Use of vgchange -s_?

[Sebastian Perez]

Hello Everyone, Could you explain me in wich case I can and I must use vgchange -s. What does the option -s means_?
thnx.

[Pete Randall · Accepted solution]

Sebastian,

Does this quote from the man page help any or have you already seen it:

". . . mirror synchronization refreshes stale mirror copies by copying
data from a nonstale copy. If the -s option is specified on the
command line, mirror synchronization does not occur. However, for
those logical volumes that have Mirror Write Cache turned off, mirror
synchronization is done independently of whether the -s option appear on the command line."


Pete

[G. Vrijhoeven]

Hi S.

check man vgchange:

-s Disable the synchronization of stale physical
extents within the volume group specified by
vg_name. This option is only effective when
used with the -a y or -a e option.

So you can only use it if you activate the volumegroup exclusive ( cluster) or on one node only.
Stale physical extend are not synced. this means if one disk is corrupt the corrupt extends are not copied to the mirror disk.

Gideon

[Sridhar Bhaskarla]

Hi Sebastian,

When you do a vgchange -a y on a volume group that has mirror logical volumes, it will try to sync the mirrors. -s option will disable it. You can later manually sync the mirrors by doing a vgsync.

-Sri

[Sebastian Perez]

Thank you all of you for your explanation, it is usefull. Done.

[Dwyane Everts_1]

Sebastian,

The above answer the question "What?" Hopefully, I can explain where you would use it.
We use it in 2 instances...(1) ServiceGuard, and (2) Oracle RAC. This option is used in conjunction with -S. You first have to make the volumes Shareable (-S), then make sure you don't sync up stale volume (-s). That is basics behind it.
If you would like a more detailed definition, check out the manuals for installing ServiceGuard. They is much more info there.

D