11-14-2012 02:49 PM
RMAN backup is runnning very slow, average speed is 1MB/sec. How to find out what is making the backup slow.
Around 100 GB DB is taking 14 hours to complete the backup. It was taking only 4-5 hours to complete the Tape backup before, now we have moved this oracle backup to Data Domain ATMOS storage. Not sure why it is running very slow, Data Domain mean it should complete fast right.
Help me to find out what is wrong, that making the backup slow.
Please let me know how to proceed and which are the logs required to bottleneck this issue.
11-14-2012 03:54 PM
Help us to understand backup parameters in rman script.
filesperset value? How many channels?
Datadomain recommends filesperset of 1 and multiple channels (sbt_tape).
11-14-2012 06:41 PM
On what point did you determine average speed? Average tranfer for each backup jobs? Or by DB size devide backup elapsed time?
I assume you determined by formar way because of extremely low performance. On RMAN stream backup, Oracle does not pass whole database blocks to NetBackup - only used blocks. So backup size will be lower than database size. If only few GB(or MB) is used, average transer seems very low from NetBackup.
Even if only part of database space is used, Oracle read whole database space to check its consistency. So if space usage is low, read performance at oracle side become key factor. You should check disk read performance and busy rate on Oracle host.
11-15-2012 11:07 PM
For my backup same problem here..( Dead Slow) .could you please me out?
11-17-2012 10:45 PM
SID SERIAL# SOFAR TOTALWORK Blocks/sec Mins to go START_TIME LAST_UPDATE_TIME % COMPLETE
---------- ---------- ---------- ---------- ---------- ---------- -------------------- -------------------- ----------
16 11 2242104 6102080 146 439 17-nov-2012 18:59:16 17-nov-2012 23:14:07 36.74
17 23 1582200 8925568 103 1183 17-nov-2012 18:59:19 17-nov-2012 23:14:07 17.73
23:20:00 %usr %sys %wio %idle
Average 3 11 1 85
load averages: 0.66, 0.60, 0.54; up 119+02:57:57 23:19:42
101 processes: 100 sleeping, 1 on cpu
CPU states: 92.3% idle, 2.3% user, 5.2% kernel, 0.2% iowait, 0.0% swap
Memory: 16G phys mem, 7957M free mem, 15G total swap, 15G free swap
11-19-2012 06:27 PM
Sorry, I have mis-understood as you use ATMOS as primary storage. You used ATMOS as backup destination.
So, first thinfg you should to do is measuring ATMOS performance on your media server. Check activity with tools like iostat, perfmon or so. depending on your OS and how you configure the access(NFS/CIFS/...) to ATMOS. Or do performance test with backup of large local files.
12-07-2012 02:03 PM
We had issues because all the backups were running at a time and the backup was running slow. We have created seperate storage unit for this RMAN backups and all the backups are running fine now.