To get a useful answer you'll need to provide the community with more information about the configuration you have.
Q) What filesystem are you using? UFS, VxFS, ZFS, PXFS, etc?
Q) What disk management are you using? SVM, VxVM, ZFS, etc?
Q) Are the disks/LUNs directly presented to the non-global zone or are they mounted using loopback (lofs) to the global zone?
Q) What array or disks are you using as the backing storage device?
Q) What version of Cluster are you using? (I'm assuming Sun/Oracle Cluster here)
In principle you would choose one of the following depending on your scenario:
IF (the storage is presented from a RAID array AND the filesystem is either UFS or VxFS AND you're using either VxVM or SVM)
Grow the LUN's within the array then use the appropriate growfs command for the filesystem in question
IF (the storage is presented from a RAID array AND the filesystem is ZFS)
Read the man page for zpool, and look at the 'autoexpand' property which is disabled by default
autoexpand=on | off
Controls automatic pool expansion when the underlying
LUN is grown. If set to on, the pool will be resized
according to the size of the expanded device. If the
device is part of a mirror or raidz then all devices
within that mirror/raidz group must be expanded before
the new space is made available to the pool. The default
behavior is off. This property can also be referred to
by its shortened column name, expand.
Grow the LUN within the array.
If the new size isn't seen then export/import the zpool.
If the new size still isn't seen by ZFS you've hit Bug 6430818: Solaris needs mechanism of dynamically increasing lun size
An IDR is available and the issue will be fixed in S10u11. Log a service request and we can provide the IDR upon request.
ELIF (the storage is presented from a RAID array AND the filesystem is ZFS AND you want to avoid Bug ID 6430818)
Create a new LUN within the array
Present it to the hosts
Use 'zpool add' to add the new LUN to the zpool and the zpool will immediately grow and present the increased size to the filesystems. No downtime required.
IF (the storage is a JBOD and AND the filesystem is UFS under SVM control)
Create new sub-metadevices using the new devices
Add the new sub-metadevices to existing the existing top-level metadevices
Use growfs to grow the filesystem
IF (the storage is a JBOD and AND the filesystem is either UFS OR VxFS under VxVM control)
Add the new disks to the Vx Volume
Use the appropriate growfs command to grow the filesystem
There are plenty of other options available so if you provide more info and you'll get a more accurate response.