vxdmpadm path activate weirdness
Just stumbled upon a strange behavior of vxdmpadm which requires further investigation.
The problem I’ve faced with during an attempt to set certain path “active” to loadbalance the data flow on HDS between its controllers. The built-in help clearly states that:
# vxdmpadm setattr help
vxdmpadm setattr path
pathtype=
pathtype can be either:
active
nomanual
nopreferred
preferred [priority=]
primary
secondary
standby
So I dully expected it to work as declared but instead I got the following error:
# vxdmpadm getsubpaths ctlr=c2 NAME STATE[A] PATH-TYPE[M] DMPNODENAME ENCLR-TYPE ENCLR-NAME ATTRS ================================================================================ c2t50060E800042A5F0d81s2 ENABLED(A) PRIMARY hds9500-alua0_0051 HDS9500-ALUA hds9500-alua0 - c2t50060E800042A5F3d81s2 ENABLED SECONDARY hds9500-alua0_0051 HDS9500-ALUA hds9500-alua0 - c2t50060E800042A5F0d82s2 ENABLED(A) SECONDARY hds9500-alua0_0052 HDS9500-ALUA hds9500-alua0 - c2t50060E800042A5F3d82s2 ENABLED PRIMARY hds9500-alua0_0052 HDS9500-ALUA hds9500-alua0 - # vxdmpadm getsubpaths ctlr=c3 NAME STATE[A] PATH-TYPE[M] DMPNODENAME ENCLR-TYPE ENCLR-NAME ATTRS ================================================================================ c3t50060E800042A5F1d81s2 ENABLED(A) PRIMARY hds9500-alua0_0051 HDS9500-ALUA hds9500-alua0 - c3t50060E800042A5F2d81s2 ENABLED SECONDARY hds9500-alua0_0051 HDS9500-ALUA hds9500-alua0 - c3t50060E800042A5F1d82s2 ENABLED(A) SECONDARY hds9500-alua0_0052 HDS9500-ALUA hds9500-alua0 - c3t50060E800042A5F2d82s2 ENABLED PRIMARY hds9500-alua0_0052 HDS9500-ALUA hds9500-alua0 - # vxdmpadm setattr path c2t50060E800042A5F3d82s2 pathtype=active VxVM vxdmpadm ERROR V-5-1-10357 Invalid argument or attribute specified.
Looks like I’ll need to investigate deeper to find the culprit but as a workaround just disabled the second path to force a failover to another one I tried to make active.
Update.
As always RTFM rules and I must admin that my apprehension, that with option one could change the state listed in the second column to active, was completely wrong. In the man page it’s lucidly written that pathtype=active is used to change a standby path to active.
# vxdmpadm setattr path c2t50060E800042A5F3d81s2 pathtype=standby # vxdmpadm getsubpaths NAME STATE[A] PATH-TYPE[M] DMPNODENAME ENCLR-NAME CTLR ATTRS ================================================================================ c2t50060E800042A5F3d81s2 ENABLED SECONDARY hds9500-alua0_0051 hds9500-alua0 c2 STANDBY # vxdmpadm setattr path c2t50060E800042A5F3d81s2 pathtype=active # vxdmpadm getsubpaths NAME STATE[A] PATH-TYPE[M] DMPNODENAME ENCLR-NAME CTLR ATTRS ================================================================================ c2t50060E800042A5F3d81s2 ENABLED SECONDARY hds9500-alua0_0051 hds9500-alua0 c2 -
Since in my case the path was already active it would be strange to make it active for the second time and as a result I got the error. So actually there were two options:
- Use vxdmpadm disable
- Use vxdmpadm setattr path pathtype=standby/active
So, folks, never underestimate the documentation. ;-)