How to make a mirror on an existing volume group..

[M Dijsselbloem]

Hi,

Currently I have a volume group on one machine, but I want to make a mirror on an other machine for it.

On machine A I???ve made a volume group calles /vgtest which is made over 2 luns.
Vgdisplay ???v /dev/vgtest shows te following:

/dev/dsk/c43t2d1
/dev/dsk/c33t2d1 Alternate Link

/dev/dsk/c33t2d2
/dev/dsk/c43t2d2 Alternate Link

On machine B I???ve made 1 lun with the following device files:
/dev/rdsk/c59t4d1
/dev/rdsk/c60t4d1 Alternate Link

I???ve added the following lines in the /etc/lvmpvg file:
VG /dev/vgtest
PVG room1
/dev/dsk/c43t2d1
/dev/dsk/ c33t2d2
PVG room2
/dev/dsk/ c59t4d1

vgextend ???g room1 /dev/vgtest /dev/dsk/c59t4d1

lvchange ???s g /dev/vgtest/lvol1

lvextend ???m 1 /dev/vgtest/lvol1 /dev/dsk/ c59t4d1

Is this te right way to do this?? This is quite new for me.

Thanx in advance,

Mark

[James R. Ferguson]

Hi Mark:

If my "machine" you mean two physically distinct servers, then you cannot do this. MirrorDisk/UX mirrors logical volumes of a volume group within a server.

Regards!

...JRF...

[S.K. Chan]

In addition you may want to get a better understanding of LVM by reading some of the docs which can be found in ..
http://www.docs.hp.com
http://www.docs.hp.com/cgi-bin/onlinedocs.py?mpn=B2355-90742&service=hpux&path=00/00/1&title=Managing%20Systems%20and%20Workgroups%3A%20A%20Guide%20for%20HP-UX%20System%20Administrators
Also check out chap 16 of the Software Recovery Handbook
http://us-support3.external.hp.com/iv/data/documents/DE_SW_UX_swrec_EN_01_E/Introduction.pdf

[Martin Johnson]

What you are looking for is Remote Mirroring. Veritas offers products that do Remote Mirroring and other High Availability options:

http://veritas.com/products/category/ProductCategory.jhtml?categoryId=2018&baseId=2016

HTH
Marty

[Ian Dennison_1]

Another possibility to achieve what you want (remote copy of data on another machine) is to use the extended features of the Application that this data belongs to.

Is it a database? Many databases have replication functionality, oracles is especially good.

Is the data dynamic enough to justify the expense and admin overhead in duplicating it? If it is read only, or is only required to be within 1 day of current data, you can schedule a nightly backup and restore.

Hope this helps, share and enjoy! Ian

[Kevin Wright]

You can't mirror a VG to a disk that the system isn't connected to.

dev/dsk/c59t4d1 needs to be a device file known to machine A.

[twang]

I think you cannot directly mirror a disk to another machine using MirrorDisk/UX.
If the machine A and B are using disk space from a "concentrated disks", such as SAN, then you may think about mirroring on SAN side.