CLI Guide

Examples Show FDE information.
# show fde-state
Basetypes
fde-state
status
See also
clear fde-keys
set fde-import-key
set fde-lock-key
set fde-state
show fenced-data
Description
Shows information about fenced data blocks in the storage system. The command will show
information for all fenced blocks by default, or you can use parameters to filter the output.
Fenced data blocks are blocks of data on disk which, for either of the following reasons, cannot be
recovered and have been lost:
● Typically, fenced data occurs when a disk in a non-fault-tolerant disk group detects an
unrecoverable media error.
● Fenced data can also occur if multiple unrecoverable blocks are detected which exceed the
capacity of the RAID error-recovery algorithms.
Unrecoverable data blocks are “fenced” by marking them unreadable by the storage system. A data
block remains fenced until the host writes the block, at which time it is again accessible.
For NRAID and RAID 0, fenced data is not tracked. Errors are returned directly during host reads.
For RAID 1 and 10, fenced blocks correspond with the data blocks where unrecoverable errors are
detected, normally when a disk group is not fault tolerant and the remaining good disk has a media
error.
For RAID 3, 5, 6, 50 for linear storage or 5, 6, and ADAPT for virtual storage, a single unrecoverable
error detected while not fault tolerant can result in two or more blocks being fenced. This is because
each parity block protects multiple data blocks. Thus, for RAID 3, 5, and 50, if a block returns an
unrecovered error during reconstruction, that block is lost (because it cannot be read). The block
being reconstructed is also lost because there is not enough information to reconstruct the data for
that block. RAID 6 and ADAPT will similarly mark multiple bad blocks if a combination of failed disks
and media errors results in unrecoverable data.
When the controller module fences data, it logs events 542 and 543.
Minimum role
monitor
Syntax
show fenced-data [all]
[disk-groups disk-groups]
[vdisks vdisks]
[volumes volumes]
Parameters
all
Optional. Shows information about all fenced data blocks.
[disk-groups disk-groups]
Optional. The names or serial numbers of disk groups for which to show fenced data block
information. A name that includes a space must be enclosed in double quotes.
[vdisks vdisks]
Optional. The names or serial numbers of disk groups for which to show fenced data block
information. A name that includes a space must be enclosed in double quotes.
204 Alphabetical list of commands