I built a stock Solaris 10 VM in the lab a few weeks ago. After adding the fifth zone to it to host a NIS domain, it started suffering “out of memory” errors like the following:
May 3 14:30:59 sol10-a tmpfs: [ID 518458 kern.warning] WARNING: /tmp: File system full, swap space limit exceeded
May 3 14:31:53 sol10-a tmpfs: [ID 518458 kern.warning] WARNING: /zones/sol10-z5/root/etc/svc/volatile: File system full, swap space limit exceeded
May 3 14:32:10 sol10-a tmpfs: [ID 518458 kern.warning] WARNING: /tmp: File system full, swap space limit exceeded
May 3 14:32:34 sol10-a genunix: [ID 470503 kern.warning] WARNING: Sorry, no swap space to grow stack for pid 5650 (cron)

This is easy to fix if you know Solaris administration, but if not:
-bash-3.00# swap -l
No swap devices configured

This is a problem. The simple answer is to add more swap space, staring with a new disk to *host* the swap space. I added a 2GB thin-provisioned disk to the ESX VM, rebooted it, then ran the following:
-bash-3.00# devfsadm
-bash-3.00# format
Searching for disks...done

AVAILABLE DISK SELECTIONS:
0. c1t0d0 <default cyl 4092 alt 2 hd 128 sec 32>
/pci@0,0/pci15ad,1976@10/sd@0,0
1. c1t1d0 <default cyl 2085 alt 2 hd 255 sec 63> zones
/pci@0,0/pci15ad,1976@10/sd@1,0
2. c1t2d0 <default cyl 1021 alt 2 hd 128 sec 32>
/pci@0,0/pci15ad,1976@10/sd@2,0
Specify disk (enter its number): 2
selecting c1t2d0
[disk formatted]

FORMAT MENU:
disk - select a disk
type - select (define) a disk type
partition - select (define) a partition table
current - describe the current disk
format - format and analyze the disk
fdisk - run the fdisk program
repair - repair a defective sector
label - write label to the disk
analyze - surface analysis
defect - defect list management
backup - search for backup labels
verify - read and display labels
save - save new disk/partition definitions
inquiry - show vendor, product and revision
volname - set 8-character volume name
!<cmd> - execute <cmd>, then return
quit
format> fdisk
No fdisk table exists. The default partition for the disk is:

a 100% "SOLARIS System" partition

Type "y" to accept the default partition, otherwise type "n" to edit the
partition table.
y
format> part

PARTITION MENU:
0 - change `0' partition
1 - change `1' partition
2 - change `2' partition
3 - change `3' partition
4 - change `4' partition
5 - change `5' partition
6 - change `6' partition
7 - change `7' partition
select - select a predefined table
modify - modify a predefined partition table
name - name the current table
print - display the current table
label - write partition map and label to the disk
!<cmd> - execute <cmd>, then return
quit
partition> print
Current partition table (original):
Total disk cylinders available: 1020 + 2 (reserved cylinders)

Part Tag Flag Cylinders Size Blocks
0 unassigned wm 0 0 (0/0/0) 0
1 unassigned wm 0 0 (0/0/0) 0
2 backup wu 0 - 1019 1.99GB (1020/0/0) 4177920
3 unassigned wm 0 0 (0/0/0) 0
4 unassigned wm 0 0 (0/0/0) 0
5 unassigned wm 0 0 (0/0/0) 0
6 unassigned wm 0 0 (0/0/0) 0
7 unassigned wm 0 0 (0/0/0) 0
8 boot wu 0 - 0 2.00MB (1/0/0) 4096
9 unassigned wm 0 0 (0/0/0) 0

partition> 0
Part Tag Flag Cylinders Size Blocks
0 unassigned wm 0 0 (0/0/0) 0

Enter partition id tag[unassigned]: swap
Enter partition permission flags[wm]:
Enter new starting cyl[1]:
Enter partition size[0b, 0c, 1e, 0.00mb, 0.00gb]: 2g
`2.00gb' is out of range
Enter partition size[0b, 0c, 1e, 0.00mb, 0.00gb]: 1.99g
partition> print
Current partition table (unnamed):
Total disk cylinders available: 1020 + 2 (reserved cylinders)

Part Tag Flag Cylinders Size Blocks
0 swap wm 1 - 1019 1.99GB (1019/0/0) 4173824
1 unassigned wm 0 0 (0/0/0) 0
2 backup wu 0 - 1019 1.99GB (1020/0/0) 4177920
3 unassigned wm 0 0 (0/0/0) 0
4 unassigned wm 0 0 (0/0/0) 0
5 unassigned wm 0 0 (0/0/0) 0
6 unassigned wm 0 0 (0/0/0) 0
7 unassigned wm 0 0 (0/0/0) 0
8 boot wu 0 - 0 2.00MB (1/0/0) 4096
9 unassigned wm 0 0 (0/0/0) 0
[611/1860]
partition> label
Ready to label disk, continue? y

partition> quit

FORMAT MENU:
disk - select a disk
type - select (define) a disk type
partition - select (define) a partition table
current - describe the current disk
format - format and analyze the disk
fdisk - run the fdisk program
repair - repair a defective sector
label - write label to the disk
analyze - surface analysis
defect - defect list management
backup - search for backup labels
verify - read and display labels
save - save new disk/partition definitions
inquiry - show vendor, product and revision
volname - set 8-character volume name
!<cmd> - execute <cmd>, then return
quit
format> label
Ready to label disk, continue? y

format> quit
-bash-3.00# swap -a /dev/dsk/c1t2d0s0
-bash-3.00# swap -l
swapfile dev swaplo blocks free
/dev/dsk/c1t2d0s0 32,192 8 4173816 4173816
-bash-3.00# echo "/dev/dsk/c1t2d0s0 - - swap - no -" >> /etc/vfstab

To recap:
devfsadm
format
2
fdisk
y
part
print
0
swap

1.99g
label
y
quit
label
y
quit
swap -a /dev/dsk/c1t2d0s0
swap -l
echo "/dev/dsk/c1t2d0s0 - - swap - no -" >> /etc/vfstab

yes, one of those is a blank line to accept the default cylinder “1”.
The info for this post was taken very directly from UtahSysAdmin.com. Huge thank you to Kevin for his post, which I needed to modify slightly to get my VM running.

EDIT: I am currently unsure if the last “echo” statement is right. After a recent reboot, swap wasn’t mounted untill I removed that entry from /etc/vfstab. Soliciting comments. Thanks!