1 .Why does vmware crash on startup when used with lessfs?
VMware tries to use shared writable mmap for paging files but it can't 
detect that it's not always supported.
Workaround: Set "mainMem.useNamedFile=FALSE" in the .vmx file. 
It will disable paging files and VMware will work fine, often with much better performance.
Another workaround is to create a large (sparse) file on lessfs. 
Format the file with your favorit fs and mount it with -o loop. 
You can now run your VM deduplicated from this filesystem. 

Another workaround is to use ietd and iscsi as an intermediate protocol.

2. Can I use lessfs with NFS/IETD or SAMBA?

Samba and lessfs should work fine. NFS works but performance is still an issue.

Ietd and lessfs should also work. You can export an sparse file as ietd disk:
cd /to/your/lessfs/mount
dd if=/dev/zero of=ietddata bs=1 count=0 seek=10000M
# create a 10000M large sparse file

# Add this to your ietd.conf file.
Lun 0 Path=/fuse/ietddata,Type=fileio
