Users Guide

Change Controller Properties Change Policy
Manage Physical Disk Power Slow Initialize
Convert to RAID Capable Disks Fast Initialize
Convert to Non-RAID Disks Replace Member Disk
Change Controller Mode
OCE and RLM Restrictions or Limitations
Following are the common limitations for OCE and RLM:
• OCE/RLM is restricted to the scenario where the disk group contains only one VD.
• OCE is not supported on RAID50 and RAID60. RLM is not supported on RAID10,RAID50 and RAID60.
• If the controller already contains the maximum number of virtual disks, you cannot perform a RAID level migration or capacity
expansion on any virtual disk.
• The controller changes the write cache policy of all virtual disks undergoing a RLM/OCE to Write-Through until RLM/OCE is
complete.
• Reconfiguring Virtual Disks typically impacts disk performance until the reconfiguration operation is complete.
• The total number of physical disks in a disk group cannot exceed 32.
• If any background operation (like BGI/rebuild/copyback/patrol read ) is already running on the corresponding VD/PD then
Reconfiguration (OCE/RLM) is not allowed at that time.
• Any kind of disk migration when Reconfiguration (OCE/RLM) is on progress on drives associated with VD causes reconfiguration to
fail.
• Any new drive added for OCE/RLM becomes part of the VD after reconstruction completes. But State for those new drive changes
to Online just after reconstruction starts.
Cancel Initialization
This feature is the ability to cancel the background initialization on a virtual disk. On PERC controllers, the background initialization of
redundant virtual disk starts automatically after a virtual disk is created. The background initialization of redundant virtual disk prepares the
virtual disk for parity information and improves write performance. However, some processes such as creating a virtual disk cannot be run
while the background initialization is in progress. Cancel Initialization provides the ability to cancel the background initialization manually.
Once cancelled, the background initialization automatically restarts within 0 to 5 minutes.
NOTE:
Background initialization is not applicable for RAID 0 virtual disks.
Managing virtual disks using web interface
1. In the iDRAC web interface, go to Storage > Overview > Virtual Disks > Advanced Filter.
2. From the Virtual Disks, select the controller for which you want to manage the virtual disks.
3. For one or more Virtual Disks, from each Action drop-down menu, select an action.
You can specify more than one action for a virtual drive. When you select an action, an additional Action drop-down menu is displayed.
Select another action from this drop-down menu. The action that is already selected does not appear in the additional Action drop-
down menus. Also, the Remove link is displayed next to the selected action. Click this link to remove the selected action.
• Delete
• Edit Policy: Read Cache — Change the read cache policy to one of the following options:
• No Read Ahead — Indicates that for the given volume, no read ahead policy is used.
• Read Ahead — Indicates that for the given volume, the controller reads sequentially ahead of the requested data and stores
the additional data in cache memory, anticipating a data requirement. This speeds up sequential data reads, but there is less
improvement when accessing random data.
• Adaptive Read Ahead — Indicates that for the given volume, the control uses the Read-Ahead cache policy if the two most
recent disks accesses occurred in sequential sectors. If the read requests are random, the controller returns to No Read Ahead
mode.
• Edit Policy: Write Cache — Change the write cache policy to one of the following options:
• Write Through — Indicates that for the given volume, the controller sends a data transfer completion signal to the host
system when the disk subsystem has received all the data in a transaction.
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Managing storage devices