topic Re: script help please in Operating System - HP-UX

script help please

John Meissner — Tue, 28 Jan 2003 19:32:12 GMT

posted in the wrong place ... posting here to imporve visability
http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0x5f235bd3782dd711abdc0090277a778c,00.html

Re: script help please

John Poff — Tue, 28 Jan 2003 20:32:00 GMT

Hi John,

I've done something similar to what you are trying. I wrote a script 'build_vg_conf' that will write a simple configuration file which describes a volume group and the logical volumes in it. These config files are used by a second script, 'recreate_vg', which will create the volume groups and logical volumes. The 'recreate_vg' script can go search for your EMC disks, or you can pass it a list of PVs in a file. We've used this script a couple of times in disaster recovery drills and it seems to work. Feel free to take it and hack it up for your needs, or just copy the useful parts of it as needed. It does many of the same things you are trying to do in your script, such as finding a valid list of EMC disks, figuring out the next available minor number to use for creating VGs, etc.

Have fun!

JP

Re: script help please

John Poff — Tue, 28 Jan 2003 20:36:42 GMT

Here is the 'build_vg_conf' script. We usually put it in cron and run it once a day. The config files are small and we just leave them in our root home directory, and they get picked up for free by our Ignite backups.

Here is a sample config file:

PESIZE 4
TOTALPE 6471
LV /dev/vg_app/lvol1 /u01/app/oracle 2000
LV /dev/vg_app/lvol2 /u01/app/applmgr 4000

See, I figured out that all I really needed to recreate a volume group was the name, the PE size, and the number of PEs. The number of PVs in the old VG doesn't really matter because you might not have the same size PVs on the new system, and as long as the PE size is the same it doesn't really matter. The 'recreate_vg' script will look at this config file, figure out how big the VG needs to be in PEs, and start pvcreating PVs and throwing them into the new VG until it has enough PEs. Then it is a simple matter to create the LVs based on the LV entries in the config file.

Fun stuff!

JP

Re: script help please

John Poff — Tue, 28 Jan 2003 20:38:55 GMT

Oops. Here is the 'build_vg_conf' script. I forgot to attach it to the last post.

JP

Re: script help please

John Meissner — Tue, 28 Jan 2003 20:47:39 GMT

Great - Thanks for the script! I'll take a look and see if it works for my needs - at the very least I'll be able to redirect my approach from here.

Re: script help please

John Meissner — Thu, 30 Jan 2003 19:14:01 GMT

John - just out of curiousity - when you execute the 2nd script do you need to pass it any options? I ran it and came up with a few errors. and it doesn't look like it completed it's task. just checking. I definately will be using most of what you wrote to recover my vg's but so far the script doesn't work "as is". Any suggestions?

Re: script help please

John Poff — Thu, 30 Jan 2003 19:33:51 GMT

Hi John,

Which script gave you the errors, and what errors did you get? If it is the 'recreate_vg' script, I'm not surprised as I usually just run it [and refine it] while we are doing a disaster recovery drill, which means it only gets worked on when I am very sleep deprived and full of caffeine. [Not too far from my normal condition!].

JP

Re: script help please

John Meissner — Thu, 30 Jan 2003 19:53:41 GMT

John - yeah it was the recreate script. It had a few useage errors....

/usr/sbin/vgcreate -p 128 -s $VG
Usage: vgcreate
[-f]
[-A Autobackup]
[-x Extensibility]
[-e MaxPhysicalExtents]
etc.....

I can probably send you the entire file with all the output if you really want. I saved it to a file but it's too big to attach here.

I know what you mean about sleep deprived... our DR tests are the same way. Fortunately I work for Mars Inc (M&M candies) so I usually have a sugar rush going for me... plus one of our companies makes coffee so We bring a brewer with us to the test site. Still .... If I can get this working then it'll cut the build time down to almost nothing... and then we can go to out and have some fun :)
....and thanks for the quick response too.

Re: script help please

John Poff — Thu, 30 Jan 2003 20:04:14 GMT

Ok. The 'recreate_vg' script expects to find the *.config files for the volume groups that are created by the 'build_vg_conf' script. Did you run 'build_vg_conf' first to give it some .config files to work with?

JP

Re: script help please

John Poff — Thu, 30 Jan 2003 20:06:58 GMT

And you're welcome. My boss thinks I am busy working. Too busy to go help roll some new equipment from the other end of the building to the computer room. :)

JP

Re: script help please

John Meissner — Thu, 30 Jan 2003 20:50:29 GMT

Yes - the config files that the 1st script generated were in the same directory as the recreate script. in this case there were 2 files since the server I was creating had 2 vg's besides vg00.

Re: script help please

John Meissner — Thu, 30 Jan 2003 20:51:55 GMT

you get extra points for making your boss thing you're busy :)

Re: script help please

John Meissner — Thu, 30 Jan 2003 21:17:12 GMT

I'm attaching one of the config files that the script created

Re: script help please

John Poff — Thu, 30 Jan 2003 21:17:54 GMT

John,

Go ahead and post your output as an attachment. I'd like to take a look at it. Also, if you can post the two .config files I'd like to see them as well.

JP

Re: script help please

John Meissner — Thu, 30 Jan 2003 21:24:46 GMT

ok - the one config file i attached to my above post. I'll attach the 2nd config file here

Re: script help please

John Meissner — Thu, 30 Jan 2003 21:30:38 GMT

Re: script help please

John Poff — Thu, 30 Jan 2003 21:47:42 GMT

It looks like there were a couple of problems. In your first .config file the lvol8 and lvol15 logical volumes didn't get entries for the mount points. Are those LVs mounted currently? The 'build_vg_conf' script just takes the output from the 'mount' command to try to figure out the LVs and mount points.

Also, it looks like the 'recreate_vg' may have picked up a bogus .config file. The 'build_vg.config' file looks like it might be the culprit.

The vgcreate commands for the vg043bin and vg043data VGs choked with a 'file too large' error. I'm not sure what that is all about. Probably the author of the script should have put in more error checking!

JP

Re: script help please

John Poff — Thu, 30 Jan 2003 22:05:50 GMT

I poked around and I found a document that explains the 'file too large' error for the vgcreate:

http://www2.itrc.hp.com/service/cki/docDisplay.do?docLocale=en_US&docId=200000065011234

When I last used this script, we had a huge VG with just over a hundred PVs in it. The 'vgcreate' line in the 'recreate_vg' script is hard coded to set the Max PVs for 128. I think that is causing problems for vgcreate. Try lowering the '-p 128' option to something more reasonable, like '-p 32' and give it another go. You'll also need to get rid of the bogus .config file and make sure there are mountpoint entries in the vg043bin.config file.

Time for more caffeine!

JP

Re: script help please

John Meissner — Fri, 31 Jan 2003 12:21:40 GMT

Yes - I see the entry in the 1st config file that is messed up. I'll just try removing that or manually entering the correct information into the fields. I'll let you know how it goes.

as for the max extents... i'll take a look at that too. I know that some of our servers have terabytes of diskspace.... will the hardcoded 128 effect this?

Re: script help please

John Meissner — Fri, 31 Jan 2003 13:37:57 GMT