRAID 5 > > the logs are stored seperately for each storage group in their own LUN > that > is a VRAID 1 > > so on my exchange server, i have 8 drives that are for stores, and drives > for logs. > > Does this sound like the SAN is implemented correctly for Exchange? > > Please advise > > Thanks > > Travis ~ Ninja Email Security with Cloudmark Spam Engine Gets Image Spam ~ ~ http://www.sunbeltsoftware.com/Ninja ~
