Hello,
Greetings!!!
Currently we are having one DBWR with 4 dbwr_io_slaves & system is in NetApp Storage with 8 cpu's. I feel increasing dbwr process to 1xCPU or 2x no of CPU cores will improve the system performance. any idea?
Environment:
HP-UX
Oracle Database 10g Enterprise Edition Release 10.2.0.4.0 - 64bit
We have done following changes after NetApp implementation
disk_asynch_io=TRUE
filesystemio_options=SETALL
dbwr_io_slaves=4
ALTER SYSTEM RESET db_file_multiblock_read_count SCOPE=SPFILE SID='*';
Below are the dbwr statistics:
dbwr statistic statistic value
---------------------------------------------- ---------------
DBWR checkpoint buffers written 12,836,278
DBWR fusion writes 0
DBWR object drop buffers written 1,763
DBWR parallel query checkpoint buffers written 4,036
DBWR revisited being-written buffer 1
DBWR tablespace checkpoint buffers written 0
DBWR thread checkpoint buffers written 1,753,757
DBWR transaction table writes 6,581
DBWR undo block writes 6,967,648
DEFAULT 8k buffer busy wait 3,245,536
DEFAULT 8k free buffer wait 0
DEFAULT 8k hit ratio 97
DEFAULT 8k write complete 1
wait
buffer is not pinned count 3,974,046,825
buffer is pinned count ##############
change write time 113,885
commit cleanout failures: buffer being written 40
commit cleanout failures: write disabled 0
data block 3,239,864
dirty buffers inspected 1,065,608
flashback log writes 0
free buffer inspected 382,422,694
free buffer requested 417,571,319
hot buffers moved to head of LRU 46,874,546
lob writes 1,876,399
lob writes unaligned 1,876,208
no buffer to keep pinned count 144
physical write IO requests 6,202,118
physical write bytes ##############
physical write total IO requests 15,565,428
physical write total bytes ##############
physical write total multi block requests 6,351,814
physical writes 37,146,489
physical writes direct 22,049,905
physical writes direct (lob) 3,642
physical writes direct temporary tablespace 21,861,535
physical writes from cache 15,096,584
physical writes non checkpoint 35,044,571
pinned buffers inspected 549,802
summed dirty queue length 11,856,553
switch current to new buffer 1,462,350
write clones created for recovery 0
write clones created in background 157
write clones created in foreground 1,905
Thank you,
Ram