Brocade Fabric OS Encryption Administrator's Guide v7.1.0 (53-1002721-01, March 2013)

Table Of Contents
290 Fabric OS Encryption Administrators Guide (SKM/ESKM)
53-1002721-01
AIX Considerations
5
AIX Considerations
For AIX-based PowerHA SystemMirror host clusters, the cluster repository disk should be defined
outside of the encryption environment.
Ensure that Dynamic Tracking is set to “Yes” for all Fibre Channel adapters on the AIX system.
Enabling a disabled LUN
When Metadata is found on the LUN, but current LUN state is indicated as cleartext or is being
converted from encrypt to cleartext, the LUN is disabled and the LUN status displayed by the LUN
Show CLI command is Internal EE LUN state: Encryption disabled <Reason Code>.
The disabled LUN can be enabled by invoking the enable LUN command.
switch:admin> cryptocfg --enable -LUN <crypto target container name> <LUN Num>
<InitiatorPWWN>
Disk metadata
If possible, 32 bytes of metadata are added to every block in LBA range 1 to 16 for both the native
Brocade format and DF-compatible formats. This metadata is not visible to the host. The Host I/Os
for the metadata region of the LUN are handled in the encryption switch software, and some
additional latency should be expected.
NOTE
For encrypted LUNs, data in LBA 0 will always be in cleartext.
Tape metadata
One kilobyte of metadata is added per tape block for both the native Brocade format and
DF-compatible formats. Tape block size (as configured by host) is modified by the encryption device
to accommodate 1K metadata per block. A given tape can have a mix of compressed and
uncompressed blocks. Block lengths are as follows.
Tape data compression
Data is compressed by the encryption switch or blade before encrypting only if the tape device
supports compression, and compression is explicitly enabled by the host backup application. That
means if the tape device supports compression, but is not enabled by the host backup application,
then compression is not performed by the encryption switch or blade before encrypting the data.
However, if the backup application turns on compression at the tape device and does not turn it off
Encrypted/Compressed
Tape Block Format
Compressed and encrypted tape block data + 1K metadata + ASCII 0 pad = block
length of tape.
Encrypted Tape Block
Format (No Compression)
Encrypted tape block data + 1K metadata = block length of tape.