LVM question

[Lacrosse]

I am working on a DR plan and would like to know if my DR site has various disk arrays i.e HP EMC and IBM in the event of invoking a DR event I want to start restoring data at the DR site over temp servers with a copy of the production LVM table which will build my existing LUN's then when my drop ship DR servers show up the data will be restored and I should just be able to hook up the new servers and go....am I missing anything?

[Uday_S_Ankolekar]

If you have similar set of hardware at DR site then probably make_recovery_tape(ignite) will be more helpful.
This ignite tape will restore your lvm,kernel,filesystem etc., information as at Basically the entire vg00 (depend on how you create ignite tape) only thing then you need to take care is restore production data

-USA..

[Lacrosse]

Thanks I was palnning on Igniting the DR server thus creating VG00 to save time I wanted to build the database LUN's prior to the actual DR server showing up and restore the data on a smaller temp server

[Patrick Wallek]

You can build your LUNs, VGs and LVs on one server and start restoring the data. Then when your DR systems arrive you can vgexport the VGs from the temporary server and vgimport them onto the DR servers. You will then have all your data available.

[Rick Garland]

Depending on who is your DR site vendor and what type of DR contract you have with them, they may do all of the array building for you.

At the HP DR sites, let them know what you have and the specs and they will do the config. All that remains for you is to ignite the server and start restoring your data.

[Lacrosse]

I guess my thought was I could send a backup of the LVM tab and send to the DR site where you can import it onto a temp server and build your LVM's and start resoring data when the server shows up the LVM structure should match the file system structure the server is loking for .....your thoughts.....any probs??

[Patrick Wallek]

That in all likelihood won't work.

You're /etc/lvmtab file just tells the OS which disks are part of which VG. You've then got your /dev/vg* directories which tells the OS which LVs are on which VGs. Your disk device files will more than likely be different on your DR units anyway. If they did happen to match up, I would be really impressed.

The biggest thing you won't have, though, is the VGRA and LVRA that is on each and every disk/LUN. Those are what hold that majority of your VG and LV information.

Your best bet is to just have a script that you configure at the DR site and it will then build all of your VGs and LVs for you.

[Lacrosse]

what if we look at it in reverse where the LVM structures are in place how hard would it be to have a drop ship server recognize those logical volumes

[Patrick Wallek · Accepted solution]

If you have previously created all of your VGs and LVs on your DR SAN array, then it would be a fairly simple matter to vgimport those onto your DR servers when they arrive.

The easiest way to do it would be to create all of your VGs and LVs and then vgexport them with the -s option and create your map files (vgexport -m vg??.map -p -v -s vg??).

Then when your DR server(s) arrive, you copy the appropriate map files to those servers, create the /dev/vg?? structure and group file(s) and then vgimport those VGs.

# mkdir /dev/vg??
# mknod /dev/vg??/group c 64 0x0?0000
# vgimport -m vg??.map -v -s vg??

Just do that for all VGs on each server and you're then ready to go.

[Anthony Lennan]

Hi Hookermhorns,

If you're looking at it in reverse then I think it's exactly as Patrick mentioned before. You can setup your tempory server with the disk attached you can restore all of your non root volume groups to the external disk.

Once the drop ship arrives you should then install a copy of your OS on it with a make_recovery tape.

Then when you're ready you can do a vgexport on the temporary server and export all of the volume groups on the external disk. You should create a map file when you do this and then copy it across to the dropship server. You can then detacth from the temp server and attach it to the DR server. Then run a vgimport with your map file and all of the volume groups should then be seen.

Cheers,
Anthony

[Lacrosse]

Awesome thanks for all the help