VxVM

[PVR]

I have seen that VxVm won't come up with out rootdg.

1. What all are the contecnts of rootdg?

(I believe all configuration information for aare stored in the private region of disks in the disk group.)

2. is it possible to import a dg into two different machine at the same time under any condition?? If yes..pls explain the scenario.

Thanks in advance
PVR

[Ralph Haefner]

1. rootdg is the required "root" diskgroup that is created when you do vxinstall. On machines where Veritas controls your boot disk, it will contain stuff like /, swap, /var, /opt, and other system filesystems.

2. No. You can export a diskgroup from one machine and import it to another. But you can't have it simultaneously on two different machines.

Note: I may be technically wrong about this as you may be able to force it to import on a second somehow. Veritas certainly gives error or warning messages if you try, but you may be able to override it somehow. But even if that is possible I certainly wouldn't do it since you have extremely big risk of data corruption. If you really do want to do this, check the man pages on vxdg import and see if the force flag might let you force an import without a previous export. If there is a way to do it I would think it involves that kind of procedure.

[PVR]

I have rootVg (VG00) in my HP Box and using VxVm to manage other disks. In that case what is the importance of rootdg?

[James A. Donovan]

You can indeed have the same disk group imported onto two (or more) machines at the same time. The caveat here is that this should really only be done when you are running an application like Oracle Parallel Server on that disk group. When you have the same disks mounted on multiple machines in read/write mode, you MUST have an application that understands how to coordinate writes to the disk, otherwise you will end up trashing your data.

[PVR]

yes..oracle parallel server edition is running in the productions server. While taking backup, mirror copy of disk array splits and BKUP server will import all DGs and take backup. At the same time I can do read /write operation in the productions erver. But....

How Vxvm will manage this scenario?? I think hostid also plays an important role int he import and export operation.

can I get any documents related to this??

Awaiting more info abt rootdg....

thanks