I am having problems getting my head around a small ZFS issue. If I build a fileserver, say for example a 20 x 1TB disk server with zfs and create a file server, it can work fine and I can have RADIZ or RAIDZ2 or whatever. I could create 4 groups of 5 1TB HDD's and do all things like that...It's shared using iSCSI or samba or whatever, desktops and servers can see the files, everything works fine. But one day I run out of space, so I think right, build an exact copy of the one I have so I have another 20 TB server, given me 40TB, but I want nothing to change for the desktops/servers and as far as they know nothing as happened. But my problem is I could set that second server up, but how do I add the space to my existing pools? I create my RAIDZ2 zpools of hard drives, the raid works and everything, but now I want to increase my existing storage. I could go to my first server and simply add the storage to my groups, thus increasing the size...but then if that server fails I will lose all data? will I not? Basically I'm having trouble finding information on what happens when you add a second file server to increase your space. I see lots of guides and documents for 1 device and adding more HDD's to that device, but not when you need to add a second device (run out of HDD space in the device for example) Thanks