Users Guide

NOTE: Reconfiguring virtual disks typically impacts disk performance until the reconfiguration operation is complete.
Online Capacity Expansion (OCE) can be done in two ways:
1. If there is a single virtual disk in a disk group and free space is available, the capacity of a virtual disk can be expanded within
that free space. If multiple virtual disks exist within a common disk group, the capacities of those virtual disks cannot be
expanded.
NOTE: Online capacity expansion is allowed on a disk group with a single virtual disk that begins at the start of the
physical disk. It is not allowed when there is a free space at the beginning of a disk.
2. Free space is also available when the physical disks of a disk group are replaced by larger disks using the replace member
feature. The capacity of a virtual disk can also be expanded by performing an OCE operation to add more physical disks.
RAID level migration (RLM) refers to changing a virtual disk’s RAID level. Both RLM and OCE can be done simultaneously so
that a virtual disk can simultaneously have its RAID level that is changed and its capacity increased. When an RLM or an OCE
operation is complete, a reboot is not required.
CAUTION: Do not attempt disk migration during RLM or OCE operations. This causes loss of the virtual disk.
NOTE: If an RLM or an OCE operation is in progress, then an automatic drive rebuild or copyback operation will not start
until the operation is complete.
NOTE: 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.
NOTE: The controller changes the write cache policy of all virtual disks to write-through until the RLM or OCE operation is
complete.
Features of PowerEdge RAID Controller 11 21