Sunday, December 10

Monitoring RMAN I/O performance

When trying to cut rman backup times there are a lot of parameters to try to tune, database settings, storage subsystem settings, file system settings etc etc.
It can sometimes be hard to remember all the results you get, luckily Oracle keeps them for you. Just query the v$rman_backup_job_details view for the results.

Example:
column END_TIME format a16
column START_TIME format a16
column COMMAND_ID format a20

select
command_id,
to_char(start_time,'YYMMDD HH24:MI') start_time,
to_char(end_time,'YYMMDD HH24:MI') end_time,
round(input_bytes/1024/1024) backup_size,
round(INPUT_BYTES_PER_SEC/1024/1024) in_mb_sec,
round(OUTPUT_BYTES_PER_SEC/1024/1024) out_mb_sec
from
v$rman_backup_job_details
where
start_time > sysdate - 7
order
by start_time
/

COMMAND_ID START_TIME END_TIME BACKUP_SIZE IN_MB_SEC OUT_MB_SEC
-------------------- ---------------- ---------------- ----------- ---------- ----------
2006-12-10T00:34:25 061210 00:35 061210 00:45 13722 22 10
2006-12-10T23:17:48 061210 23:17 061210 23:26 13784 26 12

2 comments:

Don said...

Why not just use input_bytes_display, input_bytes_per_sec_display, and output_bytes_per_sec_display for the last 3 columns that you select?

Sun Flower said...

One of the best ways to monitor your server’s I/O subsystem is to use the PhysicalDisk Object: Avg. Disk Queue Length to monitor each disk array in your server. If the Avg. Disk Queue Length exceeds 2 for continuous periods (over 10 minutes or so) for each individual disk drive in an array, then you probably have an I/O bottleneck for that array. You will need to calculate this figure because Performance Monitor does not know how many physical drives are in arrays sbobetaprender poker