rman备份 出现log file sync /control file sequential read 影响生产

bal

os: AIX 5.3
oracle : 10.2.0.4.0

备份时间为0:05 开始 在做rman level 0备份时候，总会产生log file sync /control file sequential read  等待事件，
从而短暂的影响业务的使用。
分析了这个时间段 nmon的报告，和业务高峰时间持平。alert日志没有异常报错。
同时，log file sync   分析了和日常的 user commits  未见特别增加

附上awr

脚本如下： 采用COMPRESSED BACKUPSET

run {
CONFIGURE BACKUP OPTIMIZATION ON;
#configure channel device type disk rate 50m ;  
#CONFIGURE DEVICE TYPE DISK PARALLELISM 4 BACKUP TYPE TO   BACKUPSET;
CONFIGURE DEVICE TYPE DISK PARALLELISM 4 BACKUP TYPE TO COMPRESSED BACKUPSET;
CONFIGURE CONTROLFILE AUTOBACKUP FORMAT FOR DEVICE TYPE DISK TO '$back_path/auto_%F.ctl';                                             
report obsolete;
delete noprompt obsolete;
backup incremental level 0 database format '$back_path/level0_%d_%T_%s.rman'
tag='level 0' include current controlfile
plus archivelog format '$back_path/arch_%d_%T_%s.arc'
delete all input;  
backup spfile format='$back_path/%d_%T_%s.spfile';
backup current controlfile  for standby format='$back_path/%d_%T_%s_4DG.ctl';
backup current controlfile format='$back_path/%d_%T_%s.ctl';
CROSSCHECK archivelog all;
crosscheck backup;
delete noprompt expired backup;
delete expired archivelog all;
}

bal

kevinlin.ora 发表于 2013-4-19 11:13
数据文件上的单块读还可以，所以看整体IO用处不大。看下控制文件和redo相关磁盘的io，我觉得6个控制文件过 ...

SQL> select * from v$log;

    GROUP#    THREAD#  SEQUENCE#      BYTES    MEMBERS ARCHIVED STATUS           FIRST_CHANGE# FIRST_TIME
---------- ---------- ---------- ---------- ---------- -------- ---------------- ------------- -----------
         1          1       2554  838860800          1 NO       CURRENT            25211626339 2013-04-19
         2          1       2552  838860800          1 YES      INACTIVE           25209474632 2013-04-19
         3          1       2553  838860800          1 YES      INACTIVE           25210681957 2013-04-19

kevinlin.ora

数据文件上的单块读还可以，所以看整体IO用处不大。看下控制文件和redo相关磁盘的io，我觉得6个控制文件过多了，贴下V$log信息

Maclean Liu(刘相兵

physical read bytes
8
Total size in bytes of all disk reads by application activity (and not other instance activity) only.

physical read flash cache hits
8
Total number of reads from flash cache instead of disk

physical read IO requests
8
Number of read requests for application activity (mainly buffer cache and direct load operation) which read one or more database blocks per request. This is a subset of "physical read total IO requests" statistic.

physical read requests optimized
8
Number of read requests that read one or more database blocks from the Database Smart Flash Cache or the Exadata Smart Flash Cache.

physical read total bytes
8
Total size in bytes of disk reads by all database instance activity including application reads, backup and recovery, and other utilities. The difference between this value and "physical read bytes" gives the total read size in bytes by non-application workload.

physical read total IO requests
8
Number of read requests which read one or more database blocks for all instance activity including application, backup and recovery, and other utilities. The difference between this value and "physical read total multi block requests" gives the total number of single block read requests.

physical read total multi block requests
8
Total number of Oracle instance read requests which read in two or more database blocks per request for all instance activity including application, backup and recovery, and other utilities.

physical reads
8
Total number of data blocks read from disk. This value can be greater than the value of "physical reads direct" plus "physical reads cache" as reads into process private buffers also included in this statistic.

physical reads cache
8
Total number of data blocks read from disk into the buffer cache. This is a subset of "physical reads" statistic.

physical reads cache prefetch
8
Number of contiguous and noncontiguous blocks that were prefetched.

physical reads direct
8
Number of reads directly from disk, bypassing the buffer cache. For example, in high bandwidth, data-intensive operations such as parallel query, reads of disk blocks bypass the buffer cache to maximize transfer rates and to prevent the premature aging of shared data blocks resident in the buffer cache.

physical reads direct (lob)
8
Number of buffers that were read directly for LOBs

physical reads direct temporary tablespace
8
Number of buffers that were read directly from temporary tablespaces

physical reads for flashback new
8
Number of blocks read for newing (that is, preparing a data block for a completely new change) blocks while flashback database is enabled

physical reads prefetch warmup
8
Number of data blocks that were read from the disk during the automatic prewarming of the buffer cache.

physical write bytes
8
Total size in bytes of all disk writes from the database application activity (and not other kinds of instance activity).

physical write IO requests
8
Number of write requests for application activity (mainly buffer cache and direct load operation) which wrote one or more database blocks per request.

physical write total bytes
8
Total size in bytes of all disk writes for the database instance including application activity, backup and recovery, and other utilities. The difference between this value and "physical write bytes" gives the total write size in bytes by non-application workload.

physical write total IO requests
8
Number of write requests which wrote one or more database blocks from all instance activity including application activity, backup and recovery, and other utilities. The difference between this stat and "physical write total multi block requests" gives the number of single block write requests.

physical write total multi block requests
8
Total number of Oracle instance write requests which wrote two or more blocks per request to the disk for all instance activity including application activity, recovery and backup, and other utilities.

physical writes
8
Total number of data blocks written to disk. This statistics value equals the sum of "physical writes direct" and "physical writes from cache" values.

physical writes direct
8
Number of writes directly to disk, bypassing the buffer cache (as in a direct load operation)

physical writes direct (lob)
8
Number of buffers that were directly written for LOBs

Maclean Liu(刘相兵

physical read IO requests        806,668        868.98        43.05
physical read bytes        7,290,847,232        7,854,002.79        389,135.74
physical read total IO requests        948,209        1,021.45        50.61
physical read total bytes        33,437,694,976        36,020,470.79        1,784,676.29


physical write IO requests        23,777        25.61        1.27
physical write bytes        283,885,568        305,813.30        15,151.88
physical write total IO requests        62,013        66.80        3.31

似乎能提供的IOPS也只有 1100左右   39MB，

基于AWR
rman大约消耗了 160的iops 和 26MB 的IO ，这个Io量并不高啊， 总的来说 IO能力有限