snapshot deletion stackd at 99% on production server

HI,

On ESXi 4.1 (thick prov) I've only one host with 4 snapshot. There were 20 gb free space on esxi host. I started deletion process with 1st snapshot (40gb) but it stacks at 99% for 2 hour. I used vSphere client.

I ran the following command in command line

# ls -luth |grep -E "delta|flat"

output:

03:30(current time)     server-000002-delta.vmdk

00:07(start time)         server-flat.vmdk

00:07(start time)         server-000004-delta.vmdk

(few year ago)              server-000001-delta.vmdk

(few year ago)              server-000003-delta.vmdk

please help. it is a production server.

Thanks in advance