Administrator Guide

10. If you want to change the repository expansion policy or warning threshold, click View advanced repository settings.
• Repository expansion policy – Select either Automatic or Manual. When the consumed capacity gets close to the physical
capacity, you can expand the physical capacity. The MD Storage Manager can automatically expand the physical capacity, or you
can do it manually. If you select Automatic, you also can set a maximum expansion capacity. The maximum expansion capacity
allows you to limit the virtual disk’s automatic growth below the virtual capacity. The value for the maximum expansion capacity
must be a multiple of 4 GB.
• Warning threshold – In the Send alert when repository capacity reaches field, enter a percentage. The MD Storage
Manager sends an alert notification when the physical capacity reaches the full percentage.
11. Click Finish.
The Confirm Initialization of Thin Virtual Disk window is displayed.
12. Read the warning and confirm if you want to initialize the thin virtual disk.
13. Type yes, and click OK.
The thin virtual disk initializes.
Changing a thin virtual disk to a standard virtual disk
If you want to change a thin virtual disk to a standard virtual disk, use the Virtual Disk Copy operation to create a copy of the thin virtual
disk. The target of a virtual disk copy must always be a standard virtual disk.
Utilizing unmapping for thin virtual disk
In version 8.25, the Thin Provisioning feature is enhanced to support the UNMAP command, through the command-line interface. Any
thinly provisioned virtual disks that are configured on a storage array before an upgrade to version 8.25 are still available after the upgrade
and supports the UNMAP command. However, in previous versions of the MD Storage Manager operating system, thinly provisioned
virtual disks are reported to the host operating systems as standard virtual disks.
Existing thinly provisioned virtual disks in a storage array that you upgrade to version 8.25 are still reported to the host operating system
as standard virtual disks until, you use the command-line interface to set the reporting status to thin. Thinly provisioned virtual disks that
you configure after upgrading to version 8.25 are reported to the host operating systems as thinly provisioned virtual disks.
Enabling unmap thin provisioning for thin virtual disk
If you are upgrading to MD Storage Manager operating system (controller firmware) version 08.25, and you have thinly-provisioned virtual
disks on your storage array that you want reported to host operating systems as thinly-provisioned, complete the following steps:
• For a single thinly-provisioned virtual disks, enter set virtual disk["virtualdiskName"]
hostReportingPolicy=thin.
• For multiple thinly-provisioned virtual disks, enter set virtual disks ["virtualdiskName1" ...
"virtualdiskNameN"] hostReportingPolicy=thin.
To make sure that the change in reporting policy is recognized, reboot any hosts that use any virtual disks whose reporting status is
changed.
When you enable reporting of thinly-provisioned virtual disks to host operating systems, the host can subsequently use the UNMAP
command to reclaim unused space from thinly-provisioned virtual disks.
Choosing an appropriate physical disk type
You can create disk groups and virtual disks in the storage array. You must select the capacity that you want to allocate for the virtual disk
from either unconfigured capacity, free capacity, or an existing disk pool available in the storage array. Then you define basic and optional
advanced parameters for the virtual disk.
With the advent of different physical disk technologies, it is now possible to mix physical disks with different media types and different
interface types within a single storage array.
Physical disk security with self encrypting disk
Self Encrypting Disk (SED) technology prevents unauthorized access to the data on a physical disk that is physically removed from the
storage array. The storage array has a security key. Self encrypting disks provide access to data only through an array that has the correct
security key.
Disk groups, standard virtual disks, and thin virtual disks
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