vgchange -c y

[D.Blond]

Hello,
I have two servers in a MCSG cluster.
after one year, MCSG is deactived the vg's are actived with vgchange -c n and vgchange -a y.
Now, i want reactive the cluster.
Must i do a vgchange -c y before or not....
Thank's

[Matti_Kurkela · Accepted solution]

If a VG is clustered (i.e. the disks have been presented to two or more hosts) then yes, "vgchange -c y" is necessary.

Otherwise, the system will not enforce proper locking and there is a possibility of accidentally activating the VG and mounting the disk on more than one server simultaneously. This will cause data corruption, because of disk caching.

When "vgchange -c y" is in effect on a VG, that VG cannot be activated with the usual "vgchange -a y": you must use "vgchange -a e" instead. And "vgchange -a e" works only when the server is running Serviceguard and a member of the cluster (the server status is "up" in "cmviewcl" output), AND no other node in the cluster has the same VG active.

If the VG's disks are presented to one host only, then "vgchange -c y" is not necessary for that VG, even if the system is running Serviceguard. Normally, vg00 should *never* be in "vgchange -c y" mode.

MK

[Sajjad Sahir]

vgchange -a n (volume group active no)
vgchange -a y (volume group active yes)
vgchange -s y (volume group sharing yes)
vgchange -s n(volume group sharing no)
vgchange -c y(clustering yes)

This way u can easily remember


from u above postings u activated only volume group u have to activate cluster also
by using vgchange -c y

thanks and regards

Sajjad sahir

[D.Blond]

thank's