Tape backups: do you always verify them after doing them ?

Thread Tools Search this Thread
Operating Systems AIX Tape backups: do you always verify them after doing them ?
# 1  
Old 08-14-2009
Data Tape backups: do you always verify them after doing them ?

It may seam a bit odd that I ask this question.

After you have done your backups to tapes, do you verify the content of the tapes ?

- never
- sometimes
- always

The reason I am asking is that here in the office, all the backup procedures include verifying the content of the tapes (no matter if it is a savevg, mksysb or Tar). The only reason I can think of for doing this is that the tapes/drives here are not 100% reliable as we sometimes get errors on verifications (5-10% of the times). If they were 100% reliable, then I do not see why we would have to verify all the backups. It just adds up to the amount of work to do during those days.
# 2  
Old 08-15-2009
Are you talking something like DDS/3? I'm not surprised. Newer technologies are more reliable and have better mechanisms for guaranteeing that the data is written accurately.

When I was doing ufsdump to DDS/3, I always used the option that verified the tape. In addition to that, I would test recover data periodically.

Now I'm using AIT5, and I'm using Amanda. I periodically check my backup procedures and recover some files to make sure things are working, but I don't run a verify every time.
# 3  
Old 08-16-2009
Test recovery from media is always the most reliable way provided you can spare the time and equipment to do it.

It can be huge effort depending on what you want to recover.

Usually after 2-3years must replace backup media because they will start to degrade. Replacing media can be very expensive endeavor especially if you use things like LTO and your backups run into several hundred tapes, it can cost a small fortune.
# 4  
Old 08-16-2009
Think this is covered by one of Murphy's laws. IIRC it states that the one file that is sure to corrupt is the one file that corrupted on your last backup. Or something.

I recognize that verification is a user of significate resources but unverified backups can't be trusted. You are playing "bet your business".

My customers are on SCO, not AIX, and their backups are verified then stored in two different places each night.
# 5  
Old 08-20-2009
We are not using any options to verify the tape. We are manually doing a software reading test on the tapes to see if they are readable.

if a backup was done with Tar, we verity the tape with tar tvf
if a backup was done with mksysb, we do an lsmksysb on it
if a backup was done with savevg, we use smit option to list the tape content
# 6  
Old 08-21-2009
Yes, It is always good to verify the tapes after backup. This way you will be sure no corruption has occured.

If it is really important data, try restoring the backed up data on temporary filesystem and make sure everything is working.
Login or Register to Ask a Question

Previous Thread | Next Thread

10 More Discussions You Might Find Interesting

1. AIX

Best method to encrypt AIX LTO6 tape backups?

Hello, I need to be able to encrypt LTO tapes that our AIX writes to for backups. We have a tape library (IBM TS3100) that our AIX host uses to write to LTO6 tapes. We then take those tapes off-site and restore to another AIX system using a 3580-H6S LTO6 tape drive - this is a very simple... (3 Replies)
Discussion started by: c3rb3rus
3 Replies

2. UNIX for Dummies Questions & Answers

Question about a tape write error doing backups

Hello all. UNIX dummy here :p Anyway I was trying to do a full backup of my work server SUN SPARC SERVER 1000 machine (yes we are actually using this dinosaur). I did the ufsdump comand and everything was fine until I got to the dumping of regular files. During the run I got the following... (7 Replies)
Discussion started by: hammerva
7 Replies

3. AIX

Backup with Pax command. How to verify tape?

Dear all experts online, In my environment of AIX 5300-07, I am currently using "pax" command to backup all filesystems that I need to backup and it will take me around 4 hours time with LTO3 tape drive. When I need to verify the tape after backup, I am using "pax" command to list all files in... (2 Replies)
Discussion started by: kwliew999
2 Replies

4. AIX

How to optimize our tape backups ?

Hi, I am currently looking at how we can optimize and speed up our backups here. I am just a beginner operator and our system admin hardly knows anything (long term interim). There is this particular TAR backup of DB backups that for a 10.5Gb amount of files, it takes 5 hours to do the backup on... (6 Replies)
Discussion started by: Browser_ice
6 Replies

5. Solaris

Remote Backups to a Tape

My tape library is broken but backups still need to go on .I have 2 boxes running Solaris 10 Got SCSI tape drive attached to the DEV box ( my PROD Box has only fibre) I want to take the prod backup from the DEV box using ufsdump. ie /usr/sbin/ufsdump 0uvf DEV:/dev/rmt/1n... (2 Replies)
Discussion started by: Msororaji
2 Replies

6. Filesystems, Disks and Memory

Tape drives used for taking backups

Hi, I am a abit new in AIX system administration field. I want to gather knowledge about backup techniques. As per my knowledge we use Tape archives for taking backups. Can anyone pls explain me in detail abt tape archive? Whether these tape archives come along with the systems or we have to... (1 Reply)
Discussion started by: forumsrahul
1 Replies

7. SCO

SCO Backups and Verify Log

Hi, I am after using TAR to backup to tape in SCO 5 but i want to produce a log that tells me that the backup has been successful. Any Suggestions (1 Reply)
Discussion started by: jfd7000
1 Replies

8. UNIX for Dummies Questions & Answers

verifying tape backups

Hello all, how would i go about verifying that a tape is backing up data correctly other than restoring the backup. for example, what command would i use to check the tape for errors? Any and all help is appreciated -Coffee (0 Replies)
Discussion started by: coffeebrown
0 Replies

9. AIX

backups getting it so the tape doesn't rew.

Currently am running the backup command for AIX 5L and see that the tape is rewinding after the completion of the back. backup -0 -u -f /dev/rmt0 / >> $file 2>&1 What can I do to stop allow the backup to rew after the completion of this job? Any thoughts? Thanks again. (2 Replies)
Discussion started by: justinburbridge
2 Replies

10. UNIX for Dummies Questions & Answers

Multiple backups on one tape

For those with backup tapes (and I just bought and installed a Seagate one for my FreeBSD box) I want to know how to get the most out of each tape by placing multiple backups on each tape (potentially 20GB). Please correct me if I'm wrong: First, retension the tape: # mt retension next, turn... (3 Replies)
Discussion started by: WIntellect
3 Replies
Login or Register to Ask a Question