SLOB is an Oracle I/O workload generation tool kit, supports testing extreme REDO logging I/O (minimal amount of CPU overhead)
The SLOB package can be downloaded from Kevin Closson's Blog: SLOB Resources
SLOB 2.4.2 requires Linux with Oracle Client


Unzip the SLOB tar.gz file in the desired directory ($SLOB).
Create tablespace for SLOB data (the script creates IOPS)
$ cd $SLOB
$ sqlplus / as sysdba @ misc/ts
Load SLOB data by running script located in the $SLOB directory. Using two mandatory parameters:
  • Tablespace into which SLOB will create and load the test schemas
  • The number of schemas to create and load
$ ./ IOPS 8


One time compilation
$ cd $SLOB/wait_kit
$ make
Edit runtime parameter in slob.conf configuration file
$ cd $SLOB
$ vi slob.conf
Execute slob using number of SLOB schemas
$ cd $SLOB
$ ./ 8
We can edit the slob.conf file to modify some parameters.
  • UPDATE_PCT - Percentage of SLOB update operations
  • SCAN_PCT - percentage of short scan SELECT operations on a short scan table
  • RUN_TIME - Wall-­clock duration of a SLOB test in seconds
  • WORK_LOOP - SLOB test duration based on iterations
  • SCALE - Number of database blocks / Size
  • SCAN_TABLE_SZ - size of the short scan table(s)
  • WORK_UNIT - scope of blocks being manipulated by each operation
  • REDO_STRESS - HEAVY -> generate significant amounts of redo logging
  • LOAD_PARALLEL_DEGREE - number of Oracle Database sessions concurrently inserting data
  • THREADS_PER_SCHEMA – sessions against each schema
  • DATABASE_STATISTICS_TYPE - “awr” or “statspack.”
  • ADMIN_SQLNET_SERVICE – separate service for admin operations
  • SQLNET_SERVICE_BASE – service for load balance and round robin connection
  • SQLNET_SERVICE_MAX - appended to SQLNET_SERVICE_BASE in a RAC testing scenario
  • DBA_PRIV_USER – sys / system or any DBA user
  • SYSDBA_PASSWD – password of the above user

Results & tools

  • iostat.out - input/output statistics: Read Thoughput (MB/sec), Write Throughput (MB/sec) and information about queue lengths.
  • mpstat.out - CPU utilization (processors related statistics)
  • vmstat.out - virtual memory statistics
  • misc/ - extracts interesting information from the awr.txt file
$ misc/ awr_pdb.txt
awr_pdb.txt||61|0.6|1.0|695|52106|1997| 16.6|0| 53|34.8| 250|0|0|0| 192|DB CPU 33.3 54.7|


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