We've recently virtualised a SBS 2008 (Hyper-V) on to a Server 2012 R2 Host, as the disk space had become critical and we needed to maintain the SBS whilst we work out a migration plan away from SBS.
The SBS 2008 was virtualised using Shadow Protect and then restored into a virtual machine on the Server 2012 R2 Host. This has a dual processor Dell R730 server with 32GB of RAM and 8 x 1.2TB 10K SAS disks arranged in a RAID 10 configuration.
The previous backup was performed using Shadow Protect to physical USB disks which were rotated each night and taken off-site, generally the whole backup would be completed in about four to five hours.
I've found that since virtualising, that if we patch through the USB directly onto the virtual (take the disk off-line on the host) and then add it to the client SBS, then the backup takes about three to four hours and works o.k. However, each time the backup drive is disconnected then we have to perform the whole operation again. We see a throughput of about 40MB/sec.
If we try to patch through the host - map a drive through the host so the client virtual machine can see the USB drive like a mapped network drive - then the backup process takes forever (18 hours) and we see a throughput of about 8MB/sec.
I've looked at maybe backing up to NAS using iSCSI but I still have the issue of getting the backup off-site.
Ideally I'm looking for a solution (still use Shadow Protect) but one that allows me to either continue using USB's rotated off-site as the client is used to doing this and it works quite well. Or maybe to a local NAS and then replicate that backup to our own NAS or something similar - ideally with as little overhead as we had before with the rotation of the USB drives or similar - that works and is fast!
The questions I'm asking are:
1) With the setup I have is USB backup a non-starter without lots of admin overhead?
2) How do other people backup virtual machines - if not using USB drives?
Thanks for all your replies and help.