Thanks for the inputs Martin.
We have observed that even though the HBA does not support DIX Type,
still the integrity attributes 'write_generate' and 'read_verify' are
set to 1 for the block devices.
a3560030:~ # cat /sys/class/scsi_host/host0/prot_capabilities
0
a3560030:~ # cat /sys/class/scsi_host/host1/prot_capabilities
0
a3560030:~ # cat /sys/block/sdc/integrity/write_generate
1
a3560030:~ # cat /sys/block/sdc/integrity/read_verify
1
Thanks and Regards,
Nikhil
On 14/12/24 4:00 am, Martin K. Petersen wrote:
The sysfs attributes related to block device integrity ,
write_generate and read_verify are enabled for the block device when
the parameter device_is_integrity_capable is disabled.
'device_is_integrity_capable' is set if storage device (media) is
formatted with PI.
That is completely orthogonal to 'write_generate' and 'read_verify'
which are enabled if the HBA supports DIX. If the HBA supports DIX Type
0, 'write_generate' and 'read_verify' are enabled even if the attached
disk is not formatted with PI.
I don't see any change in what's reported with block/for-next in a
regular SCSI HBA/disk setup. Will have to look at whether there is a
stacking issue wrt. multipathing.
