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Fast VP in VVOLs
Hello,
I'm confused about Fast VP mechanism in VVOLs.
for example, we have a 3 pool.
1- 1st pool contain SAS Flash disks and SAS Disk
2- 2nd pool contain NL-SAS Disks
3- 3rd pool contain SAS and NL-SAS Disks
I create a VVOL datastore and have 30% capacity of 1st pool, 20% capacity of 2nd pool and 50% capacity pf 3rd pool. so 3 capability profile assigned to this VVOL.
I have a storage policy with name "Extreme" in vmware that contain Drive Type: ExtremePerformaceTier.
When a VM is created under Extreme Storage policy, what would happen and where it will be stored?
How Fast VP mechanism act and relocating VM, if selected datastore is not proper?
Regards,
Mohammad
AndreD Dell
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July 15th, 2017 04:00
Hi Mohammad,
Apologies for the delay.
So yes, everything is based on the storage policy you chose.
The system will never know if the admin made a mistake. How could it?
If this was an example with normal LUNs, and you had 3 separate pools without any relation between them (one Flash, one SAS, and one NL-SAS), if your admin creates a VM in the wrong datastore, there is no way the system will correct this either. Neither VMware or the Unity array can ever know that a mistake was made.
If this was a single pool with 3 tiers however, FAST VP would still kick in and move the hot data up to faster drives if needed (assuming all LUNs were set to relocation policy autotier). But as discussed FAST VP doesn't work in your case (doesn't work across pools, nor does it work across storage policies).
So again, whatever storage policy is chosen, that is what is applied. And that will then map back to whatever drives match that policy.
Andre @ Dell EMC
AndreD Dell
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July 3rd, 2017 05:00
Hi Mohammad,
FAST VP only works within the same pool, not across pools.
You setup seems over complicated to me.
Check out the vVols White Papper here:
https://support.emc.com/docu69894_Unity_Family_Configuring_Vvols.pdf?language=en_US
Andre @ Dell EMC
msamadzadegan
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July 3rd, 2017 20:00
Hi Andre,
Thanks but i read FAST Technology and Virtualization Integration Documents and those are not explain so well.
Yes your right, Fast VP works within the pool. But consider my example. when you have 3 pool with different drive types, some black boxes are exist.
1- In VM creation time, I select a Storage Policy that contain Extreme Performance Drive type, so my VVOL is compatible. VVOL has enough free space but I don't know this free space is in Extreme Performance drivers or not!!! , So if the Flash drives is not free, how would be managed my request and where would be create my VM?, Logically new VM can not create on flash drives so my storage policy has wrong action.
2- If an expert create a VM and select wrong Storage Policy, how the system detect it and fixed it?. for example, On my VVOL that i explain before, VVOL is compatible with Database, Archive and Normal Operation. During VM creation, I Select Archive Storage Policy by mistake for Database VM. So VM would be located in Pool with NL-SAS Drives probably. How system detect this VM has more activity and IOPS than Archival VM and How notify me about this?
Regards,
Mohammad
msamadzadegan
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July 7th, 2017 19:00
Hi,
Can anyone answer this question?
msamadzadegan
15 Posts
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July 28th, 2017 21:00
Thanks Andre,
So SPBM just useful when many LUN exist and we don't know what drive is behind the LUN.