Backup with VXVM

[MAIQUES]

Hie,
How to backup the system disk which is encapsulated with VXVM ?
Tar all disk ?
For restore how to do ? How to do the boot part?
There is one disk mirrored. If I unclosed one of the disks is the other booting in each case ?
Thanks for your help.

[VK2COT · Accepted solution]

Hello,

You did not provide details of your setup.
Version of HP-UX, VxVM version, backup
softwqare (do you use Symantec NetBackup,
or HP Data Protector, or something else),
and so on...

For example, Symantec NetBackup offers
bare-metal recovery.

Otherwise, you can use something as simple
as tar(1) or fbackup(1) as long as you
know their limitations.

It all depends on your Business Continuity Plan. In other words, what is the financial
loss per hour if the server goes down?
That is the primary question I ask when I
design new servers. If I get the answer in
hundreds of thousands of dollars, then a
robust server is needed.

If you at luxury to recover the server in,
say, 24 hours, than you might not need an expensive DR solution.

Having software RAID1 (mirroring) is always a
good idea for critical data like operating
system (unless you can use RAID5 for boot
disks on SAN).

If you lose one disk, the system will automatically use the other one.

Many options exist to help you in
various disaster recovery scenarios.
Some of them listed here:

a) HP-UX Maintenance Mode Boot (MMB) is used
in the recovery from catastrophic
failures that have prevented the target machine from booting. If a mirrored root is
configured, then when booting in MMB mode, only one mirror is activated.

b) If a failed primary boot disk is under
VxVM control and is mirrored, follow these
steps to replace it:

1 Replace the failed boot disk.
Depending on the system hardware, this may
require you to shut down and power off the
system.

2 Boot the system from a mirror of the root
disk, and use the vxrootmir command to
initialize and mirror the volumes on the new
root disk:

/etc/vx/bin/vxrootmir -v -b new_root_disk_access_name

The -b option sets the newly mirrored disk as
the alternate boot disk in the NVRAM.

The -v option gives progress indications as
each volume is being mirrored.

c) If you have lost your system completely,
and re-installing on a new system with a new array, recreate the same environment you had
before the disaster.

The procedure assumes you save the following
results before the problem happens:

vxprint -mpvshr > file1
vxprint -ht > file2

1 Install the operating system

2 Install Volume Manager

3 Install Volume Manager license

4 Create rootdg via the vxinstall utility

5 Recreate other disk groups using the same
disk media names.

vxdg init diskgroup disk_name=c#t#d#

The disk_name is the dm name of the disk
when it was first added to the disk group.

6 Add the required disks to your disk group one at a time using the following command:

vxdg -g diskgroup_name adddisk disk_name2=c#t#d#

7 Recreate the volumes using backup files
you hopefully saved before the disaster:

vxmake -g diskgroup_name -d file1

8 Recreate the file systems. Example:

newfs /dev/vx/rdsk/disk_group_name/volname size

9 Mount the file system and restore data
from backup

Due to space constraints I will not go into other options like cloning and so on.

Regards,

VK2COT

[MAIQUES]

Thanks for your answer. It is very complete.
I have assigned points. Did you receive them.
The OS is HP unix 11.0
Volume Manager is 3.5
I have 2 disks 1 rootsystem and the other Rootmirror.
You say if one disk is failed the system boot automatically on the other.

NOw we have to put a Hardware patch.

The HP engineer want to disclose the mirror to keep it if the patch installation is going bad.
How to know on which disk the system had booted ?

Can we Unclosed the disk which is not used by the system to boot, to keep it if there any problem during patch installation ?

If the patch installation has going bad can we unclosed the disk (may be after shutdown) in use an closed in the disk kept off ?

Is there an action to valid the boot sector ?

Thank you for the complete description to make a new disk with a backup.

Sincerely.

[VK2COT]

Hello again,

I am a bit puzzled. HP-UX 11.00 does not
support VxVM 3.5:

11.00 JFS 3.1 Version 2 2GB 128GB
11.00 JFS 3.1 Version 3 1TB 1TB
11.00 JFS 3.3 Version 2 2GB 128GB
11.00 JFS 3.3 Version 3 1TB 1TB
11.00 JFS 3.3 Version 4 1TB 1TB
11i v1 JFS 3.3 Version 2 2GB 128GB
11i v1 JFS 3.3 Version 3 2TB 2TB
11i v1 JFS 3.3 Version 4 2TB 2TB
11i v1 JFS 3.5 Version 4 2TB 2TB
11i v2 JFS 3.5 Version 4 2TB 2TB
11i v2 JFS 3.5 Version 5 2TB 32TB
11i v2 JFS 4.1 Version 6 2TB 32TB
11i v3 JFS 4.1 Version 6 2TB 32TB
11i v2 JFS 5.0 Version 7 2TB 32TB

If you still used HP-UX 11.00, than
an urgent upgrade would be most advisable.
HP does not support 11.00 any longer.
Maybe you meant 11.11i (11v1)?

To break the mirror in VxVM 3.5, here is the
simple process (taken verbatim from the
HP documentation):

# daname= of mirrored root disk

# dmname=`vxprint -g rootdg -F %dmname -e sd_da_name~/$daname/|head -1`

# plxnames=`vxprint -g dg -F "%assoc" -e sd_dm_name==\"$dmname\"`

# vxplex -o rm dis $plxnames

# vxdg -g rootdg rmdisk $dmname

Once the system has been patched (or
repaired) and is up in normal mode, the root
volume can be remirrored using the command:

# vxassist -g rootdg mirror rootvol dm:rootdisk02

Cheers,

VK2COT

[MAIQUES]

Hello,
Thanks for your reply.
You are right.
The system is HP-UX 11.11
I'll go back to work on monday.
I'll use the VXVM commands that you have wrote in your reply.
If i have any problem I'll write to you.
The mirror disk is not good for boot.
I'll have to destroy it and rebuild a new.
Thank you.

Cheers

[chris huys_4]

Hi,

On HP-UX, bootdisks are not "encapsulated with vxvm". "boot vxvm encapsulation" is a technique that is used in a solaris env. (thus "un"ecapsulation on HP-UX also doesnt exist) In HP-UX, the vxvm integration, is a "real" integration.

To backup'd/restore the vxvm bootdisk use ignite. (the same as with lvm bootdisks).

> There is one disk mirrored. If I unclosed
> one of the disks is the other booting in
> each case ?
Not sure what you mean with "one disk mirrored". If you have a "2 disk" mirrored rootdg disksetup, then yes every disk should be bootable on its own.

NOTE: However Im not to sure you are that experienced with vxvm. I.e. I wouldnt do the commandline commands I saw in the previous responses, on a production system, without first trying to issue them, i.e. understanding them, on a testsystem.

Best Regards,
Chris