This blog shows step by step procedure to expand an existing SAN LUN
on a Windows 2003 server presented from an EMC CX4-240 storage array. In this
example, I expanded a 2 TB LUN on a Windows 2003 server to 3 TB.
Pre-requisites:-
- EMC Unisphere client
- Login credentials for the Unisphere client
- Admin Login credentials for the Windows server (needed to run diskpart)
- The OS should support the LUN expansion (Different operating systems have limitation for the file system size so please check the operating system guide for maximum supported disk size)
1. As you can see in the diagram below, the
existing LUN size is 2 TB. In order to expand the LUN beyond the 2 TB limit on
a Windows 2003 server, make sure that the disk type is GPT (GUID Partition
Table).
2. Login to the EMC Unisphere Client and select the
RAID Group that contains the LUN. In our example here, it is RAID Group 15 and
LUN 150.
3. Right click the RAID Group and select “Create LUN” option.
4. In the new window that opens up, type the “User
Capacity” as 1000 GB. You can either specify the LUN ID or can leave it to the
default value. Click apply and close the window.
5. So now we have a new LUN (LUN 0 in our example)
of capacity 1 TB.
6. After the new LUN has been created, right click
the original LUN that you wanted to expand (LUN 150 in our example) and select
“Expand” option.
7. The “Expand Storage Wizard” will open up. Click
“Next” to begin.
8. There are two ways in which the new LUN can be
used to expand the current LUN capacity.
a.
Striping: The data on the existing LUN is
stripped across the new LUN.
b.
Concatenation: It simply adds additional
capacity to the existing LUN without stripping the data across the two LUNs.
Since my aim is to just gain additional capacity on my existing
LUN, I will choose the “Concatenation” option.
9. Click “Next”
10 .
Click “Next” again.
11.
In the new Window that opens up, click “Yes”.
Unisphere will give this warning message if the new LUN size exceeds 2 TB.
12.
In the next Window that opens up, mention the
size of the new Concatenated LUN.
14.
On the Summary page, click “Finish”.
15.
Now login to the server where you wanted to
expand the disk. Open Disk Management. Right click disk management and select “Rescan
Disks”.
In our example, we are expanding G: from 2 TB to 3 TB.
a. List disk
b.
Select disk
<disk #>, where <disk #> is the disk number of the LUN that we
want to expand. (Disk 3 in our example)
c.
Select volume
<volume #>, where <volume #> is the volume that we want to
expand. (Volume 1 in our example)
d. Type
“Extend”
e. You
will see that the size of the new LUN is now 3 TB.
