T10-PI status for SCSI drive(SAS or SATA) and NVMe drives
If you are using SCSI drives and NVMe drives, you must verify T10-PI (protection
information) status for your drive. If the T10-PI protection is enabled for your drive, performing
the crypto-erase operation without verifying the protection information might make
the drive unusable until you re-initialize (overwrite) the protection information.
Verifying the T10-PI status information for SCSI drives
localhost:~ # sg_readcap -l /dev/sdg
Read Capacity results:
Protection: prot_en=1, p_type=1, p_i_exponent=0 [type 2 protection]
Logical block provisioning: lbpme=0, lbprz=0
Last logical block address=2424569855 (0x9083ffff), Number of logical blocks=2424569856
Logical block length=4096 bytes
Logical blocks per physical block exponent=0
Lowest aligned logical block address=0
Hence:
Device size: 9931038130176 bytes, 9470976.0 MiB, 9931.04 GB
localhost:~ #
In the output, in the line beginning with Protection, non-zero values for
prot_en or p_type indicate that protection (T10-PI) status is
either formatted or active. Presence of the string at the end of the line [type 2
protection], indicates that the protection is active.
Checking the Protection status of SCSI drives must be known because a
crypto-erase operation makes the drive unusable until the sectors are rewritten to
force valid PI. The format operation must be called with the same protection parameters. Otherwise,
the T10-PI protection is removed.
Verifying T10-PI status information for NVMe drives
nvme list command to display all namespaces. The Format column
indicates the sector block size. A compound value such as 4 KiB + 8 B indicates
that protection is formatted or active. The first value indicates the base block size, the second
value indicates the extra space that is reserved for the protection information.