InfoScale™ 9.0 Storage and Availability Management for DB2 Databases - AIX, Linux
- Section I. Storage Foundation High Availability (SFHA) management solutions for DB2 databases
- Overview of Storage Foundation for Databases
- About Veritas File System
- Overview of Storage Foundation for Databases
- Section II. Deploying DB2 with InfoScale products
- Deployment options for DB2 in a Storage Foundation environment
- Deploying DB2 with Storage Foundation
- Deploying DB2 in an off-host configuration with Storage Foundation
- Deploying DB2 with High Availability
- Deployment options for DB2 in a Storage Foundation environment
- Section III. Configuring Storage Foundation for Database (SFDB) tools
- Configuring and managing the Storage Foundation for Databases repository database
- Configuring the Storage Foundation for Databases (SFDB) tools repository
- Configuring authentication for Storage Foundation for Databases (SFDB) tools
- Configuring and managing the Storage Foundation for Databases repository database
- Section IV. Improving DB2 database performance
- About database accelerators
- Improving database performance with Quick I/O
- About Quick I/O
- Improving DB2 database performance with Veritas Concurrent I/O
- Section V. Using point-in-time copies
- Understanding point-in-time copy methods
- Volume-level snapshots
- Storage Checkpoints
- Considerations for DB2 point-in-time copies
- Administering third-mirror break-off snapshots
- Administering Storage Checkpoints
- Database Storage Checkpoints for recovery
- Backing up and restoring with Netbackup in an SFHA environment
- Understanding point-in-time copy methods
- Section VI. Optimizing storage costs for DB2
- Section VII. Storage Foundation for Databases administrative reference
- Storage Foundation for Databases command reference
- Tuning for Storage Foundation for Databases
- Troubleshooting SFDB tools
Storage Checkpoint space management considerations
Several operations, such as removing or overwriting a file, can fail when a file system containing Storage Checkpoints runs out of space. If the system cannot allocate sufficient space, the operation will fail.
Database applications usually preallocate storage for their files and may not expect a write operation to fail. During user operations such as create or mkdir, if the file system runs out of space, removable Storage Checkpoints are deleted. This ensures that applications can continue without interruptions due to lack of disk space. Non-removable Storage Checkpoints are not automatically removed under such ENOSPC conditions. Arctera recommends that you create only removable Storage Checkpoints. However, during certain administrative operations, such as using the fsadm command, using the qiomkfile command, and creating a Storage Checkpoint with the fsckptadm command, even if the file system runs out of space, removable Storage Checkpoints are not deleted.
When the kernel automatically removes the Storage Checkpoints, it applies the following policies:
Remove as few Storage Checkpoints as possible to complete the operation.
Never select a non-removable Storage Checkpoint.
Select a nodata Storage Checkpoint only when data Storage Checkpoints no longer exist.
Remove the oldest Storage Checkpoint first.
Remove a Storage Checkpoint even if it is mounted. New operations on such a removed Storage Checkpoint fail with the appropriate error codes.
If the oldest Storage Checkpoint is non-removable, then the oldest removable Storage Checkpoint is selected for removal. In such a case, data might be required to be pushed to a non-removable Storage Checkpoint, which might fail and result in the file system getting marked for a FULLFSCK. To prevent this occurrence, Arctera recommends that you only create removable Storage Checkpoints.