[linux-lvm] ERROR creating snapshot: "Cannot allocate memory"

[Murthy Kambhampaty]

While trying to snapshot a 335 GB LV (sdd1) on a machine with 12 GB of RAM,
and 67 GB of free space (sdc1), I get the following error:

lvcreate -s -l 21 -n snapshot /dev/VGdb01/LVdb
lvcreate -- WARNING: the snapshot will be automatically disabled once it
gets full
lvcreate -- INFO: using default snapshot chunk size of 64 KB for
"/dev/VGdb01/snapshot"
lvcreate -- ERROR "Cannot allocate memory" creating VGDA for
"/dev/VGdb01/snapshot" in kernel

kernel is 2.4.21 (LVM 1.0.5+) with tools form
~redhat/contrib/lvm-1.0.5.src.rpm

Help