Veritas Volume Manager 4.1 Administrator's Guide (HP-UX 11i v3, February 2007)

Chapter 9, Administering Volume Snapshots
Creating a Shared Cache Object
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increase the size of the cache manually as described in “Growing and Shrinking a Cache”
on page 297, or use the vxcache set command to reduce the value of highwatermark
as shown in this example:
# vxcache -g mydg set highwatermark=60 cobjmydg
You can use the maxautogrow attribute to limit the maximum size to which a cache can
grow. To estimate this size, consider how much the contents of each source volume are
likely to change between snapshot refreshes, and allow some additional space for
contingency.
If necessary, you can use the vxcache set command to change other autogrow attribute
values for a cache. See the vxcache(1M) manual page for details.
Caution Ensure that the cache is sufficiently large, and that the autogrow attributes are
configured correctly for your needs.
Growing and Shrinking a Cache
You can use the vxcache command to increase the size of the cache volume that is
associated with a cache object:
# vxcache [-g diskgroup] growcacheto cache_object size
For example, to increase the size of the cache volume associated with the cache object,
mycache, to 2GB, you would use the following command:
# vxcache -g mydg growcacheto mycache 2g
To grow a cache by a specified amount, use the following form of the command shown
here:
# vxcache [-g diskgroup] growcacheby cache_object size
For example, the following command increases the size of mycache by 1GB:
# vxcache -g mydg growcacheby mycache 1g
You can similarly use the shrinkcacheby and shrinkcacheto operations to reduce
the size of a cache. See the vxcache(1M) manual page for more information.