Comments on: XiV Part II http://www.thestoragearchitect.com/2008/01/07/xiv-part-ii/ Storage and Virtualisation Tue, 07 Sep 2010 19:15:05 +0100 http://wordpress.org/?v=2.8.6 hourly 1 By: Chris M Evans http://www.thestoragearchitect.com/2008/01/07/xiv-part-ii/comment-page-1/#comment-230 Chris M Evans Thu, 10 Jan 2008 22:02:00 +0000 http://thestoragearchitect.wordpress.com/2008/01/07/xiv-part-ii/#comment-230 Ron, I think Nextra is generating more interest purely because of the involvement of Moshe Yanai in the company. Had he not been involved and the product come to market with storage "unkowns" then I'm sure it would have been a different case. Ron, I think Nextra is generating more interest purely because of the involvement of Moshe Yanai in the company. Had he not been involved and the product come to market with storage “unkowns” then I’m sure it would have been a different case.

]]> By: Ron Major http://www.thestoragearchitect.com/2008/01/07/xiv-part-ii/comment-page-1/#comment-229 Ron Major Thu, 10 Jan 2008 16:05:00 +0000 http://thestoragearchitect.wordpress.com/2008/01/07/xiv-part-ii/#comment-229 This is the same concept as the HP EVA. The EVA can level the IO performance by moving hot chunklets to less busy spindles. Chunklets are also spread to new disks when capacity is added to the array. Sparing is handled by reserving extra capacity equivalent to one or two drives across all of the disks. This eliminates idle spindles since all disks participate in the workload. RAID types are defined at the logical volume level rather than with disk groups.<br/><br/>It’s a great concept, but the EVA never became very popular. What is so remarkable about the XiV that has people so excited? This is the same concept as the HP EVA. The EVA can level the IO performance by moving hot chunklets to less busy spindles. Chunklets are also spread to new disks when capacity is added to the array. Sparing is handled by reserving extra capacity equivalent to one or two drives across all of the disks. This eliminates idle spindles since all disks participate in the workload. RAID types are defined at the logical volume level rather than with disk groups.

It’s a great concept, but the EVA never became very popular. What is so remarkable about the XiV that has people so excited?

]]> By: BarryWhyte http://www.thestoragearchitect.com/2008/01/07/xiv-part-ii/comment-page-1/#comment-228 BarryWhyte Wed, 09 Jan 2008 18:43:00 +0000 http://thestoragearchitect.wordpress.com/2008/01/07/xiv-part-ii/#comment-228 In answer to Carl's question, yes as new storage is added, the mirror sets will be intelligently re-ballanced. In answer to Carl’s question, yes as new storage is added, the mirror sets will be intelligently re-ballanced.

]]> By: Tony http://www.thestoragearchitect.com/2008/01/07/xiv-part-ii/comment-page-1/#comment-227 Tony Tue, 08 Jan 2008 20:08:00 +0000 http://thestoragearchitect.wordpress.com/2008/01/07/xiv-part-ii/#comment-227 Hi Chris, I try to give an answer here in this post:<br/>http://www.ibm.com/developerworks/<br/>blogs/page/InsideSystemStorage?entry=<br/>spreading_out_the_re_replication Hi Chris, I try to give an answer here in this post:
http://www.ibm.com/developerworks/
blogs/page/InsideSystemStorage?entry=
spreading_out_the_re_replication

]]> By: Carl http://www.thestoragearchitect.com/2008/01/07/xiv-part-ii/comment-page-1/#comment-226 Carl Tue, 08 Jan 2008 17:05:00 +0000 http://thestoragearchitect.wordpress.com/2008/01/07/xiv-part-ii/#comment-226 We also still the old problem of upgrade-balancing.<br/><br/>If you have X drives, but they're all full, do you have to add drives in a large batch to keep the write load spread out? It won't be very virtual if my data is grouped to physical devices by age.<br/><br/>Can this thing intelligently re-balance the data so that IO uses the whole virtual system? We also still the old problem of upgrade-balancing.

If you have X drives, but they’re all full, do you have to add drives in a large batch to keep the write load spread out? It won’t be very virtual if my data is grouped to physical devices by age.

Can this thing intelligently re-balance the data so that IO uses the whole virtual system?

]]> By: Chris M Evans http://www.thestoragearchitect.com/2008/01/07/xiv-part-ii/comment-page-1/#comment-225 Chris M Evans Tue, 08 Jan 2008 06:24:00 +0000 http://thestoragearchitect.wordpress.com/2008/01/07/xiv-part-ii/#comment-225 I guess it depends on whether it is a "thin" snapshot or not. If it is, then the creation is simple pointer copying, if not, then I suppose the whole array will be busy copying data. I wonder if there is a way to segment the distribution of blocks into zones to divide up the workload into tiers? I guess it depends on whether it is a “thin” snapshot or not. If it is, then the creation is simple pointer copying, if not, then I suppose the whole array will be busy copying data. I wonder if there is a way to segment the distribution of blocks into zones to divide up the workload into tiers?

]]> By: Mark http://www.thestoragearchitect.com/2008/01/07/xiv-part-ii/comment-page-1/#comment-224 Mark Mon, 07 Jan 2008 22:37:00 +0000 http://thestoragearchitect.wordpress.com/2008/01/07/xiv-part-ii/#comment-224 It gets even more interesting when you consider what happens when you take a snap of a virtual volume. It gets even more interesting when you consider what happens when you take a snap of a virtual volume.

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