I'm attempting to run a very simple Java program on unix box using
command:

java -jar HelloWorld.jar

and experience the following error

Error occurred during initialization of VM
Could not reserve enough space for object heap
Could not create the Java virtual machine.

If I run the "top" and "free" unix commands I can't see why there
might be a problem freeing up memory to allocate to the JVM, unless
I'm missing something obvious.  Any ideas please help. Thanks.

See below for "top" and "free" output:

top:

top - 07:57:22 up 21 days, 14:42,  3 users,  load average: 0.16, 0.07,
0.02
Tasks:  46 total,   1 running,  45 sleeping,   0 stopped,   0 zombie
Cpu(s):  0.1% us,  0.1% sy,  0.0% ni, 99.8% id,  0.0% wa,  0.0% hi,
0.0% si
Mem:   6097220k total,  6081344k used,    15876k free,    12584k
buffers
Swap: 12586916k total,  6277504k used,  6309412k free,   355436k
cached

 PID USER      PR  NI  VIRT  RES  SHR S %CPU %MEM    TIME+
COMMAND
   1 root      16   0  1628  516  492 S    0  0.0   0:03.66
init
30158 root      15   0  1532  512  444 S    0  0.0   0:08.01
syslogd
30175 root      16   0  4012  796  708 S    0  0.0   0:11.42
sshd
30193 root      18   0  2080  600  596 S    0  0.0   0:00.00
xinetd
30209 root      16   0  3716  296  260 S    0  0.0   0:00.00
vsftpd
30285 root      18   0  2152  896  892 S    0  0.0   0:00.00
mysqld_safe
30331 mysql     16   0  123m 4856 3036 S    0  0.1   1:02.25
mysqld
30508 cyrus     16   0  4424  960  860 S    0  0.0   0:01.50 cyrus-
master
30523 cyrus     18   0 29420 1488 1484 S    0  0.0   0:00.00
imapd
30524 cyrus     17   0 29420 1488 1484 S    0  0.0   0:00.00
imapd
30525 cyrus     18   0 29192 1488 1484 S    0  0.0   0:00.00
pop3d
30527 cyrus     18   0 29192 1484 1484 S    0  0.0   0:00.00
pop3d
30533 cyrus     18   0 29420 1488 1484 S    0  0.0   0:00.00
imapd
30535 cyrus     18   0 29192 1488 1484 S    0  0.0   0:00.00
pop3d
30626 root      16   0  5104 1344 1264 S    0  0.0   0:01.01
master
30636 postfix   15   0  5204 1352 1292 S    0  0.0   0:00.11
nqmgr
30645 cyrus     17   0 29420 1488 1484 S    0  0.0   0:00.00
imapd
30646 cyrus     18   0 29420 1488 1484 S    0  0.0   0:00.00
imapd
30647 cyrus     18   0 29420 1488 1484 S    0  0.0   0:00.00
imapd
30648 cyrus     17   0 29192 1488 1484 S    0  0.0   0:00.00
pop3d
30704 root      23   0  296m  39m 4120 S    0  0.7   4:42.30
java
31817 root      16   0 49580  15m 7848 S    0  0.3   0:16.25
httpd
31837 root      16   0  2480  592  544 S    0  0.0   0:00.06
crond
31867 root      18   0  4052  540  536 S    0  0.0   0:00.00
saslauthd
31868 root      18   0  4052  228  224 S    0  0.0   0:00.00
saslauthd
20271 tomcat    17   0  452m  79m 4592 S    0  1.3  11:32.21
java
32765 cyrus     18   0 29328 1652 1648 S    0  0.0   0:00.00
lmtpd
7501 root      16   0 39384 6156  140 S    0  0.1   0:00.00
httpd
7510 apache    15   0 49692  10m 2648 S    0  0.2   0:00.15
httpd
13886 apache    15   0 49724  10m 2676 S    0  0.2   0:00.12
httpd
13908 apache    15   0 49724  10m 2636 S    0  0.2   0:00.15
httpd
11293 root      17   0  6632 1980 1628 S    0  0.0   0:00.01
sshd

free:

            total       used       free     shared    buffers
cached
Mem:       6097220    6081544      15676          0      30924
356504
-/+ buffers/cache:    5694116     403104
Swap:     12586916    6277504    6309412