Tape recovery using make_recovery or make_tape_recovery

[Timmy Sin]

I am still wondering on which command I should use after reviewing some documentation and information from the forum. The commands are so similar. How would HP develop such similar commands under the same tool? What are the positions of the two commands in recovery? Is the make_tape_recovery command going to replace the make_recovery command and the latter one is only kept for compatibility purpose?
Some more questions, how can I test the commands in a healthy system? Will it work to create the recovery tape and use the tape to boot the healthy system? I have concern on the feature that logical volume physical extent allocation would not be preserved during recovery.

Grateful if any advice would be provided.

[Patrick Wallek]

The make_tape_recovery command is the preferred command for making an Ignite/UX tape. This command will eventually replace the make_recovery command. I believe the man page for make_recovery states something to the effect that make_recovery , when executed, will call make_tape_recovery in a future release.

You should start getting familiar with make_tape_recovery now.

You can create a make_tape_recovery tape on a running system at any time. Actually creating the tape will not change anything on your system. The make_tape_recovery command I use to create a tape is:
/opt/ignite/bin/make_tape_recovery -a /dev/rmt/0mn -I -v -x inc_entire=vg00

The meaning of the options are:

-a /dev/rmt/0mn - device file to write to. You should always use the no-rewind device file (/dev/rmt/?mn).

-I - When you boot from the tape it will automatically come up in Interactive mode so you can make any changes you want to make.

-v - verbose output

-x inc_entire=vg00 - include your entire vg00 boot volume group.

Once the tape is created, you can boot your system from it and as long as you made the tape with the -I option it will come up to the install menu. You can then go through the menu and do everything EXCEPT actually tell it to restore the system.

I am confused about your last statement concerning LV PE allocation being preserved. Can you elaborate on your concerns?

If you don't make any changes, your vg00 LVs will be laid out exactly as they were when you made the tape. If you had other VGs on the system, and you restored to the same system, your other VGs will still be available.

[Bill Hassell]

make_recvoery was the original design of Ignite/UX for vg00 backup. Later, the make_net_recovery code was written but significant changes were made for better performance and handling of complex configurations. make_tape_recovery is based on the new code in make_tape_recovery and is the preferred command. The command line options are slightly different between the two programs although -Av works the same in both. I always recommend -v so I see something happening.

[Eileen Millen]

It is best to use the latest version of Ignite which is 3.3. There are a lot of improvements.
make_tape_recovery -AvI -d /dev/rmt/0mn

To check a tape:
mt -t /dev/rmt/0m rew
mt -t /dev/rmt/0mn fsf - forward skip one
get table of contents
pax -vf /dev/rmt/0mn

You can also get files back from the tape with tar as a test.
you would do the 1st 2 lines again to forward past the LIF area
tar -xvf /dev/rmt/0mn pathname

Eileen

[Mark Childress]

Hi Tim,
In its current state (Ignite 3.3) make_tape_recovery can not replace make_recovery in its entirety. This is because the -C option is not available on make_tape_recovery, this allows you to create a makerec.last file which can be used with the check_recovery feature. The check_recovery feature allows you to compare the current state of vg00 against the previous make_recovery tape contents. I use this to determine whether a new make_recovery tape is needed.

[Patrick Wallek]

I was at an Ignite/UX presentation at one point a few months ago and I heard that HP will probably do away with the check_recovery command at some future date. Probably at the same time that the make_recovery command goes away.

The logic for this was, essentially, that if you think you need to create a new make_(tape_)recovery tape, you probably do. I don't know if this is still HPs official line or not...

The -C option also greatly slows down the tape creation process.

I personally have a cron job and create a recovery tape once a week. With the scheduled job, the -C option is kind of pointless.

[Sanjay_6]

Hi Timmy,

Have a look at this thread.

http://us-support2.external.hp.com/cki/bin/doc.pl/sid=9476a6df06f6a3e8b0/screen=ckiDisplayDocument?docId=200000055193691

Hope this helps

Thanks

[Timmy Sin]

Hey folks,

Thanks you all for the precious information provided.

Patrick, let me elaborate my concern as follows. I have two 4GB disks and one 4GB RAID-1 pair in my VG00. The LVs on the disks are mirrorred using LVM. After the system is up and running, I want to create a dedicated dump. As the first 2GB space of the disks had been occupied, I have to create the dump on the RAID-1 pair. I am wondering how make_recovery would handle this. Would it move my dedicated dump to the disks instead of the RAID-1 pair? The statement below is extracted from the MAN page of make_recovery "An example effect of this is that swap/dump volumes will reside on the root disk ahead of some other volumes even though that may not have been the original layout."
Hope that it is clear enough.

[Patrick Wallek · Accepted solution]

OK, I think I understand your question better now.

When you restore from an Ignite/UX tape, your LVs will not be recreated on exactly the same disks as they reside on now. Keep in mind that although you have disks that are mirrored in your VG00 now, those will not be remirrored automatically. You will have to remirror them by hand.

If you do not want your dump area to be recreated when you reinstall a system from the Ignite tape, you can modify the LV setup through the menu when you boot from tape interactively.

I hope this answers your question.