Veritas File System 5.0 Administrator's Guide (September 2006)

Chapter 4 VxFS I/O Overview
About VxFS I/O ............................................................................ 63
Buffered and Direct I/O ................................................................. 64
Direct I/O ............................................................................. 64
Unbuffered I/O ...................................................................... 65
Data synchronous I/O ............................................................. 65
Concurrent I/O ............................................................................ 66
Cache advisories .......................................................................... 66
Freezing and thawing a file system .................................................. 67
Getting the I/O size ...................................................................... 67
Chapter 5 Storage Checkpoints
About Storage Checkpoints ............................................................ 69
How Storage Checkpoints differ from snapshots ........................... 70
How a Storage Checkpoint works ..................................................... 71
Copy-on-write ....................................................................... 73
Types of Storage Checkpoints ......................................................... 74
Data Storage Checkpoints ........................................................ 74
nodata Storage Checkpoints ..................................................... 75
Removable Storage Checkpoints ................................................ 75
Non-mountable Storage Checkpoints ......................................... 76
Storage Checkpoint administration .................................................. 76
Creating a Storage Checkpoint .................................................. 77
Removing a Storage Checkpoint ................................................ 78
Accessing a Storage Checkpoint ................................................ 78
Converting a data Storage Checkpoint to a nodata Storage
Checkpoint ..................................................................... 80
Space management considerations .................................................. 88
Restoring a file system from a Storage Checkpoint .............................. 89
Restoring a file from a Storage Checkpoint .................................. 89
Storage Checkpoint quotas ............................................................. 94
Chapter 6 Online backup using file system snapshots
About snapshot file systems ........................................................... 95
Snapshot file system backups ......................................................... 96
Creating a snapshot file system ....................................................... 97
Backup examples .......................................................................... 97
Snapshot file system performance ................................................... 98
Differences Between Snapshots and Storage Checkpoints .................... 99
About snapshot file system disk structure ......................................... 99
How a snapshot file system works .................................................. 100
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