Raid level migration requirements, Under-reported disk capacity, Configuration file write error – Dell PowerVault MD3000 User Manual
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10
Information Update
NOTE:
Dell recommends backing up the disk group before modifying the
RAID level.
NOTE:
The number of disks in the disk group should meet its RAID level criteria.
RAID1 and RAID10 require an even number of disks. On the MD3000, RAID 5
requires a minimum of 3 disks and RAID 6 requires a minimum of 5 disks. You may
need to add free capacity to the disk group before changing the RAID level.
RAID Level Migration Requirements
Successful RAID Level Migration (RLM) requires that the appropriate
number of physical disks are present in your disk group. To perform RLM
from a RAID 1 or RAID 10 to an odd-number of physical disks (five or more)
in RAID 5, first add an even number of disks to the RAID 1 or RAID 10,
convert to RAID 5, then add another physical disk to make the count odd.
Under-Reported Disk Capacity
The unit Gigabyte (GB) is often used to refer to calculation of both 10
9
bytes
and 2
30
bytes. The MD Storage Manager calculates hard disk capacity in GB
using 2
30
bytes as compared to 10
9
that is used by hard disk manufacturers,
and therefore displays a smaller capacity than reported by the hard drive
vendor. There is no actual loss of available data capacity, and the MD3000
only reserves 512 MB (10
6
) of space per hard disk for meta-data usage.
Configuration File Write Error
Using the MD Storage Manager with Microsoft Windows Server 2008 or
Microsoft Windows Vista can result in a Configuration File Write
Error
. The MD Storage Manager will be unable to save any changes to the
configuration files. This error is seen when the application is run as a user
without Local Administrator privileges. MD Storage Manager requires Local
Administrator privileges for full functionality.
Workaround: This error can be bypassed by running the MD Storage
Manager with local administrator privileges. This can be set by right-clicking
the shortcut and clicking Run as Administrator. This setting can be made
permanent by modifying the shortcut properties and enabling Always run as
administrator.