VMS backup

[Gary H. Mims]

Environment: ES-47, ESA3000, MLT5026, VMS 7.32, and CACHE.
Currently we use a propriatary product from IDX Corporation called ZBACKUP for backup. The procedure freezes all databases, backs up the data,and then "thaws" the databases on backup completion. This is done when there are no users on the system. However, queries that are running are stopped during the backup downtime. Backup currently takes 2 hours. I need to reduce that time.

The only files that I am backing up are VMS files. I have lots of free disk space. One suggestion is to shadow the disk volumes. ZBACKUP knows how to split the shadow members for backup. That solution will immediately cut my free disk space. It will make increasing the volume size of the virtual disks on the fly more difficult. It will work, but I think there is a better solution.

Has anyone experienced a similar situation? I can afford "freeze" time, but I need to keep it to a minimum. If I have to use a backup product, what would you recommend? Veritas, Legato....?

Gary H. Mims
Texas Tech University Health Sciences Center
Lubbock, Texas

[Willem Grooters]

What type of database? If RdB or Oracle, I know there are facilities to do a on-line backup, not requiering halting any activity. I guess other RDBMS's will have a similar facility. If this is the case, I'd suggest to use that option; it's built-in into the RDBMS and works pretty well.

Shadwoing disks should be considered "good practice" anyway, and not just for backup.
So that option should be used regaurdless the database technology used, and not just for backup.

Breaking up a shadow set for backup however contains a danger: If the other disk breaks during backup, and acitivity continues, you will lose data that was entered/updated during backup. A better practice, I thnink, is to add a disk to the shadowset (it can contains 3 disks), synch the data and take it out when thet is finished - and back it up from there.
However, if you can use online-backup on your database, this isn't needed. Just for your RMS files.

having sais that, it's a wise decision to store plain RMS files on other disks than your real database files.. Just the RMS files need to be handeled using a (temprorary) third shadowset member.

Willem

[Peter Quodling]

If you have to use another backup product (Legato/Veritas) - actually I would go with Backup - One of my sites is under a corporate "Mandate" to use Legato - There is no such thing as gravity - the product sucks..

IN spite of what has been said about "Breaking shadow sets, the other thing to consider is going "bigger". Rather than have a two member shadow set, have a range of spare spindles that can be merged in to become the third volume in a three member shadow set, and then broken out and backed up - this doesn't compromise your integrity in the process.

In setting up backup, it's important to understand what you are backing up and restoring and why and how...

Is speed of restoration important? Is minimizing "backup window" important? Is data integrity important? Is speed of recovery important?

How much total storage do you have? How volatile is it (i.e. how much changes per day). Another consideration if it's relatively static, is switch to weekly full and daily incrementals. If you use VMS backup, there is a mproduct called saveset manager which allows consolidation of full and incremental on tape savesets to give a complete and current restoration kit.

Also, what tape infrastructure do you have. MSL (Not MTL 5026) - depending on the above profiles, you may want to consider moving to higher capacity drives (like LTO's or super DLT's) or higher performance (like STK 9940's) drives.

The other consideration is minimizing the "requirement for backup" particular if a lot of the data is dated or static (and you are in a Health sciences centre so lots of archival information... ) There are a number of VMS HSM (Hierarchical Storage Management) products around - by "parking" infrequently used data to tape, which easy fast and automatic retrieval, one can gain significant performance boosts.

q

[Jan van den Ende]

Gary,

Our solution:

- 3-member Shadowsets.
- Backup procedure starts with quiescing Databases.
- Split off 1 member of each shadowset.
- Re-activate Databases.
- convert/share permanent-open files on split-off member(s)
- Backup split-off memebers.
- Mount 3rd members in shadowsets.

Re: It will make increasing the volume size of the virtual disks on the fly more difficult.

How so?
How is that any more difficult than for single disks?
You need to INIT the disk once anyhow, shadowing or not. (and since recently you can specify /LIMIT).
And if you for a shadow set from that, you are home.

And the only Backup products that I can recommend, is native VMS BACKUP, and any product that implements it directly. That disqualifies Legato as well as Veritas.

hth.

Proost.

Have one on me.

jpe

[Robert Atkinson]

Gary - what sort of disk controllers are you using?

You may be able to do a Clone or Snap (instant) backup from there.

Rob.

[Wim Van den Wyngaert]

Be careful when implementing a 3 member shadow set that is split for a backup.
You might get performance problems ...

http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=707709

Wim

[Jim Geier_1]

I am an experienced IDX system manager, having managed IDX environments on OpenVMS systems for about 15 years now.

ZBACKUP is a set of DCL command procedures that ultimately use the OpenVMS Backup Utility to perform the actual backup of the disks to tape.

If you use something other than ZBACKUP for your backups, then you can no longer hold IDX accountable for your backups -- you will have to support your backups yourself. This becomes an important consideration, because while you may know how to write a simple set of DCL scripts to perform the database freeze and backup operations, is that the best solution for your company should you leave? If you are not there, your company may turn to IDX for support should the backups fail, and if you are not running ZBACKUP, your company might be left without backup support. And backups are an important part of what an IS department provides for a company.

Having said that, the reason for the lengthy database freeze time is probably because you do not have shadowed disks. The databases must be in a read-only mode for the duration of your backup operation when there are no shadowed disks. If you really need shorter freeze times, then shadowing your disks is a good solution -- the duration of the database freeze with shadowed disks is the amount of time to separate the shadow sets. But then you face shadow set copies after each disk's backup is complete. I do not know whether ZBACKUP has been retrofitted to use the shadow mini-copy, and I doubt it, because ZBACKUP is a "jack of all trades, master of none" type of general solution.

If you move to a Veritas or Legato type of solution, and you do not have shadowed disks, the database freeze time will not be reduced -- unless the databases are in a readonly mode while the backup operation is in progress, the restored databases will not with with DSM, ISM, or Cache (whichever is in use at your site).

My recommendation is to work with the IDX support people to ensure that the parameters in the ZBACKUP parameter file are optimal with a high block size for the backup savesets, a large group value, and making sure that compression is enabled if your tape device supports it.

If you can afford it, shadowing the disks is a good idea for data protection generally -- that data you are backing up every night is one of your company's key assets, and really deserves being protected by redundant disks all the time. It may be that you have to add some disks to provide for shadowing and provide for adequate disk space for normal database growth. Disks are relatively cheap today, so make sure you have redundancy for your disks the best interests of your company.

This is a good forum to learn and get advice about general OpenVMS topics. There are several threads here discussing BACKUP and the pros and cons of BACKUP qualifier values. You might also subscribe to the IDX System Manager's e-mail list to get insight from other IDX system managers about IDX-specific system management issues. I use both forums routinely.

[Jan van den Ende]

Re Jim


I do not know whether ZBACKUP has been retrofitted to use the shadow mini-copy, and I doubt it,


That _IS_ one beautiful aspect of mini-copy:
it is COMPLETELY automatic, once your disks are set up for it!
(And provided you do NOT overrule shadowmembership. And your out-of-set time (or rather the activity of the remaining active set) is not too long, your mutation log file must be able to hold all mutations since the member dismount)
So yes, for our disk that hold the SYSUAF, RIGHTSLIST, QUEUE control files etc, which we CONVERT/SHARE, that means a full copy, but all athers are happily doing minicopy!

hth

Proost.

Have one on me.

jpe

[Robert Davidson_1]

Zbackup has been updated to use /minicopy and it does speed up the disk copy and re-mounting of the disks after backup.

We use 3 member shadow sets and drop one set for the backup. The total freeze time is about 15 minutes. We stop the incoming data interfaces, freeze the IDX system, wait for 5 minutes, drop member from each shadow set, unfreeze the IDX system and start the interfaces.

The actual backups take about 2 hours. This is with 12 DSA's across 4 tape drives. The individual DSA's get mounted as soon as their backup operation finishes.

Bob Davidson
Loyola University Physician Foundation
Maywood, Il

[Gary H. Mims]

I appreciate everyone's answers and they have been helpful. I know the IDX drill about using backups other than ZBACKUP or Legato (since they are a partner). We used SLS for a number of years. Restoring a file was very seldom done--two files in 10 years? We were able to restore the files....

Volume shadowing is the easiest solution. But, if you look at what the EVA3000 can do, it seems like taking a step backward. Why not also add software caching at the same time while moving backwards?

It seems to me that this could be done very easily with Snapshot/Snapclone. I was hoping that maybe someone actually had experience with this or had developed a script to model this after.

Gary H. Mims

[Robert Atkinson]

Gary, we do use SNAP on our HSG80's and TapeSys to backup the drives.

I've attached the relevant scripts.

Rob.

[Robert Atkinson]

Plus...

[Robert Atkinson]

And...

[Gary H. Mims]

Thanks Robert, I will review the scripts

Gary H. Mims