>the ISP feature of VM would allow you to drill down to individual spindles and >place subdisks on each spindle.
Individual spindles of the RAID group? Doesn't that defeat the purpose of the RAID group? Striping across LUNs gets ...interesting; we usually just use them concat. Of course that's with a real SAN array such as Hitachi 99x0 or Sun 61x0. I'm not sure I see the point of striping LUNs. If you are having performance problems from the array, fix the layout of the RAID group on the array: that's why you pay the big bucks to Hitachi for their hardware. I not sure I want to know about the load that could flatline a RAID-6 array of 6 15K RPM Fiber channel disks backed by a multigigabyte RAM cache. I have certainly seen bad storage layout on the host cause hot spots. That's when people make ridiculous numbers of small (gigabyte or so) volumes scattered all over the place -- another argument against the old way of doing things with databases and raw volumes (if you're going to use raw volumes at least use decent size ones not 2GB each ). While old (< 10) Solaris AIO did indeed suck dead bunnies thorugh a straw for performance, that's no longer a problem in Solaris 10 ZFS if you use it natively (using "branded" zones to run Solaris 8 and 9 puts the old AIO interface in front) nor would I expect it to be a problem with VxFS. ________________________________ From: veritas-vx-boun...@mailman.eng.auburn.edu [mailto:veritas-vx-boun...@mailman.eng.auburn.edu] On Behalf Of William Havey Sent: Wednesday, January 06, 2010 12:00 PM To: przemol...@poczta.fm Cc: veritas-vx@mailman.eng.auburn.edu Subject: Re: [Veritas-vx] Relayout volume from 2 to 4 columns VM views the two raid groups as single LUNs. It needn't be concerned with the layout of each raid group. To change from 2 columns to 4 columns use the relayout option to vxassist and also specify the two new LUNs on which to place the two new columns. That being said, the ISP feature of VM would allow you to drill down to individual spindles and place subdisks on each spindle. Bill On Wed, Jan 6, 2010 at 6:36 AM, <przemol...@poczta.fm<mailto:przemol...@poczta.fm>> wrote: Hello, we are using VSF 5.0 MP3 on Solaris 10 attached to SAN-based hardware array. On this array we have created 2 raid groups and on each RG we have created a few LUNs: raid group: RG1 RG2 LUN1 LUN7 LUN2 LUN8 LUN3 LUN9 LUN4 LUN10 LUN5 LUN11 LUN6 LUN12 For performance reason some of our volumes are striped between the two raid groups (using two columns ncol=2) e.g.: pl <name> <vol> ENABLED ACTIVE 419256320 STRIPE 2/128 RW In this configuration IOs involves two raid groups. It seems that in the future in certain cases performance might be not as expected so we would like to add two additional LUNs (taken from two additional raid groups) and relayout the whole volume from 2-col to 4-cols e.g.: raid group: RG1 RG2 RG3 RG4 LUN1 LUN7 LUN13 LUN19 LUN2 LUN8 LUN14 LUN20 LUN3 LUN9 LUN15 LUN21 LUN4 LUN10 LUN16 LUN22 LUN5 LUN11 LUN17 LUN23 LUN6 LUN12 LUN18 LUN24 Is it possible to order relayout of existings volumes to spread it over all four RGs ? Can I point somehow that it should relayout using these particular LUNs ? Regards Przemyslaw Bak (przemol) -- http://przemol.blogspot.com/ ---------------------------------------------------------------------- Milosc, praca, pieniadze. Sprawdz swoj horoskop na dzis >> http://link.interia.pl/f2531 _______________________________________________ Veritas-vx maillist - Veritas-vx@mailman.eng.auburn.edu<mailto:Veritas-vx@mailman.eng.auburn.edu> http://mailman.eng.auburn.edu/mailman/listinfo/veritas-vx
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