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VNX Write Intent Log Disk Amount
Hello,
I have got a question concerning VNX Write Intent Log (WIL) performance.
I know that WIL on pool LUNS is not supported and WIL on VAULT drives not recommended.
The machines are two VNX using MirrorView/S.
How much SAS disks do I have to put in a RAID group to have enough disk performance for WIL. Is a RAID-1 with 2 SAS 10K disks enough? Are there rules of thumb or a calculator for this issue?
regards
Robert
isn't there a typo in that KB?
The WIL is stored on a pair of 2 GB LUNs (one for each SP) at current levels of VNX OE, although with older levels of flare, these can be as small as 128MB. These can either be RAID-group based LUNs, metaLUNs or Thick Pool LUNs. The same applies to CPL (Clone Private LUNs).
Virtual Provisioning LUNs are not supported for the WIL
What about disk performance for WIL? What kind of RAID group configuration is needed for WIL?
Is RAID 1+1 R1 enough or do I need 4+1 R5 or 8+1 R5 or 4+4 R1/0 ? I do not want to use more disks for that RG as necessary, because RG will only be used for WIL not for other LUNs. So less is more :-)
regards
Robert
I am getting reading to configure MirrorView for a brand new set of VNX. At each site i have 4 x 300g 15k drives that will be configured into 2+2 R1/0 RG. Probably an overkill but i am not sure what to expect from WIL I/O numbers, this should suffice.
sameek
60 Posts
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Posted January 30th, 2015 04:00
Hi
Please check Kb article given below this may help you
https://emc--c.na5.visual.force.com/apex/KB_BreakFix_1?id=kA1700000000MdD
Thanks
sameeksha