Bigfile000 Exclusive link | Unable To Open Bigfile

This is a common error encountered in specific enterprise backup and data management environments, most notably Commvault (Simpana) and occasionally in Oracle database or Sybase environments.

The error message indicates that the software attempted to open a specific file object (labeled bigfile000) with an exclusive lock but failed because the operating system denied the request. unable to open bigfile bigfile000 exclusive

Here is a detailed write-up of the issue, its causes, and the resolution steps. This is a common error encountered in specific

4. Example Error Messages (Variants)

ORA-27086: unable to open bigfile bigfile000 exclusive
Linux-x86_64 Error: 13: Permission denied
Additional information: 1

ERROR: Could not lock file 'bigfile000' exclusively. Resource temporarily unavailable.

Risks & mitigations

Risk: Revealing PID/host could expose sensitive info — show only when permissible and obfuscate when needed.
Risk: Copying huge files consumes disk space — prefer reflink cloning; warn user about space and offer destination choice.
Risk: Misidentifying lock type on network filesystems — default to conservative options (read-only/copy) and document uncertainty.

Scenario: Commvault (Simpana)

In Commvault, bigfile000 usually refers to a specific chunk in a Deduplication Database (DDB) or a standard chunk library. ERROR: Could not lock file 'bigfile000' exclusively

Resolution: Often requires killing the specific job ID, running a "Library Maintenance" check, or restarting the CVD and GxClMgrS services to flush the handle cache.

3. Typical Environments

Oracle Database (Bigfile tablespace): A bigfile tablespace has a single large data file. If the data file bigfile000 can’t be opened exclusively, the database may fail to mount or open.
Custom applications using fopen() with "wx" or O_EXCL flags, or LockFileEx on Windows.
Backup/restore tools that need exclusive access to a file for consistency.

4. Verify Backup Credentials

Ensure the "Logon Account" used by the backup software has Full Control permissions (Read/Write/Modify) on the folder containing the file. While "Access Denied" usually generates a different error code, permission issues can sometimes manifest as inability to open files exclusively.