Disk Arrays
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Business Copy and Veritas Volume Mgr

Paul McCleary
Honored Contributor

Business Copy and Veritas Volume Mgr

Here's one that'll make u scratch your heads me thinks!

Using business copy we have a pvol and svol (primary and secondary volume) when the pair are split we need to mount the svol onto the SAME host as the pvol for development work.

Say we have vg01 with 2 disks, 1 the pvol the 2nd the svol. With LVM after the pair is split:

1) mkdir/mknod another volume group vg02
2) run vgchgid on the disk
3) vgimport the svol using /dev/dsk/c?t?d?
4) avtivate the vg
5) mount the lvols and fsck the filesystems

This works fine.

With volume manager once the pair is split:

1)Tried using:
vxdg -tC -n diskgroup-temp import diskgroup

There are 2 key problems with volume manager the first is that no disk device argument can be given to the import command above and there is no vgchgid equivalent to change the unique disk group number in the private area (at least that I'm aware of).

Does anybody have any ideas how we can get round this?

Thanks, Paul
John Tyler

Re: Business Copy and Veritas Volume Mgr

You can try use the snapshot option of vxassist.

1. Create a snapshot mirror for a volume with this command:

vxassist snapstart volume_name

Once the snapshot mirror is synchronized, it continues being updated until it is detached. If the snapshot procedure is interrupted, the snapshot mirror is automatically removed when the volume is started.

2. When the snapstart step is complete and the mirror is in a SNAPDONE state, choose a convenient time to complete the snapshot task. Inform users of the upcoming snapshot and ask them to save files and refrain from using the system briefly during that time.

3. Create a snapshot volume that reflects the original volume with this command:

vxassist snapshot volume_name temp_volume_name

This breaks the snapshot mirror and attaches it to the new temp_volume_name.

4. Use fsck (or some utility appropriate for the application running on the volume) to clean the temporary volume's contents. For example, use this command:

fsck -y /dev/vx/rdsk/temp_volume_name

At this point, there is a new volume and filesystem which may be mounted on a temporary mount point.

5. Unmount the FS and remove the new volume if you try to take another snapshot and use the same temp_vol.

vxedit -rf rm temp_volume_name

Paul McCleary
Honored Contributor

Re: Business Copy and Veritas Volume Mgr

Hi Ven,

Thanks for your reply. But Business Copy represents a significant software investment and ensures that all the mirroring is handled at the array end regardless of what hosts are attaching to it and their o/s.

The issue I have is with veritas volume manager 3.11 not allowing me to mount an identical bit4bit copy of the original volume onto the same server, due to the vol mgr identification data being the same in the private regions of the original and the copy. LVM allows you to change this with vgchgid and also to import a specific target disk as oppposed to a disk group.

Thanks anyway, Paul
Keith Clark
Valued Contributor

Re: Business Copy and Veritas Volume Mgr

Looking at the date on this I am going to assume that you have found the solution by now. I have never used BC together with Bcopy, but I have had experience trying to repair a vxvm private area on a Solaris box. I imagine it would work the same on hpux. You should be able to find a binary called vxprivutil in the /etc/vx/diag.d directory. This will let you scan, dump and edit the private region attributes. I do not know what the exact syntax would be, but you should be able to test and figure it out quite easily.

Try vxprivutil -help to get the options and do a quick search on google for "vxprivutil" to find a Sun blueprint that may be helpful.

I am very curious to find out your vxvm experiences with the XP.

Paul McCleary
Honored Contributor

Re: Business Copy and Veritas Volume Mgr

We never got it to work. Had to end up using a separate Solaris box to achieve it.

Cheers Anyway, Paul
Joaquin Gil de Vergara
Respected Contributor

Re: Business Copy and Veritas Volume Mgr

I think that tyhre isn't equivalence in VxVM with the vgchgid command...

Almost in this guide it not appear

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