Aug 18, 2014 John DeVito

Creating a Windows cluster: part 2 – Configuring shared disk in the OS

Windows cluster

Continuing along from the previous installment of this series (Using iSCSI to connect to Shared Storage) we’ll take a look at configuring the disks you have attached to your prospective cluster nodes.

In the previous article we used one of several methods for connecting to shared storage. Regardless of the method employed, you will continue preparing for your cluster by configuring the disks in the OS of each node. We should all know the steps to initializing disks and creating partitions, but I’ll go through them here, with an additional note or two about some things you’ll need to do in order to share these partitions between multiple cluster nodes.

A - First Node Disk ManagementOpen DISKMGMT.MSC from one of the prospective cluster nodes. You will see the shared disk displayed as Unknown, Offline, and Unallocated.
B - First Node Disk OnlineBring the disk online by right clicking in the area to the left of the disk representation and selecting Online from the context menu.
C - First Node Disk UnknownThe disk now shows up as Unknown, Not Initialized, and Unallocated.
D - First Node Initialize DiskRight click on the disk representation and select Initialize Disk from the context menu.
E - First Node Initialize Partition StyleSelect the disk(s) to initialize, select the partition style, and click OK.Important Note: The MBR style will not allocate the full size of partitions exceeding 2TB. If you have a partition greater than 2TB in size you must use the GPT partition style to use the entire partition size. If you use MBR on a partition greater than 2TB the partitioning will complete and you will not receive any error message, but you will only be able to access 2TB of the partition size. The rest will remain inaccessible.
F - First Node Create Simple VolumeNext create a volume and format it. In this example we are using a simple volume. This is basic windows which we probably all know, but I have the screenshots, so we’ll just run through the process. Right click on the disk representation and select New Simple Volume… from the context menu.
G - Simple Volume WizardClick Next at the Welcome Screen
H - Volume SizeClick Next to accept the default maximum size.
I - Volume LetterAssign the desired drive letter by choosing it from the dropdown box. In this example we are using L. Click Next to continue.
J - Format PartitionFormat the volume as NTFS and provide a volume label as desired. It is a good practice to provide a descriptive label, which we will see further on in the process. You can do a Quick Format or a Full Format as desired. A full format takes a longer amount of time to complete but is more detailed and marks any bad blocks on the disk, preventing them from being used during normal operations of the system. Click Next to continue.
K - Complete the Simple Volume WizardClick Finish to complete the creation of the volume.
L - First Node Disk ConfiguredWhen the disk(s) are configured you will see it/them in Disk Management as you would see any other disk. In our example you see the L: drive. You will most likely have multiple disks, so you would repeat the process for initializing and formatting all of the partitions you want shared between your cluster nodes.
M - First Node Take Disk OfflineOnce the disks are configured on the first node, take them offline. Right click the area to the left of the disk representation and select Offline from the context menu. this may seem odd, but shortly we will be bringing this disk up on the other cluster node and if both hosts have simultaneous access to the disk there will be conflicts and both nodes will not pass cluster validation tests, preventing the initial creation of the cluster.
N - Second Node Disk ManagementOn the second cluster node candidate open DISKMGMT.MSC
O - Second Node OnlineBring the disks online as you did with the first node by right clicking the area to the left of the disk representation and selecting Online from the context menu.
P - Second Node Missing Drive LetterThe disk(s) appear, formatted but with a missing drive letter.
Q - Second Node Rescan DisksSelect Rescan Disks from the Action menu as shown.
R - Second Node Wrong LetterThe disk(s) now appear with (a) drive letter(s), but they will be different from the ones you configured on the first node. They need to match.
S - Second Node Rename Drive LetterRight click each disk representation and select Change Drive Letter and Paths… from the context menu.
T - Change Drive LetterClick the drive icon and click Change.
U - Change Drive LetterChange the drive letter for the partition to match what you had configured on the first node by selecting it from the dropdown box. This is where you will realize the importance of clearly labeling your partitions. Such a practice will keep you from becoming confused when you are working with multiple partitions, especially if you have more than one with the same size. Click OK when you are done.
V - Changed Drive LetterNow the second node will have drive letters that match the ones on the first node.

Now the disks are ready for the creation of the cluster, which will be the next installment of the series on Creating a Windows Cluster. Until then, happy trails!