can this be done with root mirror ...

[K.C. Chan]

All,
I have mirror root volume group on an hp-ux, now if I pull off the primary root drive (swap included) while the server is runing, will the mirror root drive transparently take over (the server would continue running)? Thanks.

[steven Burgess_2]

Hi

As long as your disks are hotswapable you will be ok.

Follow these steps:

1. Restore the LVM config/headers onto the replaced disk with
vgfgrestore.

2. Reactivate the volume group.

3. Notify the volume group about the the replaced drive by
running vgchange:

vgchange -a y /dev/vg00

Note: This step will cause LVM to know that the disk is available
again and will do a resync.

4. Synchronize the PEs that are most likely marked as stale:

vgsync /dev/vg00

Note: This process might take a while depending on the vg size
and data size.


Here is a doc about common misconceptions with regard to mirrored root disks

HTH

Steve

[Fragon]

Of course you can!
Pulling off your disk is just the same as the disk fail!

-ux

[Norman_21]

I really doubt that you can pull off the primary root drive while the system is running and when the disk is claimed. You might crash the system.The mirroring does provide extra copies of essential root filesystem data but does not necessarily provide an alternate boot disk and does not provide "failover".
You'll need to make sure that both disks are boot disks, use the lvlnboot -v command to find out!

Hope this help.

[steven Burgess_2]

Hi

Here is the docId.

http://www5.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000062683870

HTH

Steve

[A. Clay Stephenson]

Remember, mirrors are not mirrored at the disk level but rather at the logical volume level. As long as all LVOL's on the primary boot -- including swap -- then the system will keep running. Of course, it's only safe to yank a drive from a running machine if the drive is hot-pluggable.

I have not shutdown a machine to replace a failed or flaky drive in over 5 years --- I just yank 'em and do the LVM stuff to replace the failed/flaky drive --- all 'on the fly'.

[K.C. Chan]

Yes, the mirror disk is created with the -B options. Yes, I did take addition steps to put the LIF and Diag tools onto it. Yes, the disk are hotswapable. I am not at work right now but I will post the output of lvlnboot -v, I want to confirmed if my configs are right. I have not work with hp-ux quite somtimes now. Thanks for all your input.

[Fragon]

I made the replacement about 20 days ago and no problem.
I have all LV(include lvol2) mirrored.
Maybe a lvlnboot -v will help more for us to decide!

-ux