Creating backups of computer data is nothing new. Each year new techniques and software emerge making it easier for non-geeks to implement backup techniques and automate them. Most businesses and many households use a backup strategy that involves backing up to another computer on the network or even online. I’ll call the computer that needs data backed up the “client” and the computer that is storing the data as a backup the “server” or “remote volume.”
Sometimes the automated connection between the client and server fails. In Mac OS X, I’ve found two different causes for this and below are the fixes for each. I’ve seen reports of these issues occuring with Apple’s Time Machine, Carbon Copy Cloner, Super Duper, Deja Vu and other backup utilties. These issues can also occur with Apple’s Time Capsule.
Remote Volume Names
The first issue is how one names the remote volume. Depending on what protocol you’re connecting with, the name you give the volume may not work with the connection. Try to avoid any special characters, and stick with letters and numbers. Spaces are typically okay.
The next issue with remote volume names is that the name in the Finder does not always match the subsystem name – which is what a backup utility typically uses. For example, I have a server wtih a volume name of “Storage” and that’s what I see in the Finder. However, using the Terminal I can see other names for the same remote volume. Sometimes there will be multiple names listed, and that really confuses backup utilities.
If you can connect to the remote volume through the Finder, but the backup utility will not connect, this is probably the issue. The remote volume is obviously accessible because the Finder can connect. A restart usually fixes this issue, but not always. If the restart doesn’t work or if you don’t want to restart, you will need to use the Terminal application found in the Utilties folder.
Once you have the Terminal open, type:
cd /Volumes/
then
ls
You should now see the volumes that your computer has connected to. In my case, I see several volumes including Storage-1, Storage-2 and Storage-3. Those all need to go away or the backup utility will not connect. Remember, the name of the volume is just plain Storage so when the utility sees those other options, it wont connect to those. Additionally, the Finder will not reconnect using simply Storage because it thinks the volume is already connected. You’ll notice the -# added to each erroneous volume. In my case, -1, -2 and -3. Volumes with those added to them (provided they’re not actually named that) need to go away.
Again in the Terminal, type:
rm Storage-1
Obviously, in your case you should substitute the volume name you need to remove.
NetAuthAgent
The second common snag is the “NetAuthAgent” in OS X. It will often hang and not allow you to connect. The symptoms of this in the Finder is the server showing but being unresponsive. Often this seems like the server may have crashed, but that’s usually not the case. I’ve scoured the web trying to find a fix for this, but all I’ve found are tons of reports of the NetAuthAgent hanging and no fixes for it. The quick fix for the symptom is to use the Activity Monitor (in Utilities) to find the NetAuthAgent. If the name is in red, it has hung. Use the Activity Monitor to Force Quit the process. This should allow you to connect to the server in the Finder, and also allow your backup utilitiy to connect as well.