compdigit44
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ESXi 5.1 Windows 2008 Failover Cluster
I have two Windows 2008 R2 VM's setup with RDM's in a Failover cluster. When I present the Lun to the VM I set the PSP to MRU. I noticed when I go to Storage -> Devices some Lun are showing RR while other are MRU.
I have also noticed when I click on some LUN in the Manage Paths dialog hags on "Loading" for several minutes.
This is a large cluster for our Core DB. I am not seeing any disk latency alerts yet I am still very nervous about this since VMware states only MRU is supported with 5.1. I have already set the P.R reservations....
I know you can change the PSP on the fly but nervous..
Thoughts on this anyone or am I just being to gun shy? What would happen if I leave it as is? User are not complains of performace issues?
I have also noticed when I click on some LUN in the Manage Paths dialog hags on "Loading" for several minutes.
This is a large cluster for our Core DB. I am not seeing any disk latency alerts yet I am still very nervous about this since VMware states only MRU is supported with 5.1. I have already set the P.R reservations....
I know you can change the PSP on the fly but nervous..
Thoughts on this anyone or am I just being to gun shy? What would happen if I leave it as is? User are not complains of performace issues?
ASKER
I totally understand...
I am trying to understand WHY the Manage Paths dialog box takes minutes to open on some LUNs that are already set to MRU. Have you seen this before
I am trying to understand WHY the Manage Paths dialog box takes minutes to open on some LUNs that are already set to MRU. Have you seen this before
ASKER
I believe I figured out my own problem. All Lun on the active node VM had the PR reservation set but the passive node does not which I believe explains why the "Manage Paths" dialog box hangs.
Here is my question. I am using MRU and not seeing any performance issues what is the down side of not settings this?
Here is my question. I am using MRU and not seeing any performance issues what is the down side of not settings this?
RR is what you should be normally using and is supported for Microsoft Failover Clusters with ESXi.
The downside of incorrect path policy, is loss of paths. Do you know the difference between MRU and RR ?
But it does depend on your SAN, and what your SAN vendor states is correct to use.
The downside of incorrect path policy, is loss of paths. Do you know the difference between MRU and RR ?
But it does depend on your SAN, and what your SAN vendor states is correct to use.
ASKER
Hi Hancock... Thanks for the reply. Yes I do the the difference between RR and MRU and with 5.1 only MRU is supported which is what we are using. My questions is that I noticed some LUN have the PR reservation setting to false which causes the Managed Paths page to hang on Loading. My question is if we are not seeing any problems in regards to disk latency what are the problems of leaving this until our next maintenance window
ASKER
Thank you for your patience with me Hancock.. So just as long as my PSP settings are correct for my version of ESXi and environment leave the PR reservation as false will pose no problem correct? Then why does Vmware recommend setting it to true..
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But, have you ever tested, multipath, and path failure, this would be my concern.
If you had a path outage, it may take several minutes, and the hang looking at paths, does not seem correct.