Compellent Disk Management with PowerShell: Windows Server 2008 Disks

Posted 3 CommentsPosted in Compellent, PowerShell, Storage

I was provisioning some Compellent storage today for a a series of tests that I am working on that required 62 volumes per server on two different servers.  These volumes are multi-pathed and although using the Compellent Storage Center GUI is easy and straightforward, completing this process would take a long time doing by hand and seemed fit to be automated using the Compellent Storage Center Command Set for Windows PowerShell.

I wrote a script a while back that handles my provisioning for me; in this case a couple of mount point root volumes followed by data volumes that would be accessed by mount point instead of drive letter.  The script is flexible enough to handle different volume counts and whether or not drive letters would be used, but the catch was I had only used it with Windows Server 2003. 

I tried to run the script this morning and found a flaw pretty quickly.  The volume was created on the Storage Center, mapped properly across the available paths, but when the script tried to initialize the volume in Windows, it would come back as “failed to initialize” with VDS error code 80070013.  This VDS error code indicates that the “media is write-protected”.  How could that be on a new volume?

Windows 2008 changed the way disk management is handled especially around delivery of the disk to the server.  By default, a disk mapped to a Windows 2008 server via VDS will be delivered in offline mode and also read-only.  In Windows Server 2008 there is a policy new to Windows related to SAN disks. This "SAN policy" determines whether a newly discovered disk is brought online or remains offline, and whether it is made read/write or remains read-only.  By default, the “Offline All” policy is set.  This means All newly discovered disks remain offline and read-only.  You can change this default policy in DISKPART by running the SAN POLICY=<POLICY NAME> from a DISKPART command prompt.


changing the default SAN policy in DISKPART


You can read more here, but in the meantime, the fix for this from a scripting perspective is quite simple.  The inability to initialize the disk because it was read-only was due to the SAN policy which presented the volume in a read-only fashion (and offline too).  We can change the disk attribute  of the volume so it is not read-only and then we can bring the disk online so it is usable.  Here is a sample of how to use the Command Set to change the read-only attribute and the state of the drive:

Write-Output "Bringing Disk Online..."
Set-DiskDevice -SerialNumber $scvolume.SerialNumber -Online
Set-DiskDevice -SerialNumber $scvolume.SerialNumber -ReadOnly:$false

$scvolume is a variable that refers to the volume object that is created when we create a new volume using New-SCVolume.  The serial number is used to identify the disk mapped to the Windows Server.  It is also important to note that although the “Online” and “ReadOnly” switches come from the same cmdlet, these must be executed separately as they are in the sample. (Thanks for that important tidbit, Sean!)

Windows 2008 Hyper-V Resource Kit Now Available

Posted Leave a commentPosted in Compellent, Storage, Virtualization

On June 10, Microsoft Press published the new “Windows 2008 Hyper-V Resource Kit” by Robert Larson and Janique Carbone.

For the past year, Shane Burton a fellow Microsoft Product Specialist here at Compellent, and myself have been working with Robert and Janique on this project and providing content, particularly “Notes from the Field” for the book, while our Compellent Marketing Alliance partner, John Porterfield kept us in line.

Compellent is a project sponsor at the Microsoft Partner Solution Center and provided Robert and Janique access to a Compellent Storage Center for testing storage-related scenarios that are included in the book. Compellent users will recognize a lot of the screenshots which were taken directly from the Storage Center Manager.

Shane and I are proud to be contributing authors on this project. We hope the Windows 2008 Hyper-V Resource Kit will prove to be an invaluable reference for administrators and IT pros who are responsible for the architecture, design, implementation and ongoing maintenance of a Hyper-V environment.

The book is now available at Amazon and Barnes & Noble.

The Case of the Missing Interview

Posted Leave a commentPosted in Compellent, PowerShell

Even though we had a number of technical difficulties, I really enjoyed the interview with Jon and Hal over at the Powerscripting Podcast.  I was excited to listen to the playback to the interview which should’ve been available a few days after we recorded the live show, but the interview went missing from what I hear, so Episode 54 was MIA.  Our people are working on seeing if we can reschedule the interview for another show to take another run at it.

Powerscripting Podcast

Posted Leave a commentPosted in Compellent, PowerShell

I will be the guest for an interview on the Powerscripting Podcast, a Powershell podcast designed to help people learn Windows PowerShell.

I will be on to discuss the Compellent Command Set for Windows PowerShell, our free offering for customers who want the ability to manage their Compellent Storage Center via script, or automate administration processes, a lot of which I will talk about in the interview.

This is a live show and the hosts will take questions during the broadcast, So, tune in Thursday night (January 8) at 9 AM EST (8 PM CST)!