Cause of Longer Backup Time

[Sanjiv Sharma_1]

Hi Nibble,

I believe you are taking a local ontape backup of the Informix Database.

You can do the following.

1. Clean the tape drive with a cleaning tape.
2. Take the backup in a new media.
3. Shutown/Startup the Informix database if possible.
4. Restart the Server if possible. Worst Case.

HTH,

[nibble]

hi sanj,

ive already done cleaning the drive, using a new tape and restarting d dbase... we're running the backup now and observing. if still d same, i believe we need to restart the server..

but u guys rule out the data itself that cud grow large? but i guess its too much for an increase of 10-12 hours of backup. this shud be abt 1 or 2 hrs only if data has really grown.

any other possibilities?

[Bill Hassell]

What is the backup method. Most Informix sites run raw volumes so if the backup is simply the raw data, amount of data in the backup will be the same every time. However, if you are exporrting the database into files, write into your backup script a routine that summarizes all the file sizes before the actual backup. The total will give you a better idea of what you are backing up.

Another possibility is that the backup path from disk to tape (is it over a LAN? are there any other computers connected to the dedicated backup LAN?) Modern tape drives are streamers and waste an enormous amount repositioning when the data stream can't keep up with the tape drive. A single misconfigured PC can flood the network with useless packets and destroy the backup throughput.

[JJ_4]

What version of Informix??

When it is running do "onstat -g ath" a few times.

You want to get the stack of the arcbackup1 thread onstat -g stk

[bill summers]

Check syslog for bus hang or SCSI errors.
Could be faulty SCSI connection to DLT.