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Cause of Longer Backup Time

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nibble
Super Advisor

Cause of Longer Backup Time

hi guys, what are the possible reasons why backup of informix (ontape) would take longer that the usual time?? from 2 hrs it became 15 hrs... this 2 hours duration has been the average for 3 yrs... cud there be any configuration problem? how abt disk spaces for db...btw, its an informix on top of ux11.00
14 REPLIES
MarkSyder
Honored Contributor

Re: Cause of Longer Backup Time

Do you have any performance monitoring tools (e.g. Big Brother) on your system that would show if disc space or anything similar has suddenly become a problem?

Try running top to see if you have any processes hogging processor time.

Mark Syder (like the drink but spelt different)
The triumph of evil requires only that good men do nothing
nibble
Super Advisor

Re: Cause of Longer Backup Time

thanks.. got this one

System: XXX
Wed Jan 28 18:32:24 2004
Load averages: 2.23, 2.40, 2.25
202 processes: 199 sleeping, 2 running, 1 zombie
Cpu states:
CPU LOAD USER NICE SYS IDLE BLOCK SWAIT INTR SSYS
0 2.41 0.6% 0.0% 3.0% 96.4% 0.0% 0.0% 0.0% 0.0%
1 2.06 7.4% 0.0% 8.2% 84.5% 0.0% 0.0% 0.0% 0.0%
2 2.08 4.0% 0.0% 7.0% 89.1% 0.0% 0.0% 0.0% 0.0%
3 2.39 2.8% 0.0% 4.0% 93.2% 0.0% 0.0% 0.0% 0.0%
--- ---- ----- ----- ----- ----- ----- ----- ----- -----
avg 2.23 3.8% 0.0% 5.6% 90.7% 0.0% 0.0% 0.0% 0.0%
Steven E. Protter
Exalted Contributor
Solution

Re: Cause of Longer Backup Time

Lots of possible causes.

The database could be not down properly.

If through a network there could be a configuration, switch or wiring issue.

lanadmin -x 0

change 0 to the real lan number

Could be lack of free space on the /var filesystem where some backups are temporarily spooled.

Check these things.

I'm attaching a performance monitoring script.

SEP
Steven E Protter
Owner of ISN Corporation
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http://hpuxconsulting.com
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nibble
Super Advisor

Re: Cause of Longer Backup Time

i dont find anything unusual here..what do u think?
MarkSyder
Honored Contributor

Re: Cause of Longer Backup Time

The output from top looks fine.

SEP has suggested checking /var - what does bdf show for that?

Mark
The triumph of evil requires only that good men do nothing
nibble
Super Advisor

Re: Cause of Longer Backup Time

all FS are ok. they are less than 60%... probably, this could be database related and database needs to be re-started.

thanks a lot guys
nibble
Super Advisor

Re: Cause of Longer Backup Time

hi SEP, one more thing... should i create the /var/adm/sa/sadd directory? its not existing... sar cant work
Jeff Schussele
Honored Contributor

Re: Cause of Longer Backup Time

Hi nibble,

You must give iterations & time values to sar commands - EX:

sar -d 10 5

This would give stats of 10 iterations five seconds apart.

Rgds,
Jeff
PERSEVERANCE -- Remember, whatever does not kill you only makes you stronger!
Mic V.
Esteemed Contributor

Re: Cause of Longer Backup Time

If you're using a client/server backup (I assume you are), check the backup server. I've seen situations slow backups influenced by tape drives going bad, media with errors, SCSI cards going bad, inability to stream enough data to tape, someone clogging the network with unusual data transfers...

For example, with Legato Networker, you can watch (via nwadmin or nsrwatch) the speed of a tape write. I learned what a "normal" speed was and then I could detect problems.
You can also examine logs created by the backup software (homegrown or otherwise).
What kind of a name is 'Wolverine'?
Sanjiv Sharma_1
Honored Contributor

Re: Cause of Longer Backup Time

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,
Everything is possible
nibble
Super Advisor

Re: Cause of Longer Backup Time

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
Honored Contributor

Re: Cause of Longer Backup Time

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.


Bill Hassell, sysadmin
JJ_4
Frequent Advisor

Re: Cause of Longer Backup Time

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
Not enough Zappa makes you sad.
bill summers
Occasional Contributor

Re: Cause of Longer Backup Time

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