topic Re: Convert/expand virtual filesystem in Operating System - HP-UX

Convert/expand virtual filesystem

twodogmike — Fri, 30 Oct 2009 14:50:48 GMT

Have multiple issues that add up to a single problem:

Have rx3600 running HP UX 11i v2 set up as host to vpar set running as an Ignite server. The Ignite server has 72 Gb assigned for root use and 1.5 Tb for the Ignite archives directory. I have recently run out of space on archives and was assigned another 1.5 Tb of disk.

Now come the potential problems.

1. The system was installed by someone else. Filesystems - across the board are LVM. Obviously can't run 3Tb LVM filesystem on it.

2. I am familiar with vxvmconvert, but not on virtual server.

3. It is my understanding that the Ignite archive directory can be hard or difficult to expand.

I have read all the documentation I can find about virtual systems, VxVm and Ignite but they seem to ignore the fact that any other application exists.

Re: Convert/expand virtual filesystem

Michael Steele_2 — Fri, 30 Oct 2009 15:35:07 GMT

Hi

I've administered Ignite servers for many years now and I think you have some conceptual issues what ignite and root needs.

a) / root, is never more than maybe 500 MB, unless you're not using file systems like your supposed to. So paste in your /etc/fstab for a look see. Question: Are usr, opt, and var directories or file systems pointing to their own unique lvol? Or are they all under the / root lvol?

b) When you make an Ignite server you save two image copies and back the ignite server to tape once a month. Question: How many images are being saved per client? How many clients?

I.e, 70 servers each with two 4 GB images is only half a terra byte.

Re: Convert/expand virtual filesystem

Steven E. Protter — Fri, 30 Oct 2009 16:03:41 GMT

Shalom,

There are some practices that can avoid this.

When I get a 360 GB disk allocation here it actually consists of 10 36 GB LUN's presented to the system.

So if Storage wants to give me more disk, they just add a bunch of new LUNS to the EMC.

Your questions:

1. Wrong, you can go up to 128 TB possibly 256 TB LVM

2. Works the same, far as I know.

3. No problem at all expanding this, especially if new disk is added with the methodology I used above.

SEP

Re: Convert/expand virtual filesystem

Bill Costigan — Fri, 30 Oct 2009 16:26:41 GMT

The only difficulties I can think of when expanding the ignite archive are.

1. by default it is under /var. so if you don't have OnlineJFS and if you didn't create a new mounted/filesystem in that path (e.g. /var/opt/ignite/recovery) you might have problems unmounting /var to expand it.

2. Make_net_recovery and the ignite install both depend on NFS to access files in the archive. If you create new mounted subdirectories and in the process mess up the NFS exports or permissions, the ignite processes may fail.

Re: Convert/expand virtual filesystem

twodogmike — Fri, 30 Oct 2009 17:42:02 GMT

At the moment we have 197 clients, most with two images. I was aware of the concet with / and the archives seperation. /, /usr, /var, /tmp, etc are all seperately mounted filesystems.

I'm suprised that LVM can go that high. News to me. Last I heard it was 2 Tb. I'll move the disk over and try to add it to the existing filesystem. Thanks and shalom yourself.

As to the third comment, I think you're right. There probably will always be some risk in a process like this.

I'm going to leave this open just to see whether it's air or something else that hits the fan.

Re: Convert/expand virtual filesystem

Bill Costigan — Fri, 30 Oct 2009 18:09:15 GMT

New versions of LVM may allow more but the older versions only allowed 64K extents per Lvol. So if the extent size was 32MB x 65,000 that would yield 2,080,000 MB (just around 2TB

Re: Convert/expand virtual filesystem

Torsten. — Fri, 30 Oct 2009 18:11:27 GMT

For such large LVOLs you probably need to patch 11.23.

Re: Convert/expand virtual filesystem

Torsten. — Fri, 30 Oct 2009 18:23:13 GMT

From the well known LVM limits WP:

Size of a LV 11.23 with the
following or superseding patches:-
PHCO_36744, PHKL_36745,
PHCO_37939

Re: Convert/expand virtual filesystem

Bill Costigan — Fri, 30 Oct 2009 18:23:32 GMT

I checked the man page on lvextend

max extents / lvol = 65535
max size of extent = 256MB

256MB x 65535 = 16,777,216MB or just under 16TB

So the real qestion is what is the extent size on vg00? unless it is over 32MB the limit will not be greater than 2TB