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How to completely stop all IO on a MD3000 in a VMware environment

cspanther used Ask the Experts™
I have an MD3000 which uses a NX1950 as a front end to the ISCSI SAN.  The ISCSI SAN is what I use for the datastore in my vSphere 4 environment.  I have 3 VM Host servers that have an ISCSI connection to the MD3000.

I have to do a firmware update to the MD3000 which requires all IO to cease prior to me running the update.  How do I gracefully stop all IO to free up the MD3000 to do this update?  Can I just disable the NICs that run the ISCSI Initiator, or will that cause problems in VMWARE?  I have about 20 guest computers that use the MD3000 storage to host their VMDK files and I would rather not shut down all of the computers one by one.
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There are a 1000 ways to skin the technology cat.
I think you have no choice. As long as the md3000 data is being accessed by vms or other network devices, there will be IO.

I would recommend that you schedule downtime to bring your network offline during your SAN update.

Don't forget your good backup incase the firmware update goes belly up :)
Paul SolovyovskySenior IT Advisor
Top Expert 2008

I agree with Ryder.  Anytime you do a SAN update you should shutdown the ESX hosts or at least put them into maitnenance mode.  You should ensure a good backup off the SAN before you start


So, shut down the guests and then disable the ISCSI initiator before doing this?  This is what I was thinking, but I was hoping for a better way.
nappy_dThere are a 1000 ways to skin the technology cat.

Unfortunately no other way.  And yes shut down ALL communications to the MD3000 prior to the firmware upgrade. do not shut down the isci untill you have stopped ALL VM guest and server opreations.

Make sure you have a good backup.
Paul SolovyovskySenior IT Advisor
Top Expert 2008

This is why I like to shutdown the ESX hosts themselved, just to make sure nothing happens to the ESX side configuration.
Top Expert 2010

I would also recommend shutting ESX hosts down completely. But you may get by with suspending the VMs involoved rather than shutting them down.

Alternatively if you have additional datastores with capacity to hold the VMs you can storage vmotion them to the new datastore and accomplish the firmware upgrade with no down time. If this approach is pursued you should remove the datastores prior to maintenance (ensure they are empty first) and add them back when maintenance is complete.