When dmp_native_support is set to on, commands hang for a long time on SAN failures (3084656)

Last published : Sep 23, 2026
When dmp_native_support is set to on, on SAN failures, commands that do I/O operations to the root file system or I/O to disks that contain the root pool may hang for about 1-5 minutes. The commands include commands like "zpool status", or telnet initiated to connect the system. The hang is seen because the drivers below the DMP layer take more time to report the I/O failure when some of the paths to the disk containing the root pool are disconnected. This situation should not lead to any root pool data corruption.
Workaround :
This hang cannot be avoided but the hang time can be reduced by tuning the following parameters
To tune the parameters
  1. In the /kernel/drv/fp.conf file, set
    fp_offline_ticker=15
    1. In the /kernel/drv/fcp.conf file, set
    fcp_offline_dely=10
  2. Reboot the sytem to apply the changes.
These steps reduce the hang time to a maximum of 1 minute.