<html xmlns:v="urn:schemas-microsoft-com:vml" xmlns:o="urn:schemas-microsoft-com:office:office" xmlns:w="urn:schemas-microsoft-com:office:word" xmlns:m="http://schemas.microsoft.com/office/2004/12/omml" xmlns="http://www.w3.org/TR/REC-html40"> <head> <meta http-equiv="Content-Type" content="text/html; charset=utf-8"> <meta name="Generator" content="Microsoft Word 15 (filtered medium)"> <style></style> </head> <body lang="EN-US" link="blue" vlink="purple"> <div class="WordSection1"> Looking at the first link he clearly states that ZIL is written to in a round robin fashion, I was under the impression that 2 log devices would then be faster than 1…unless mirrored of course.<o:p></o:p> <o:p> </o:p> If this is not true, what is the point of allowing more than 1 vdev as log device at all?<o:p></o:p> <o:p> </o:p> How can I test the max sped of my log device directly in OmniOS?<o:p></o:p> <o:p> </o:p> Br,<o:p></o:p> Rune<o:p></o:p> <o:p> </o:p> From: OmniOS-discuss [mailto:omnios-discuss-bounces@lists.omniti.com] On Behalf Of Nicholas George Sent: Wednesday, November 12, 2014 9:24 PM To: omnios-discuss@lists.omniti.com Subject: Re: [OmniOS-discuss] slog limits write speed more than it should<o:p></o:p> <o:p> </o:p> <div> From what I understand, ZFS writes to the intent log in a single threaded synchronous fashion. Adding three drives just means that the first block is written to the first drive synchronously, then the second block to the second drive synchronously, then the third to the third drive and then back around to the first. You don't actually increase your throughput beyond the performance of a single drive. <a href="http://nex7.blogspot.com/2013/04/zfs-intent-log.html">http://nex7.blogspot.com/2013/04/zfs-intent-log.html</a> <a href="http://www.nexentastor.org/boards/5/topics/6179">http://www.nexentastor.org/boards/5/topics/6179</a><o:p></o:p> </div> <div> <o:p> </o:p> <div> On Wed, Nov 12, 2014 at 6:21 PM, Rune Tipsmark <<a href="mailto:rt@steait.net" target="_blank">rt@steait.net</a>> wrote:<o:p></o:p> <blockquote style="border:none;border-left:solid #CCCCCC 1.0pt;padding:0in 0in 0in 6.0pt;margin-left:4.8pt;margin-right:0in"> <a href="http://www.fusionio.com/products/iodrive" target="_blank">http://www.fusionio.com/products/iodrive</a> 160GB SLC<o:p></o:p> <div> <div> -----Original Message----- From: Bob Friesenhahn [mailto:<a href="mailto:bfriesen@simple.dallas.tx.us">bfriesen@simple.dallas.tx.us</a>] Sent: Wednesday, November 12, 2014 3:17 PM To: Rune Tipsmark Cc: <a href="mailto:omnios-discuss@lists.omniti.com">omnios-discuss@lists.omniti.com</a> Subject: Re: [OmniOS-discuss] slog limits write speed more than it should On Wed, 12 Nov 2014, Rune Tipsmark wrote: > > each SLOG device can easily handle much more than 6000 IOPS Where may we find the specifications for the SSDs you are using? 6000 IOPS sounds like it might be quite a lot, depending on the SSD used. Bob -- Bob Friesenhahn <a href="mailto:bfriesen@simple.dallas.tx.us">bfriesen@simple.dallas.tx.us</a>, <a href="http://www.simplesystems.org/users/bfriesen/" target="_blank"> http://www.simplesystems.org/users/bfriesen/</a> GraphicsMagick Maintainer, <a href="http://www.GraphicsMagick.org/" target="_blank"> http://www.GraphicsMagick.org/</a> _______________________________________________ OmniOS-discuss mailing list <a href="mailto:OmniOS-discuss@lists.omniti.com">OmniOS-discuss@lists.omniti.com</a> <a href="http://lists.omniti.com/mailman/listinfo/omnios-discuss" target="_blank">http://lists.omniti.com/mailman/listinfo/omnios-discuss</a><o:p></o:p> </div> </div> </blockquote> </div> <o:p> </o:p> </div> </div> </body> </html>