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Re: Hot backup.

 
David Lodge
Trusted Contributor

Re: Hot backup.

Silly question - I've noticed that you are running several consecutive compresses, some of them without parameters (as if compressing stdin->stdout) are you trying to compress all the files at the same time?
(Any chance of seeing that part of the script?)

Another thing - do you get slow downs for anything else? With a memory leak I'd expect the whole system to gradually slowdown, rather than just one process.

How busy is the system generally (bespoke applications etc?)

Have you got any other applications grabbing large amounts of memory? (from memory mib2agt caused a few problems here 'cos it had a big memory leak)

dave
Rushank
Super Advisor

Re: Hot backup.


There is no mib2agt memory leak. I've already checked that. Two compress are running same time with run state some time.
This is a perl script it comresses then do a cp , here is the part of the script

`compress $ARCH_DIR/$ARCHFILE`;
`cp $ARCH_DIR/$ARCHFILE.Z $BACKUP_DATA`;
`mv $ARCH_DIR/$ARCHFILE.Z $OLDARCH_DIR`;
print REST "cp $BACKUP_DATA/$ARCHFILE.Z $ARCH_DIR\n";
David Lodge
Trusted Contributor

Re: Hot backup.

I can tell you for certain that it isn't a memory leak - from the vmstat and ps listing you've provided, memory isn't growing.

I can't see any correlation from time from reboot and CPU usage (one of my first thoughts)...

This leads me to think that it looking more and more to your disc subsystem - why this is refreshing with a reboot is a mystery!

Are you getting any strange errors on dmesg/stm? from your disk devices? I notice you're running MeasureWare Agent - if you have Perfview are your disk access rates climbing?

dave (clutching at straws!)
John Palmer
Honored Contributor

Re: Hot backup.

I also now suspect the disk subsystem may be an issue what is it?

Notice that in the second ps list that you posted the two compresses were only using 57 and 56% CPU whereas the first pair were using 98% and 74%. Not definite but it could be that they are waiting for I/O.

Regards,
John
Christopher Caldwell
Honored Contributor

Re: Hot backup.

Coupla things
1) I doubt you have an N with just 1 CPU, but if you do, I've found that compute intensive apps on HP-UX single processor boxes run better sequentially (no context switching) than in parallel.

2) check your dbc_max_pct, dbc_min_pct tunings. If they're default, your filesystem cache could be consuming up to 50 percent of available memory over time, which might explain why the compress performs well after reboot, but not if the box has been running for a while.
Rushank
Super Advisor

Re: Hot backup.


It's really a mistry and It's driving me nuts.
This is N-Class with 8 cpu. dbc_min and dbc_max are 5 and 8 respectively.

During this backup some time both the compress are in running and some time one in running state. I really don't know how to pin point this problem and why a reboot fixes it initially for few days.




Magdi KAMAL
Respected Contributor

Re: Hot backup.

Hi Rushank,

The post name is "Hot backup", but it seems to me that you are using cold backup when you compress the table space using the "compress" hp-ux command !

You can use RMAN ( oracle recovery manager ) for Hot Full backup ( level 0 )during the weekend and one incremental Hot backup each day using ( Leve l ).

By this you can reduce the time for backup and also the amount of data backed up.

Magdi
Steven Gillard_2
Honored Contributor

Re: Hot backup.

Are you running the measureware agent on your system? If so then it is collecting historical data which will be very useful. If you've got perfview that would make it easier, otherwise I would run an "extract" as follows:

1. Make a copy of /var/opt/perf/reptall somewhere. Edit this file and uncomment the DATA TYPE GLOBAL metrics you would like to look at. I suggest as a start:
DATE
TIME
GBL_MEM_CACHE_HIT_PCT
GBL_CPU_TOTAL_UTIL
GBL_CPU_SYS_MODE_UTIL
GBL_CPU_USER_MODE_UTIL
GBL_CPU_NICE_UTIL
GBL_DISK_UTIL_PEAK
GBL_MEM_UTIL
GBL_MEM_USER_UTIL
GBL_MEM_SYS_UTIL
GBL_MEM_PAGEOUT_RATE
GBL_RUN_QUEUE

2. Run "extract" as follows:

# extract -xp -g -l /var/opt/perf/datafiles/logglob -r reptall -b "today-10" -f perf.txt

That will give you the last 10 days worth of data in the perf.txt file. You can import that file into Excel then graph some of the metrics if you like. You should be able to at least confirm from the above whether you have a disk or CPU bottleneck (it already looks like memory pressure is not the culprit).

Also, it wouldn't hurt for you to run a patch analysis on the system. If you have a support contract you can use the "custom patch manager" on ITRC to generate a system specific patch bundle. There are loads of patches available that fix performance problems.

Regards,
Steve
Rushank
Super Advisor

Re: Hot backup.

Hello,

I 'extracted' data for last 15 days and'm analyzing it. Thanks(Steve) for the tip. The data I collected is now for every 5 minutes interval ; how do I change this interval duration for every 30 minutes or every 1 hour.
and also is there any way I can extract the data only between time 21:00 to 07:00 ?

Thanks in Advance

Steven Gillard_2
Honored Contributor

Re: Hot backup.

You can change the extraction period by using the -b and -e options to specify the start and end time. This information is in the extract man page:

-b