IT Employment

General discussion


Determine your tape backup strategy

By debate ·
Are tape backups part of your organization's disaster recovery plan? How does your organization perform tape backups? Do you store backups off-site? Share your comments about determining your tape backup strategy, as discussed in the Jan. 6 Disaster Recovery e-newsletter.

If you haven't subscribed to our free Disaster Recovery e-newsletter, sign up today!

This conversation is currently closed to new comments.

Thread display: Collapse - | Expand +

All Comments

Collapse -

This is a good start

by stuck_in In reply to Determine your tape backu ...

We do full backups everyday because we have the time and we can afford it. Tapes are stored offsite and if need be I can go back and restore from a year ago. To not have a backup plan and test it is to live dangerously. It is boring but it can save jobs!

Collapse -

Consider Recovery Time Objective

by DRPlanner2 In reply to This is a good start

When determining whether or how often to do a full backup vs incrementals or differentials, take your recovery time objective into consideration. If you need to be back up and running within 4 hours but your recovery of a full backup plus 4 or more incrementals takes at least 8 hours, then you may have to figure out how to fit a full backup into your daily schedule.

Collapse -

This is rather simplistic

by draco vulgaris In reply to Determine your tape backu ...

The full, differential, and incremental backups are all done with the assumption that the system is quiescent! Backing up a file that is actually being written does not necessarily produce a usable backup. The backup is sequential but the file can, at least potentially, be accessed randomly. Suppose the application writes to a part of a file already backed up to tape and then to a part that has not yet been backed up. Restore this backup and what have you got? A file that is potentially inconsistent. If the two write operations were part of the same transaction, what you've got is garbage. Maybe you can salvage it or maybe not.

If it's all you have, you live with it and try to make your backups when nothing else is happening. If your system runs 24x7x365 you need to find something better.

Collapse -

This is rather simplistic

by swnz In reply to This is rather simplistic

Very true.

A way to help get around this problem, is to ensure that you have sufficent storage to create an off-line copy of the data you wish to back up. The backup tape jobs would then run an overnight backup on this data.

Of course, you require the funds to purchase a second storage array, and this only reduces the chance of an inconsistent backup being made.

We personally don't have a choice.... 2.5TB of data doesn't back up to a tape drive array very quickly at all!

Collapse -

Export Databases

by Fridolyn In reply to This is rather simplistic

Well consistency is mostly an issue with databases, we solve this by exporting them whit Oracle to a data file before we run the backup.
On the most important database we run the Oracle RMAN to make backups to a disk file and save then this files to tapes whit the ordinary backup process.

There are other ways, like file system snap shots, (the OS does not write changes to the filesystem but to an intermediate storage), or you can close all applications shortly, split your mirrors, open the applications again, and run then the backup against the offline mirror, after the backup you have to resync your mirror.

This all depends on what you need, I hope my bank does it even better ;-)

Collapse -

If you have the resources -

by cpr In reply to Determine your tape backu ...

If you have the computer resources and manpower, you could create duplicate sets of backup tapes. This allows one set to be stored off-site, and another to be kept on-site (for quicker restore situations).

The original backup set could be created overnight, and the second backup set could be created during the day on a less powerful computer system using the original backups as the input source.

We also 'roll-up' our data. If we create daily data files, we backup them up daily, but when we consolidate them into a weekly file, the weekly file is backed-up and the daily backups become free. This same technique can be used to roll-up data for monthly and yearly purposes. This actually saves us quite a few tapes during the year. We use 8 daily tapes, 5 weekly tapes, 13 monthly tapes, and 10 yearly tapes. Granted the files on the tapes become larger, but the frequecy of access is much less for yearly tapes, than for daily/weekly tapes.

My 2 cents.

Collapse -

Another Way To Backup

by john.a In reply to Determine your tape backu ...

We use to do tapes, but found a better way 2 years ago. Online Backups. We use an online provider out of Idaho for about $18/month. If anyone is insterested in the technology, check out We backup QuickBooks and some Docs online and use the tape backup only once a month - for full backups.

Collapse -

just another thought

by jim In reply to Another Way To Backup

With most companies that have the resources tape is fine. But Tape is cost prohibitive for my clients that fit the medium to small business'.

With our approach, cost is always on the forefront and with hard disks being So inexpensive and so large in capacity we use a two prong approach.

One is a product called powerquest V2i which costs only 695.00 USD which is 1/2 the cost of a DLT plus 14 tapes. We use our SAN as the backup farm for our clients. Even PC's with a 4 200 gig SATA drives can also be used as the backup.

We have gotten great response to this....and again not perfect but works for our clients in both cost and approach.

If you want more information on the product;

Kindest Regards,

Jim Porter

Collapse -

NEVER rely on ONE backup system

by TomSal In reply to just another thought

Take you stance to praise --- SAN (hardware) backup or tape solutions...I don't care.

Should use BOTH, not one or the other.

What happens if the hardware fails? What happens if the tape fails?

Collapse -

Dont forget to test your Backup

by Fridolyn In reply to Determine your tape backu ...

For our web hosting cluster whit about 350 GB Diskspace we have a backup scheme with full backups every 14 days and various levels of incremental in between. So for a restore we need in any case a maximum of 5 storage sets (full, level5, level 3 and max 2 incremental). We are using Solstice Disk Suite (Legato Netwoker) and a 21 Slot DLT8000 library so the scheduling is not much a hassle, I have just to change tapes every 14 Days.

The changed tapes are stored in another building across a big street and two railway tracks. As long as we don't have a huge bomb or a big earthquake either the tapes or the data will survive.
But I stumbled over another very important issue, TEST YOUR BACKUP OFTEN. I installed the Software, made a backup and restored it, worked fine, so nothing more to do I thought.

After two months I had to install a bigger disk in my personal workstation, so I decided to test my backup and perform a disaster recovery. I made a full backup during one night, the next day I exchanged the disks installed the software in order to recover and started the recover procedure. But the backup software was not able to find my savesets on the tapes.

A longer investigation showed that we had only the last saveset on each tape, due to a configuration error the tape rewound before each new saveset (a saveset is a tape file which contains all files in a given backup from one partition of one machine).

Well I installed the old disk again and had my data back again, but I don't dare to think about what would happen if I only discovered this problem while performing a disaster recover of the productive web server farm after a real disaster..............................

Related Discussions

Related Forums