10 Replies Latest reply on Oct 20, 2014 1:47 PM by chrispaap

Datastore queue depth, are you out there?

jbiggley Oct 10, 2014 10:24 AM

ESX datastore queue depth

Virtualization engineers are curious lot, especially now that we've given them access to the pre-production VMAN environment. With all of the stats out there, of course they would find the *one* stat that I couldn't find in the tool.

Is the ESX datastore queue depth (current queue depth) captured and reported? I'm not looking for configured max queue length though it would be really cool to be able to compare the max queue length and current queue length.

Anyone?

Re: Datastore queue depth, are you out there?

jbiggley Oct 10, 2014 10:33 AM (in response to jbiggley)

For the record, I did find a statistic over at the VMware vSphere API Reference. Search All Properties for ScsiLUN, specifically the queuedepth property.
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Re: Datastore queue depth, are you out there?

chrispaap Oct 14, 2014 3:29 PM (in response to jbiggley)

We do not report on the queue depth property but the good news is we do collect the property (if configured) and we can gather the info with some manipulation.

If all your ESX hosts have queue depth set within VMware you can select each host in VMAN and select XML view. Under the LUN property, you can view queue depth
If you are trying to identify which servers have queue depth set a custom alert can be created using xpath to identify which servers have this property populated. If you need this let me know and I'll post the query details.
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- Re: Datastore queue depth, are you out there?
  
  jbiggley Oct 15, 2014 1:57 PM (in response to chrispaap)
  
  OK, that corresponds with DQLEN via ESXTOP, but can you really dazzle me and show me the historical view of the %USD for the same LUN? I couldn't find in the API reference, but that doesn't mean that it wasn't hiding in there some place.
  
  I assume that AQLEN is not available?
  
  VMware KB: Checking the queue depth of the storage adapter and the storage device
  
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- Re: Datastore queue depth, are you out there?
  
  jbiggley Oct 15, 2014 2:05 PM (in response to chrispaap)
  
  Interesting. I just dug into some of my hosts and I do not have queueDepth listed. Checked a bunch of hosts in the same cluster. Hosts are running 5.1.
  
  Any ideas?
  
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  - Re: Datastore queue depth, are you out there?
    
    chrispaap Oct 15, 2014 3:05 PM (in response to jbiggley)
    
    The system that has the property set in my environment is 5.5 so I will confirm that this is true for 5.1 as well. Another idea is to confirm if the HBA queue depth was set on the ESXi hosts (or if they were left to default). I used the following link to determine which HBA was installed on my ESXi servers and settings.
    
    VMware KB: Changing the queue depth for QLogic, Emulex and Brocade HBAs
    
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    - Re: Datastore queue depth, are you out there?
      
      jbiggley Oct 17, 2014 10:25 AM (in response to chrispaap)
      
      Any luck on confirming if this value is available via 5.1 chrispaap? I don't have access to the hosts myself and I'm trying to track down a VMware resource to help. You might be quicker though
      
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      - Re: Datastore queue depth, are you out there?
        
        chrispaap Oct 20, 2014 9:57 AM (in response to jbiggley)
        
        It looks like the customers that have this setting visible are on ESXi 5.5. Our lab setup only has data listed for the 5.5 hosts as well.
        
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        Re: Datastore queue depth, are you out there?
        
        jbiggley Oct 20, 2014 10:45 AM (in response to chrispaap)
        
        One more reason to get the virtualization team moving to 5.5. Thanks for the confirmation Chris. If you could post the xpath query into your answer above that would close the loop on this question.
        
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- Re: Datastore queue depth, are you out there?
  
  jbiggley Oct 17, 2014 11:31 AM (in response to chrispaap)
  
  Chris, could you post the xpath query details? I have a sneaky suspicion that there might not be any hosts in our production environment that have this value set.
  
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  - Re: Datastore queue depth, are you out there?
    
    chrispaap Oct 20, 2014 1:47 PM (in response to jbiggley)
    
    To identify any ESX hosts that have the queueDepth property populated it is possible to display 1 value per entity using a customer alert (in our case 1 computed value per host; the value can be a number or any string concatenated from multiple values – anything that is possible to express with XPath) . The notification value of the alert is the value displayed in the right side (the computed value) – currently the number of luns for the host which have the queueDepth value set. It is displayed in a way that is shown on the right side of the following image.
    
    In the example given STP-ESX-01 &STP-ESX-02 both have the queueDepth property set.
    
    Alert creation
    
    Scope Tab -
    Search Query = *
    Notification Tab
    count(/hostServer/lun/queueDepth/text())
    
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