Updating Storage drivers on Host

[prutter]

I installed a host on a Dell T420 and added a couple VM's to it and now having a bit of a storage issue.  Read/writes seem to be very slow and after talking to Dell they tell me that I needed to use their ESXi Build since it has their controller drivers build in.  The issue is that this Host and the few VM's are in production and I would prefer finding an answer without having to blow away the entire host and VM's.  ESXi is installed on mirrored SD cards and the Storage that we are using is internal to the 420 setup in a RAID 5 config. My thought were, since it's installed on the SD cards that I could get another T420 (which I have) that has the same controller, install VMWARE on that system then put them in the production box,  rescan the adapters for storage and then import my VM's.  That's my short version of what I'm thinking.  A couple questions I have are...is that possible or is there a way to update the drivers in the original system without issues?  Any comments or suggestions are welcome.  Thanks!

Perry  

[aaronwsmith]

Does Dell have a VIB depot similar to vendors like HP and VMware?  Or provide a site where you can download their controller driver VIB?

If so, you could download the VIB for the driver they are bundling in their custom ESXi image and install it from the command line on the existing host.  Likely should install just fine.  Vendors use the same hypervisor code and just add their drivers and optional software components.

You could use that extra T420 to install Dell's custom image, then run "esxcli software vib list" on both machines and compare what Dell is bundling vs. what you already have.  Might help establish confidence in installing their driver in-place on the server you already built.

[prutter]

I can certainly find out if they do.  Their tech support guys aren't very good and they always need to ask up the chain.   Do you see an issue with trying to use a duplicate machine to install ESXi on the SD cards?  The Dell tech says they don't recommend that since there is a possibility on software corruption.  I don't see how?

[aaronwsmith]

VMware supports ESXi 5.x installation to SD Cards.  They just need to meet same requirements for ESXi as SATA/SAS drives.  See VMware KB: Installing ESXi 5.x on a supported USB flash drive or SD flash card so I'm not sure what corruption issue they feel is at risk.

Check the BIOS on your existing box however, ensure power management is set to Maximum Performance.  I've read some people experienced better performance on their ESXi installations on Dell hardware with mirrored SD cards after making that change.

[aaronwsmith]

Also, run this command on the existing ESXi host to see if the SD card is being identified as a SSD:

esxcli storage core device list

The output will include information on whether the device is identified as a "SSD" or not.

Also, run these commands and post here to help us see which driver is being used for the SD card storage:

(Will show storage adapters and associated driver) esxcli storage core adapter list

(Will show storage paths and which adapter is associated with that path) esxcli storage core path list

[prutter]

I'm guessing that the only options I have are 1. to do a total reinstall of the entire system (which I prefer not to do) or 2. Get a duplicate system with 2 SD cards and reinstall ESXi on them with the dell Build and put them in the current system.

Can anyone else give their opinions about option 2??? 

[aaronwsmith]

You're operating under the assumption that the only fix is to install whatever driver Dell is insisting their ESXi image only includes.

I'm wondering what that driver is, and what driver is currently claiming control of the SD cards currently?  That's where my questions about getting info on your storage config with those commands was going.

I'd still be confident you can install the driver onto the existing system you build, assuming you can get a copy of it to install.

[prutter]

It's not the SD cards Im having issues with, it's the RAID 5 storage that we are using for the VM environment.  All the VM Storage is on 5 SAS drives that are internal to the Dell.  It is that controller that seems to be having the issue.  Very slow reads / writes to that array.  

[prutter]

One other question related to this post.  If I reinstall the OS on the SD cards that are in the system is there any chance of data corruption on the Internal RAID 5 Array where my vm's currently reside??  It appears to be my only option an need to know worse case scenarios.  Any input is appreciated.  Thanks.

[aaronwsmith]

Sorry that I misunderstood what you were originally describing.  The only way you run the risk of destroying/corrupting your VMs is if you selected the RAID5 logical volume by mistake for installing ESXi onto vs. the SD mirror cards.  Otherwise the installer does not touch the other volumes.

You'd run the same risk if you were installing ESXi 5 on a server with FC attached storage; the installer would see all the SAN volumes and present them as possible locations to perform the install.  It's just a matter of selecting the correct location to install the ESXi image.

[prutter]

Well I thought so but just needed clarification.  I have to go to the clients tomorrow and reinstall with the Dell ESXi Build.  Don't want to but have to.  Thanks again for all the input.  Really appreciate it. 

[aaronwsmith]

Hope it goes well for you.  Assuming you're going to install Dell's custom ESXi image?  Let us know if it resolves the performance issue.

[prutter]

I certainly will. Thanks again!!!  I will leave this post open until I reply. 

[prutter]

Well Aaron, everything came out just the way I thought and the way you said.  Did the reinstall, imported the VM's from the storage and all is good.  The read writes on the disks are great.  Thanks for all the response.  Much appreciated.

[aaronwsmith]

Glad to hear it!  And at least gives some credit to Dell support that their solution was correct for installing their custom image.  HP has a similar situation where they promote using their custom ESXi image and drivers, but I personally don't opt for that path for a few different reasons.  Suffice to say that if you had wanted you could create your own ESXi image and incorporate the driver(s) Dell is providing, but it's probably not worthwhile if you don't have any other reasons for making this kind of effort.