Backup Speed Tuning in DB2

[Zailar]

Hi All,

Anyone knows the Backup speed tuning in DB2?.

I was  test  type "Standart"  backup speed 3232000 kb/sec, but if  type "DB2"  backup speed 8000 kb/sec.

The backup script :

# -----------------------------------------------------------------
# DB2 backup command.
# -----------------------------------------------------------------
CMD="db2 backup database TST"
CMD="$CMD online"
CMD="$CMD $BACKUP_TYPE"
CMD="$CMD load '/usr/openv/netbackup/bin/nbdb2.so64'"
CMD="$CMD open 1 sessions"
CMD="$CMD with 2 buffers"
CMD="$CMD buffer 1024"
CMD="$CMD parallelism 1"
CMD="$CMD exclude logs"
CMD="$CMD without prompting"

DB2 Config

Restrict access = NO
Default query optimization class (DFT_QUERYOPT) = 5
Degree of parallelism (DFT_DEGREE) = ANY
Continue upon arithmetic exceptions (DFT_SQLMATHWARN) = NO
Default refresh age (DFT_REFRESH_AGE) = 0
Default maintained table types for opt (DFT_MTTB_TYPES) = SYSTEM
Number of frequent values retained (NUM_FREQVALUES) = 10
Number of quantiles retained (NUM_QUANTILES) = 20

Thanks

[Michal_Mikulik1]

Hello,

do you probably use Dedup&Accelerator with your Standard policy? Because speed about 3Gb/s seems unbelievable for traditional file backup and common disk/tape targets.

On the other hand, 8MB/s for DB2 backup can be ok in some environments. Especially when databases are smaller.

Regards

Michal

[MJaggi]

Try to increase number of Buffers and sessions.

[Zailar]

Hi Michal,

No Dedup, backup to tape.

others client backup type "DB2" speed can be 20 - 30 MB/sec.

Can be increased if I changes db2 config?

"Degree of parallelism (DFT_DEGREE) = ANY"  to "Degree of parallelism (DFT_DEGREE) = 1"

"We can open case because, the NBU version was EOSL"

[Michael_G_Ander]

Don't know DB2, but usually tuning of a database backup has more to do with the database script/settings than Netbackup.

Looking at your script I think 2 buffers and parallelism 1 look like things that might could be increased to improve performance, but you will have confer with your DB2 DBA.