VIOS 3.1.1 - Increase # of NPIV’s per FC port to 255?
I noticed that starting with VIOS 3.1.1, there is meant to
be an increased number of NPIVs per FC port i.e. increase from 64 to 255.
"An increased number of NPIVs allowed per Fibre
Channel port on the 32 GB Fibre Channel HBA. The current limit is 64, and more
NPIVs per port will provide better utilization, density, and efficiency."
I was left wondering if this increase is expected to be
available without configuration or not?
Looking at my VIOS 3.1.1.10 system, lsnports
still reported 64 and not 255. However, I'm using 16GB FC adapters not 32GB.
$
ioslevel
3.1.1.10
$ lsnports
name physloc fabric tports aports swwpns awwpns
fcs0 U78C9.001.WZS00BP-P1-C12-T1 1
64 62 3088
3080
fcs1 U78C9.001.WZS00BP-P1-C12-T2 1
64 61 3088
3077
fcs2 U78C9.001.WZS00BP-P1-C6-T1 1
64 64 3088
3086
fcs3 U78C9.001.WZS00BP-P1-C6-T2 1
64 64 3088
3086
In the past, on older VIOS versions, I was aware of an
(unsupported) way to increase this value that required us to modify a
"hidden" ODM attribute, max_npivs i.e.
$
oem_setup_env
#
chdev -l fcs0 -a max_npivs=128-P
fcs0
changed
#
exit
$
shutdown -restart
After reboot:
$ lsnports
name physloc fabric tports aports swwpns awwpns
fcs0 U2C4E.001.DBJ8765-P2-C5-T1 1
128 127
2048 2045
fcs1 U2C4E.001.DBJ8765-P2-C5-T2 0
64 64 2048
2048
In talking with the development support team I was informed that the
default max value for max_npivs is still 64, for
compliance with older supported HBAs (NPIV capable).
#define
DEFAULT_MAX_NPIVS 64
And, when you use 16 Gbps or lesser adapters, the maximum limit of
64 still applies. To enable the new maximum value for a 32Gbps adapter, the
below action is required:
$
chdev -dev fcs# -perm -attr max_npivs=255
$
shutdown -restart
This change is supported with 32 Gbps FC adapters. Above action
are not dependent on VIOS level 2.2.6.x or 3.1.x.
Note that there is also a known defect 1074787 LSNPORTS TPORTS
VALUE MAY CHANGE UNEXPECTEDLY ON VIOS.
APAR IJ12857 72M (3.1.0.21)
APAR
IJ12914 72Q (3.1.1.0)
APAR
IJ12861 61r (2.2.6.41)
https://www-01.ibm.com/support/docview.wss?uid=isg1IJ12857
http://www-01.ibm.com/support/docview.wss?uid=isg1IJ12914
https://www-01.ibm.com/support/docview.wss?uid=isg1IJ12861
Related: Maximum value for num_cmd_elems on AIX/VIOS https://www.ibm.com/support/pages/node/1107759