Comments on: When should you put data and logs on the same drive? http://www.brentozar.com/archive/2009/02/when-should-you-put-data-and-logs-on-the-same-drive/ Your technology pain-relief experts. Wed, 08 Feb 2012 16:37:59 +0000 hourly 1 http://wordpress.org/?v=3.3.1 By: David Eaton http://www.brentozar.com/archive/2009/02/when-should-you-put-data-and-logs-on-the-same-drive/comment-page-1/#comment-36609 David Eaton Fri, 20 Jan 2012 22:21:11 +0000 http://www.brentozar.com/?p=2542#comment-36609 A better configuration would be to group the RAID5 disks into to a pair of 8 Disk RAID5 LUNs and use the remaining 4 drives for another RAID10 LUN. This allows Logs and TempDB to be on thier own RAID10 arrays, and the data can be spread across the two RAID5 arrays. David A better configuration would be to group the RAID5 disks into to a pair of 8 Disk RAID5 LUNs and use the remaining 4 drives for another RAID10 LUN.

This allows Logs and TempDB to be on thier own RAID10 arrays, and the data can be spread across the two RAID5 arrays.

David

]]> By: Brent Ozar http://www.brentozar.com/archive/2009/02/when-should-you-put-data-and-logs-on-the-same-drive/comment-page-1/#comment-22735 Brent Ozar Wed, 18 Aug 2010 21:02:53 +0000 http://www.brentozar.com/?p=2542#comment-22735 Eric - my first suggestion would be to rebalance those disks out. Why stick with that existing setup? If you're starting from scratch, now's your chance to get it right, and 20 disks with RAID 5 is usually not the best configuration. Unfortunately I can't give you a fast & easy explanation on the numbers of disks - you'll want to use SQLIO to do testing on the array to find your bottlenecks. It might not be the RAID level at all. Eric – my first suggestion would be to rebalance those disks out. Why stick with that existing setup? If you’re starting from scratch, now’s your chance to get it right, and 20 disks with RAID 5 is usually not the best configuration.

Unfortunately I can’t give you a fast & easy explanation on the numbers of disks – you’ll want to use SQLIO to do testing on the array to find your bottlenecks. It might not be the RAID level at all.

]]> By: Eric http://www.brentozar.com/archive/2009/02/when-should-you-put-data-and-logs-on-the-same-drive/comment-page-1/#comment-22734 Eric Wed, 18 Aug 2010 21:00:24 +0000 http://www.brentozar.com/?p=2542#comment-22734 Brent, I've got a SAN with 4 disks setup with raid 10 and then 20 disks setup with RAID 5. Which would be the better choice for housing logs and the temp database? I'm assuming the RAID 5 disks will be faster because of the number of them. If that is the case, roughly how many disks would have to be added to the RAID 10 setup to get up to speed with the RAID 5 array? Thanks for your input. Eric Brent,

I’ve got a SAN with 4 disks setup with raid 10 and then 20 disks setup with RAID 5. Which would be the better choice for housing logs and the temp database? I’m assuming the RAID 5 disks will be faster because of the number of them. If that is the case, roughly how many disks would have to be added to the RAID 10 setup to get up to speed with the RAID 5 array? Thanks for your input.

Eric

]]> By: Brent Ozar http://www.brentozar.com/archive/2009/02/when-should-you-put-data-and-logs-on-the-same-drive/comment-page-1/#comment-21513 Brent Ozar Fri, 04 Jun 2010 11:55:31 +0000 http://www.brentozar.com/?p=2542#comment-21513 Zinto - thanks for your comments. Unfortunately, the SQLCruise training is only available to people who attend the cruise. We have to charge money to cover our expenses, and if I gave that training away for free on the blog, then nobody would attend the cruise. About the virtual data & log files, those are all good questions, and the answer is always, "It depends." There's a ton of variables - the type of SAN, direct attached storage, other servers sharing the same spindles, the HBA load balancing mechanism, and so forth. That's beyond what I can cover quickly in the blog, unfortunately. Zinto – thanks for your comments.

Unfortunately, the SQLCruise training is only available to people who attend the cruise. We have to charge money to cover our expenses, and if I gave that training away for free on the blog, then nobody would attend the cruise.

About the virtual data & log files, those are all good questions, and the answer is always, “It depends.” There’s a ton of variables – the type of SAN, direct attached storage, other servers sharing the same spindles, the HBA load balancing mechanism, and so forth. That’s beyond what I can cover quickly in the blog, unfortunately.

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