Well, in general, increasing the size of a filesystem means (1) increasing the partition or physical disk space allocated to the mount point and then (2) running some resize utility specific to the file system. To step (1) you need to know more about the SAN and to reallocate parititon size on it. To step (2) you need the extendfs program, which HP documents here and which probably Veritas documents elsewhere. According to the HP documentation, it seems as if online resizing is supported. (That is no, umount and remount necessary). However, if the underlying disk system is actually an LVM volume, you'll need to unmount, resize the LVM volume using lvextend, then use extendfs and then remount.