NEC 140He - Manual (Page 267)

9-9
DISK lamps
When the hard disk drives are in the disk array configuration, you can restore the state before an error using the
auto-rebuild feature that stores the data in the old hard disk drive into a new one.
The auto-rebuild feature may be enabled or disabled depending on the RAID level.
Auto-rebuild is automatically carried out when you hot-swap a failed hard disk drive with a new one (replace the disk
while the server is powered). While auto-rebuild is in progress, the DISK lamp flashes green and amber alternatively to
indicate it.
IMPORTANT: When auto-rebuild fails, the DISK lamp lights in amber. Remove and
install the hard disk drive again to restart auto-rebuild. (If the disk array monitoring utility
is installed, check the indication of the utility.)
Observe the following notes for auto-rebuild.
„ Do not power off the server in the period between a hard disk drive error and completion of auto-rebuild.
„ When you removed a hard disk drive, wait at least 90 seconds before installing the hard disk drive back again.
„ Do not replace another hard disk drive while rebuilding is in progress. (The DISK lamp flashes green and
amber alternatively while rebuilding the hard disk drive.)