SDD - addpaths command

[ogniemi]

the SDD drivers are:

devices.sdd.53.rte 1.6.0.8 COMMITTED IBM Subsystem Device Driver
devices.sdd.53.rte 1.6.0.8 COMMITTED IBM Subsystem Device Driver


Case: I have two systems sharing ESS LUN. The LUN is reserved on node01 now. On node01 the LUN is "visible" on two paths (lsvpcfg outputs):

vpath2 (Avail pv datavg) 54564007 = hdisk4 (Avail ) hdisk7 (Avail )

On node02 I only one path is avaialble:

vpath2 (Avail pv datavg) 54564007 = hdisk4 (Avail )


After cfgmgr on node02 (when datavg was online on node01) the hdisk7 "appeared" but vpath2 still has only one path (Avail)

Q: Is it possible safely configure second path in vpath2 on node02 without varyoffing datavg on node01?

 

[p5wizard]

Try addpaths command on node02. If the disk is reserved on node01, it probably won't work as I'm assuming addpaths needs to open() the hdisk device to find out which disk belongs to which vpath, but it can't harm either.



HTH,

p5wizard

 

[ogniemi]

I need to be sure it will work.

the documentation to sdd says:

"Dynamically adding paths to SDD vpath devices This section shows you how
to add paths to SDD vpath devices with the addpaths command. The addpaths
command allows you to dynamically add more paths to SDD vpath devices when
they are in the Available state. It also allows you to add paths to SDD
vpath devices that belong to active volume groups.

If you enter the addpaths command to an SDD vpath device that is in the
Open state, the paths that are added are automatically in the Open state.
With SDD levels earlier than 1.5.1.0, there is an exception when you enter
the addpaths command to add a new path to an SDD vpath device that has only
one configured path. In this case, the new path is not automatically in the
Open state, and you must change it to the Open state by closing and
reopening the SDD vpath device. This exception is removed for SDD 1.5.1.0
and later. That is, in SDD 1.5.1.0 and later, the new path will be
automatically opened after you add it to a opened SDD vpath device. You can
determine how many more hdisks can be added to the existing SDD vpath
devices by using the command datapath query device to find out how many
hdisks are already configured for each vpath. Ensure that the number of
hdisks from the existing configuration is below the recommended maximum
paths allowed according to Table 12 on page 34.

Notes: 1. If you configure more than 32 hdisks, running addpaths will not
add any paths to vpaths. 2. Before you run addpaths, you must run cfgmgr to
configure the new hdisks devices. Running cfgmgr alone does not add new
paths to SDD vpath devices."

The question is if the path can be dynamically added only on node handling reservation or on second as well.

 

[ogniemi]

the addpaths command did it perfectly having reserved disks on second node.