tag:blogger.com,1999:blog-1841626496323335774.post1959372325502887217..comments2023-05-30T08:51:36.400-04:00Comments on AaronDelp.com: It's Now All About the IOPs!Aaron Delphttp://www.blogger.com/profile/04330656671495950454noreply@blogger.comBlogger13125tag:blogger.com,1999:blog-1841626496323335774.post-22589432598368040542014-04-29T20:59:05.689-04:002014-04-29T20:59:05.689-04:00I added my definition of IOPs as well as a link to...I added my definition of IOPs as well as a link to the Wikipedia article for clarification.Aaron Delphttps://www.blogger.com/profile/04330656671495950454noreply@blogger.comtag:blogger.com,1999:blog-1841626496323335774.post-4944741951129735032014-04-24T14:52:46.497-04:002014-04-24T14:52:46.497-04:00What is an IOP?
Input/Output Per..... Input/Outpu...What is an IOP?<br /><br />Input/Output Per..... Input/Output/Processor? <br /><br />From the context it's pretty clear you meant IOPS, but five years after writing, the typo still confuses.<br /><br />Half a decade and continued linkage essentially turns your blog post into journalism. Journalism requires quite definition of otherwise obvious acronyms, so as to retain the reader and answer Unknownhttps://www.blogger.com/profile/17079963795689227974noreply@blogger.comtag:blogger.com,1999:blog-1841626496323335774.post-29742723244611406962013-09-12T08:22:08.659-04:002013-09-12T08:22:08.659-04:00As you pointed out, there will always be something...As you pointed out, there will always be something that limits performance on an individual device or on a network. No mater how many improvements are made, there will always be something that takes priority because of need.<br /><br />When one thing is enhanced, then the shortfalls in another part of the system become more obvious. It may also be that at times the level of innovation related to Computer memory and performancehttp://greenmangaming.bluepromocode.com/greenmangaming-promo-code/noreply@blogger.comtag:blogger.com,1999:blog-1841626496323335774.post-71358725161538607342010-08-04T16:08:00.911-04:002010-08-04T16:08:00.911-04:00Thanks for the comment Andrew! I admit I don'...Thanks for the comment Andrew! I admit I don't have a source I can point you to other than "experience". By that I mean I have run across those numbers from many different manufacturers (NetApp and EMC for instance) but I would have a hard time digging up a source because I have been throwing them around for some time now.Aaron Delphttps://www.blogger.com/profile/04330656671495950454noreply@blogger.comtag:blogger.com,1999:blog-1841626496323335774.post-50069762928735675052010-08-04T11:57:34.441-04:002010-08-04T11:57:34.441-04:0080 (SATA), 120 (10K SCSI), 180 (15K SCSI) IOPS are...80 (SATA), 120 (10K SCSI), 180 (15K SCSI) IOPS are pretty commonly used/safe examples.Andrew Storrshttps://www.blogger.com/profile/18056687667967806573noreply@blogger.comtag:blogger.com,1999:blog-1841626496323335774.post-59615968119461331852010-07-29T12:53:27.677-04:002010-07-29T12:53:27.677-04:00curious arrpn where did you get you 75 from in the...curious arrpn where did you get you 75 from in the example ?Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-1841626496323335774.post-43452829326138494002009-11-20T18:56:12.878-05:002009-11-20T18:56:12.878-05:00With the latest Seagate SAS drives and WD Sata dri...With the latest Seagate SAS drives and WD Sata drives having random read/write numbers not that far apart what would the driving points be towards staying with the far more ( double ? ) expensive drives.<br /><br />Karan,<br /> I don't think recent testing backs those numbers up. You're overspecing FC and underselling the SATA [look at WD Raptor drives which are within 20% of Seagates Unknownhttps://www.blogger.com/profile/05907439265693612750noreply@blogger.comtag:blogger.com,1999:blog-1841626496323335774.post-82928405763643521732009-10-09T22:03:41.044-04:002009-10-09T22:03:41.044-04:00Andrew - Thank you for your comment!Andrew - Thank you for your comment!Aaron Delphttps://www.blogger.com/profile/04330656671495950454noreply@blogger.comtag:blogger.com,1999:blog-1841626496323335774.post-16979502708522876522009-10-09T15:36:07.433-04:002009-10-09T15:36:07.433-04:00Your numbers are correct Aaron. For RAID5 the writ...Your numbers are correct Aaron. For RAID5 the write calculation is N*IOPS/4. RAID6 is harder to calculate as the algorithm used can vary greatly from one vendor/controller to the next, but the write penalty should be somewhere between 3-20% greater than RAID5. <br /><br />In your example of 4xSATA disks if it was RAID5 (I've seen this many times before in SMBs) the write performance would beAndrew Storrshttps://www.blogger.com/profile/18056687667967806573noreply@blogger.comtag:blogger.com,1999:blog-1841626496323335774.post-15300345670662094192009-10-08T10:07:38.905-04:002009-10-08T10:07:38.905-04:00Karan - Thank you, that is great information!
Tom...Karan - Thank you, that is great information!<br /><br />Tom - I'm not an expert here by any stretch. I could be completely wrong so don't take this as fact. This is what I'm seeing and I'm over simplifying the calculations. As I understand for RAID-1, read performance and write performance are calculated differently. For read performance, IOPs are calculated as N*IOPS where NAaron Delphttps://www.blogger.com/profile/04330656671495950454noreply@blogger.comtag:blogger.com,1999:blog-1841626496323335774.post-40488855323301217912009-10-08T10:04:26.663-04:002009-10-08T10:04:26.663-04:00Hi Aaron, I came up with the same conclusions, for...Hi Aaron, I came up with the same conclusions, for the next couple or 3 years, the bottleneck will be at the storage level... Then the SSD disks will take over. They are already up to 30x faster than a regular spindle... If you're looking at simple formulas to calculate IOPS read these blog posts: http://deinoscloud.wordpress.com/2009/09/11/understanding-disk-iops/<br /> and<br />http://PiroNethttp://deinoscloud.wordpress.comnoreply@blogger.comtag:blogger.com,1999:blog-1841626496323335774.post-42134201017239310872009-10-08T09:53:00.797-04:002009-10-08T09:53:00.797-04:00You are right on!! Always size a SAN for Performan...You are right on!! Always size a SAN for Performance and not space. <br /><br />It is also good to know that IOPS are directly tied to latency.<br /><br />Eg. SATA 40 to 60 IOPS < 20ms<br />Vs<br />FC 15K drive of 200to 300 IOPS < 20ms<br /><br />Casue one can say 100 IOPS but it might be at latency to 100ms.Karan Bhagathttp://twitter.com/kbhagatnoreply@blogger.comtag:blogger.com,1999:blog-1841626496323335774.post-24765222345411817312009-10-08T09:40:07.200-04:002009-10-08T09:40:07.200-04:00Using the approximate SAS disk IOPs numbers you po...Using the approximate SAS disk IOPs numbers you posted, how is it possible to approximate the number of VMs I can have on a SAN with 6 300GB SAS disks in RAID 1??<br /><br />Thank you, TomAnonymousnoreply@blogger.com