Methods for system backup

[john guardian]

I'm aware of the following backup methods:

- local tape drive

- remote tape drive

- to a remote ignite server

- using Disk Mirror and then splitting the mirror to preserve the original configuration

Are there any others, and if so, what are the ins and outs to them.

Thanks.

[Torsten.]

OS or data backups?

In case of OS "backups" you may consider DRD too.

[Bill Hassell]

- local tape drive

Always works well.

- remote tape drive

Only one corner case (fbackup) will work unless using a special backup package

- to a remote ignite server

The usual for large data centers.

- using Disk Mirror and then splitting the mirror to preserve the original configuration

Disk mirroring is only useful when a disk fails. It is useless if somone accidently writes over the boot disk.

..DRD is only available for more recent versions of HP-UX.

There are three boot disk problems: disk hardware failure where mirror disk protects vg00, someone (with root privileges) writes over the vg00 disk and smoke-and-rubble where vg00 must be reinstalled.

There is no substitute for Ignite. You could experiment with a dd copy but the destination disk must be installed in the same slot as the original in order to boot and run. If you have no tape drive and no disk mirror software, dd is about all there is.

Using NFS to backup is worthless to recover since the dead server can't be booted to enable networking.

DVDs are too small to hold a typical vg00 backup. A boot CD can be used to bring an Ignite menu up but you need either an ignite tape or a working ignite server to restore.

That takes care of vg00.

For the other volumes, fbackup is the tool of choice. While HP has decided to abandon this program, it is still the best (and fastest) tool for tape backup. The other backup tools are limited to files less than 9GB and single threaded limiting maximum tape speed.

[Dennis Handly]

>The other backup tools are limited to files less than 9 GB

pax (and Data Protector of course) don't have this limitation.

[john guardian]

Yes, I agree with the Ignite being the best approach. Unfortunately, the BEAN-Counting, middle managing, pencil pushers only see the dollars involved. Even when I explain to them that it's 20-30 min backup and the same to restore, they look at me like I just don't understand their point... This after I tell them that it's hours or days (depending on what is supported/configured along with the base OS) to do this manually. And even with all that, there's no guarantee that the end point of the restore is exactly what you started with, even if you are unconcerned with the loss of user data.

With disk mirroring, at least I can split the mirror to preserve the system.

DRD should be good as the systems that need to be preserved are mostly v3, with only a single v2 system. I believe the v2 system qualifies as well, based on the date of the disks originally used to build the system. It appears that DRD is available as a "free" download. In the past, I've used fbackup extensively and exclusively, and it produced very reliable results. But it's another one of those "old" UNIX utils that can get people by w/o the need to "purchase" anything (much), so no big surprise that HP abandoned it.

Thx.

[donna hofmeister]

sorry for jumping in to ask a (related) question...

i believe the man page for fbackup makes dire warnings about backing up to an nfs mount.  is that because of the challenge of restoring or is it something else?

[Bill Hassell]

Any backup over NFS is risky. The protocol is just too risky for backing up even a few gigabytes. It is also heavy on overhead so throughput is a major concern. Most of the modern drives like LTO3 and later are too fast for simple disks, and the network speed even at Gbit speed cannot keep up with the tape drive. This means massive repositioning (read: excess wear).  Here's a summary of the native data speeds for each tape format:

Type      MB/sec

LTO1 = 20

LTO2 = 40

LTO3 = 80

LTO4 = 120

LTO5 = 140

LTO6 = 160

A typical internal SCSI disk drive can keep data streaming from 20-80 MB/sec, SAS (JBOD) can push 100, but none of them can keep up with compressible data (which is often quoted at 2:1).

Certainly you can use NFS but it can be very quirky, and restoring can also be tricky. NFS is useless for a vg00 restore (there is no NFS on a dead system).

Using NFS negates most of the advantages of fbackup with up to 6 threads reading data at the same time.

As far as management goes, I'm sure they have not wasted any money on fire extinguishers and sprinklers, DR locations or even insurance policies. After all, they cost money and don't do anything...just like a backup.

Obviously your company has never experienced the financial disaster caused by a data center outage or even a disk array failure that takes down every client for 3 days. There are many businesses that no longer exist because of data that colud not be recovered.

[Torsten.]

By the way, I recently did an ignite backup of a rx2800 i4 using a LTO-6 in about 10 minutes, restored in about 15 minutes

;-)

[Dennis Handly]

>I believe the man page for fbackup makes dire warnings about backing up to a NFS mount.

I only see comments about backing up A NFS filesystem, not to one.