> Just because your hardware is capable of doing 64 bit does not mean 
> you 
> installed a 64 bit kernel.
> 
> What is the output of
> 
>   uname -a

The output of "uname -a" is "2.6.18-8.1.14.el5".

The system is definitely 64bit OS. I have checked its memory layout. Totally there is 8G memory and all belong to LowMem. And HighMem is 0.

Here is the output of "cat /proc/meminfo"

[root@wan-koi proc]# cat meminfo
MemTotal:      8178672 kB
MemFree:       6458496 kB
Buffers:        224360 kB
Cached:        1268404 kB
SwapCached:          0 kB
Active:         624884 kB
Inactive:       935680 kB
HighTotal:           0 kB
HighFree:            0 kB
LowTotal:      8178672 kB
LowFree:       6458496 kB
SwapTotal:     2031608 kB
SwapFree:      2031608 kB
Dirty:              32 kB
Writeback:           0 kB
AnonPages:       67784 kB
Mapped:          26556 kB
Slab:           127912 kB
PageTables:       6776 kB
NFS_Unstable:        0 kB
Bounce:              0 kB
CommitLimit:   6120944 kB
Committed_AS:   145356 kB
VmallocTotal: 34359738367 kB
VmallocUsed:    265208 kB
VmallocChunk: 34359472899 kB
HugePages_Total:     0
HugePages_Free:      0
HugePages_Rsvd:      0
Hugepagesize:     2048 kB


Thanks,

wenji