How to check free space in ASM

1. Connect to asm instance:

select name, state, total_mb, free_mb from v$asm_diskgroup;

—————————— ———– ———- ———-

2. Using Grid Control

Go to asm host and select asm instance. Go Administration tab and input asm administration password:

3. Using ASMCMD tool

Please make sure to setup ORACLE_SID and ORACLE_HOME environment variables to ASM instance.

-bash-3.2$ asmcmd -p
ASMCMD [+] > du
Used_MB Mirror_used_MB
12011 12011
ASMCMD [+] >

or run

lsdg command

State    Type    Rebal  Unbal  Sector  Block       AU  Total_MB  Free_MB  Req_mir_free_MB  Usable_file_MB  Offline_disks  Name
MOUNTED  EXTERN  N      N        1024   4096  1048576     40960    37628                0           37628              0  ORADATA/
MOUNTED  EXTERN  N      N        1024   4096  1048576     32768    32675                0           32675              0  ORADATA1/

OUI starts and after prerequisites check, OUI crashes

From java trace file:

Unexpected Signal : EXCEPTION_ACCESS_VIOLATION (0xc0000005) occurred at PC=0x80D7A9C

Got this problem on client workstation (win2000prof). Initially we have attempted to start oracle iODS installation, but installer crasged just after prerequisites check by firt ‘next’ button pressed. Then I’ve checked if is possible to start oracle client installation, but things got even worse, installer crashed just after prerequisites check completed with OUI wondow showed up for 1 sec.

What I have checked next with no luck:

  • user is in administrators group
  • path variable less than 1024
  • windows2000 sp4
  • installation folder is simple c:\install
  • we tested to install just after complete restart (no apps running)
  • no other oracle services running as system services
  • no problem with installation packages (tested on my own workstation)

Ive even suspected CPU issue, on this workstation new core2duo cpu (I still remember problems with installer on
Pentium4 😉

With help from oracle support, problem been resolved by removing unused oracle entries from windows registry (unregisted in oraInventory entries)

CAUSE: Windows registry seem corrupted on the Oracle branch

Oracle 32bin vs. 64 bit: quick test

What is overhead of using 64 bit addressing on oracle 64 bit systems comparing to 32 bit? For few days, I had test hardware in hands, to do quick check on this.

The quick test is on AMD Dualcore Opteron CPUs (HP BL685) running RHEL 5 and oracle

Server config:


8GB total memory

2 sas hard drives in hardware mirror

Oracle configuration:

db_block_size 8K

db_cache_size 1200M

shared_pool_size 300M

Dedicated server. All other parameters are defaults.

Load configuration:

For load simulation, swingbench software from Dominic Giles is used (

Test: Order Entry application

Customers: 10M

Orders: 250K

Number of concurrent connections: 15 (from 1 client)

DB size: about 4GB

Test Results:

RHEL 5 and oracle 32bit

RHEL 5 and oracle 10.2.03 64bit


AVG Response time








For this quick test, it seems that 32bit operations is little faster, this of course what it should be, just to prove on hands.

Note: this test intentions is more for load software familiarization, not academic purposes 🙂 To do more accurate testing required more time and testing, which is not currently available.

DBA future. Will we shift more to business?

For DBA. understanding business required for long time. Without this understanding hardly possible to tune application and db right. How to understand what exactly to tune – what is important to business? What backup and recovery strategy to develop? MTTR and MTBF? How company is confident in paying $500K only for oracle database enterprise edition? All this related to dba.

On the other hand, there are still loads of pure technical work to do, for example (what first comes to mind):

  • Developing and advancing backup and recovery strategy
  • Actual backups testing, restoring and testing
  • Different crash scenarios modeling and recovery testing
  • Recovery documentation and testing
  • Proactive monitoring and analysis
  • Moving data between test and development, sensual data scrambling
  • Maintaining security, patching, auditing, logs analysis
  • New features, new releases, new platforms, docs refresh, etc, etc


All this require time and professionals, and if more integration with business is needed, more resources is needed as well (simply add more resources – Grid Era :) This means, that pure technical DBA certainly will be needed. This is probably area for DBA assistants and regular DBAs. Seniors will probably do more business integration, or delegate this role to separate DBA.