I've been running ZFS on a machine with 768 MB of RAM and there have been no issues. If you set the size of the ARC cache according to your needs and you do no

I've been running ZFS on a machine with 768 MB of RAM and there have been no issues. If you set the size of the ARC cache according to your needs and you do not use deduplication then you won't encounter any issues. Deduplication requires a giant hash table and is rarely beneficial.