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Vgexport in hpux?

 
hpux_sun
Occasional Advisor

Vgexport in hpux?

please tellme how to take a map file in a Superdome environment, and is having two node clusters?

why do we use -s for vgexport ?

 

what is the content of a mapfile, is that contect is same for the other device when we do vgimport?

 

please help me...

 

 

2 REPLIES 2
James R. Ferguson
Acclaimed Contributor

Re: Vgexport in hpux?

Hi:

 

A 'vgexport' taken with '-s' adds the Volume Group ID (VGID) to the mapfile created when you use the '-m' option.

 

With the VGID, a 'vgimport' can discover physical devices that have a matching VGID by reading the LVM headers and thus import the volume group members without having to know and specify physical device paths.

 

Aside from the VGID, an LVM mapfile consists of the logical volume minor numbers and the *name* that you want to associate with the logical volume.  As such, if you didn't have a mapfile at all, and you specified the disk device paths via which to import a volume group, a "virtual" mapfile of default names would be used as if a real mapfile had specified:

 

1 lvol1

2 lvol2

3 lvol3

...

 

Have a look at the 'vgexport(1M)' manpages (as well as those for 'vgimport(1M))'.  There are some good examples therein with supporting details.

 

Regards!

 

...JRF...

donna hofmeister
Trusted Contributor

Re: Vgexport in hpux?

if you spend some time reading serviceguard documentation -- which i *highly* recommend <ahem> -- you'll find there is some disagreement about whether or not to use "-s" on vgexport/vgimport.

 

i think the handbook explains it best:

 

On systems using physical data replication products like BusinessCopy/XP,
ContinousAccess/XP, EMC SRDF or EMC Timefinder it may be impossible to
reliably identify the correct list of PVs using vgimport –s. You should specify the list
of PVs explicitely then. The newly introduced –f option for vgimport helps to specify
large PV lists on the command line (see man page). The –f option is available as of
HP-UX 11.00.

 

otherwise -- as james already explained -- the mapfile is a simple ascii file which lists the minor numbers and names of each lvol in the specified vg.

 

oh and since you're reading documentation, consulting the man page for vgexport would be useful too.