Update README.md

README.md

@@ -1,4 +1,52 @@
-How to backup all KVM instances on a TrueNAS Scale, 
+**usage**
+
+```
+root@guile[/mnt/downloads/virt-back]# ./virt-back --help
+Usage: virt-back [options]
+
+A backup utility for QEMU, KVM, XEN, and Virtualbox guests. Virt-back is a
+python application that uses the libvirt api to safely  shutdown, gzip, and
+restart guests.  The backup process logs to syslog for auditing and virt-back
+works great with cron for scheduling outages. Virt-back has been placed in the
+public domain and  the latest version may be downloaded here:
+https://git.unturf.com/python/virt-back
+
+Options:
+  -h, --help            show this help message and exit
+  -q, --quiet           prevent output to stdout
+  -d, --date            append date to tar filename [default: no date]
+  -g, --no-gzip         do not gzip the resulting tar file
+  -a amount, --retention=amount
+                        backups to retain [default: 3]
+  -p 'PATH', --path='PATH'
+                        backup path [default: '/KVMBACK']
+  -u 'URI', --uri='URI'
+                        optional hypervisor uri
+
+  Actions for info testing:
+    These options display info or test a list of guests.
+
+    -i, --info          info/test a list of guests (space delimited dom names)
+    --info-all          attempt to show info on ALL guests
+
+  Actions for a list of dom names:
+    WARNING:  These options WILL bring down guests!
+
+    -b, --backup        backup a list of guests (space delimited dom names)
+    -r, --reboot        reboot a list of guests (space delimited dom names)
+    -s, --shutdown      shutdown a list of guests (space delimited dom names)
+    -c, --create        start a list of guests (space delimited dom names)
+
+  Actions for all doms:
+    WARNING:  These options WILL bring down ALL guests!
+
+    --backup-all        attempt to shutdown, backup, and start ALL guests
+    --reboot-all        attempt to shutdown and then start ALL guests
+    --shutdown-all      attempt to shutdown ALL guests
+    --create-all        attempt to start ALL guests
+```
+
+How to backup zfs snapshot all KVM instances on a TrueNAS Scale, 
 
 ```
 root@guile[/mnt/downloads/virt-back]# ./virt-back -u "qemu+unix:///system?socket=/run/truenas_libvirt/libvirt-sock" --backup-all --path /mnt/personal/backup/virt-back --no-gzip --retention 5