Veritas Storage Foundation 5.1 SP1 Advanced Features Administrator"s Guide (5900-1503, April 2011)

■ if logmap_len is greater than
loglen/2, vxvol fails with an
error message. Either increase
loglen to a sufficiently large value,
or decrease logmap_len to a
sufficiently small value.
■ The value of logmap_len cannot
exceed the number of bytes in the
on-disk map.
If both logmap_len and loglen are
specified
■ The value is constrained by size of
the log, and cannot exceed the size
of the on-disk map. The size of the
on-disk map in blocks can be
calculated from the following
formula:
round(loglen/nmaps) - 24
where nmaps is 2 for a private disk
group, or 33 for a shared disk group.
■ The value of logmap_len cannot
exceed the number of bytes in the
on-disk map.
If logmap_len is specified
■ Specifying a value that is less than
twice the disk group alignment
value results in an error message.
■ The value is constrained by size of
the logging subdisk.
If loglen is specified
Displaying information
This section describes the following tasks:
■ Determining the setting of the CDS attribute on a disk group
■ Displaying the maximum number of devices in a CDS disk group
■ Displaying map length and map alignment of traditional DRL logs
■ Displaying the disk group alignment
■ Displaying the log map length and alignment
■ Displaying offset and length information in units of 512 bytes
481Migrating data between platforms
Maintaining your system