Veritas 5.0.1 Installation Guide HP-UX 11i v3 (5900-2464, September 2012)

The intent log recovery feature is not readily apparent to users or a system administrator,
except during a system failure. During system failure recovery, the VxFS fsck utility performs
an intent log replay, which scans the intent log, and nullifies or completes file system operations
that were active when the system failed. The file system can then be mounted without completing
a full structural check of the entire file system. Replaying the intent log may not completely
recover the damaged file system structure if there was a disk hardware failure. Hardware
problems may require a complete system check using the fsck utility provided with VxFS.
• Allocation Unit
Allocation units are made up of a series of data blocks. Each allocation unit typically consists
of 32k contiguous blocks. Several contiguous data blocks make up an extent. The extents are
used for file data storage.
Extent Based Allocation
An extent is defined as one or more adjacent blocks of data within the file system. Extent based
allocation offers the following advantages:
• Allows large I/Os for efficiency
• Supports dynamic resizing of disk space
Storage Management for Oracle
For more information on Storage Management for Oracle, see the Veritas Storage Foundation for
Oracle Administrator's Guide at http://docs.hp.com.
20 Introduction