updated README

README.md

@@ -1,2 +1,58 @@
 sanoid
 ======
+
+Sanoid is a policy-driven snapshot management tool for ZFS filesystems.
+
+You can use Sanoid to create, automatically thin, and monitor snapshots and pool health from a single eminently human-readable TOML config file at /etc/sanoid/sanoid.conf.  A typical Sanoid system would have a single cron job:
+
+```
+* * * * * /usr/local/bin/sanoid --cron
+```
+
+And its /etc/sanoid/sanoid.conf might look something like this:
+
+```
+[data/home]
+	use_template = production
+[data/images/win2012]
+	use_template = production
+[data/images/win7-spice]
+	use_template = production
+	hourly = 4
+
+#############################
+# templates below this line #
+#############################
+
+[template_production]
+        hourly = 36
+        daily = 30
+        monthly = 3
+        yearly = 0
+        autosnap = yes
+        autoprune = yes
+```
+
+Which would be enough to tell sanoid to take and keep 36 hourly snapshots, 30 dailies, 3 monthlies, and no yearlies.  Except in the case of data/images/win7-spice, which only keeps 4 hourlies for whatever reason.
+
+Sanoid also includes a replication tool, syncoid, which facilitates the asynchronous incremental replication of ZFS filesystems.  A typical syncoid command might look like this:
+
+```
+syncoid data/images/vm backup/images/vm
+```
+
+Which would replicate the specified ZFS filesystem (aka dataset) from the data pool to the backup pool on the local system, or
+
+```
+syncoid data/images/vm root@remotehost:backup/images/vm
+```
+
+Which would push-replicate the specified ZFS filesystem from the local host to remotehost over an SSH tunnel, or
+
+```
+syncoid root@remotehost:data/images/vm backup/images/vm
+```
+
+Which would pull-replicate the filesystem from the remote host to the local system over an SSH tunnel.
+
+Syncoid uses and supports mbuffer buffering, lzop compression, and pv progress bars if the utilities are available on the systems used.