Sun Microsystems StorEdge T3+, Installation And Configuration Manual

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122 Sun StorEdge T3+ Array Installation and Configuration Guide • April 2002
Creating and Labeling a Logical Volume
You must set the RAID level and the hot-spare disk when you create a logical
volume. For the Solaris operating system to recognize a volume, it must be labeled
with the
format
or
fmthard
command.
Caution –
Removing and reconfiguring a logical volume will destroy all data
previously stored there.
Setting the LUN Reconstruction Rate
Note –
When a failed drive is disabled, the volume is operating without further
redundancy protection, so the failed drive needs to be replaced as soon as possible.
If the volume has a hot spare configured and that drive is available, the data on the
disabled drive is reconstructed on the hot-spare drive. When this operation is
complete, the volume is operating with full redundancy protection, so no loss of
data occurs if another drive in the volume fails.
After a drive has been replaced, the original data is automatically reconstructed on
the new drive. If no hot spare was used, the data is regenerated using the RAID
redundancy data in the volume. If the failed drive data has been reconstructed onto
a hot spare, after the reconstruction has completed, a copy-back operation begins in
which the hot spare data is copied to the newly replaced drive.
You can also configure the rate at which data is reconstructed, so as not to interfere
with application performance. Reconstruction rate values are low, medium, and high
as follows:
■
Low is the slowest and has the lowest impact on performance
■
Medium is the default
■
High is the fastest and has the highest impact on performance
Note – Reconstruction rates can be changed while a reconstruction operation is in
process. However, the changes don’t take effect until the current reconstruction has
completed.