sysadmin.doc: add tip about high ZFS memory usage

diff --git a/sysadmin.adoc b/sysadmin.adoc
index b27bf6f..37d0ffc 100644 (file)
--- a/sysadmin.adoc
+++ b/sysadmin.adoc
@@ -238,6 +238,9 @@ If you have more than one disk, you can also select ZFS here. ZFS
 supports several software RAID levels, so this is specially useful if
 you do not have a hardware RAID controller.
 
+TIP: ZFS uses a lot of memory, so it is best to add additional 8-16GB RAM
+if you want to use ZFS.
+
 The next pages just asks for basic configuration options like time
 zone and keyboard layout. You also need to specify your email address
 and select a superuser password.