[linux-lvm] "Cannot allocate memory" creating VGDA

[Paul Warren]

We've now downgraded our server to 2.4 so that we can use snapshotting
in lvm1.  Unfortunately:

woozle:~# lvcreate -s -L3000M -n rootsnapshot  /dev/mainvg/root 

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

woozle:~# free
             total       used       free     shared    buffers cached
Mem:       4010688     149192    3861496          0       1824 22944
-/+ buffers/cache:     124424    3886264
Swap:            0          0          0

This is trying to create a snapshot of a 255GB LV.

Any ideas on this one?

cheers,

Paul