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problem connecting to the server - server may not exist or unavailable. Check server name or IP address. Check network connection

I can no longer connect to my time capsule or another backup drive. I use three back up drives and switch every few months. Suddenly, time machine won't let me switch drives... I get the message "There was a problem connecting to the server Time Capsule. The server may not exist or it is unavailable at this time. Check the server name or IP address, check your network connection, and then try again." I haven't made any changes to settings... other than upgrading to El Capitan. I can see all three drives in the finder but cannot connect to two of them. I've tried restarting the TC and computer and the other drives... but nothing changed.


Any help would be greatly appreciated.


Thanks

iMac (27-inch, Late 2012), OS X El Capitan (10.11)

Posted on Oct 5, 2015 1:48 PM

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Posted on Oct 5, 2015 3:31 PM

I haven't made any changes to settings... other than upgrading to El Capitan.

Sounds like a major change to me.


I can see all three drives in the finder but cannot connect to two of them. I've tried restarting the TC and computer and the other drives... but nothing changed.

You need to help spell this out.. like do you have three TC's or do you have a USB hub and two drives plugged into the TC or something else entirely. Drives plugged by USB into the Mac directly??


What drives don't work?? Have you tried manually mounting them??


You must get the drives working in finder first.


Then


I suggest you reset TM completely and start over. This will not delete the existing backups but you will need to rediscover them.


This is always the problem with network drives.. on the other hand if they are USB drives plugged directly into the computer I really want to hear about it.

5 replies
Question marked as Best reply

Oct 5, 2015 3:31 PM in response to steve fortier

I haven't made any changes to settings... other than upgrading to El Capitan.

Sounds like a major change to me.


I can see all three drives in the finder but cannot connect to two of them. I've tried restarting the TC and computer and the other drives... but nothing changed.

You need to help spell this out.. like do you have three TC's or do you have a USB hub and two drives plugged into the TC or something else entirely. Drives plugged by USB into the Mac directly??


What drives don't work?? Have you tried manually mounting them??


You must get the drives working in finder first.


Then


I suggest you reset TM completely and start over. This will not delete the existing backups but you will need to rediscover them.


This is always the problem with network drives.. on the other hand if they are USB drives plugged directly into the computer I really want to hear about it.

Oct 5, 2015 3:22 PM in response to steve fortier

Reply to LaPastenague: Sorry but your reply does not show here for some reason?


I have not made any changes to the time capsule settings.

I have two USB drives plus the Time Capsule which I switch between for backups. One of the USB drives is working for backups but I can no longer switch over to the Time Capsule or the other USB drive. All the drives show in the finder and also show in the TM preferences but it won't let me switch disks. I've tried unmounting/mounting them, I've done a hard reset on the Time Capsule but it's still giving me the same error message when I select it in TM preferences.


Thanks

Oct 5, 2015 3:45 PM in response to LaPastenague

I have not made any changes to the time capsule settings.

I have two USB drives plus the Time Capsule which I switch between for backups. One of the USB drives is working for backups but I can no longer switch over to the Time Capsule or the other USB drive. All the drives show in the finder and also show in the TM preferences but it won't let me switch disks. I've tried unmounting/mounting them, I've done a hard reset on the Time Capsule but it's still giving me the same error message when I select it in TM preferences.


Thanks

Oct 6, 2015 5:52 AM in response to steve fortier

Are the USB drives plugged into the computer or the TC?? This is important.


Reset the TC to factory and redo its setup. Then do the setup according to these instructions which are saying Yosemite but the same will apply to El Capitan.


Factory reset universal

Power off the TC.. ie pull the power cord or power off at the wall.. wait 10sec.. hold in the reset button.. be gentle.. power on again still holding in reset.. and keep holding it in for another 10sec. You may need some help as it is hard to both hold in reset and apply power. It will show success by rapidly blinking the front led. Release the reset.. and wait a couple of min for the TC to reset and come back with factory settings. If the front LED doesn’t blink rapidly you missed it and simply try again. The reset is fairly fragile in these.. press it so you feel it just click and no more.. I have seen people bend the lever or even break it. I use a toothpick as tool.

N.B. None of your files on the hard disk of the TC are deleted.. this simply clears out the router settings of the TC.


Setup the TC again.


Then redo the setup from the computer with Yosemite.

1. Use very short names.. NOT APPLE RECOMMENDED names. No spaces and pure alphanumerics.

eg TCgen5 for basestation and TCwifi wireless name.



If the issue is wireless use TC24ghz and TC5ghz with fixed channels as this also seems to help stop the nonsense. But this can be tried in the second round. ie plan on a first and second round of changes to fix this.. hopefully.. I will point out other steps that can be round2.


2. Use all passwords that also comply with 1. but can be a bit longer. ie 8-20 characters mixed case and numbers.. no non-alphanumerics.


3. If the TC is main router you can skip this point. This is only an issue when the TC is bridged.

Ensure the TC always takes the same IP address.. you will need to do this on the main router using dhcp reservation.. or a bit more complex setup using static IP in the TC. But this is important.. having IP drift all over the place when Yosemite cannot remember its own name for 5 min after a reboot makes for poor networking.


4. Check your share name on the computer is not changing.. make sure it also complies with the above.. short no spaces and pure alphanumeric.. but this change will mess up your TM backup.. so be prepared to do a new full backup. Sorry.. keep this one for second round if you want to avoid a new backup.


5. Mount the TC disk in the computer manually.


In Finder, Go, Connect to server from the top menu,

Type in SMB://192.168.0.254 (or whatever the TC ip is which you have now made static. As a router by default it is 10.0.1.1 and I encourage people to stick with that unless you know what you are doing).


You can use name.. SMB://TCgen5.local where you replace TCgen5 with your TC name.. local is the default domain of the TC and doesn't change.

However names are not so easy as IP address.. nor as reliable. At least not in Yosemite they aren't. The domain can also be an issue if you are not plugged or wireless directly to the TC.


6. Make sure IPv6 is set to link-local only in the computer. For example wireless open the network preferences, wireless and advanced / TCP/IP.. and fix the IPv6. to link-local only. Do the same for ethernet if you use it.

I have just clean installed El Cap.. and it gave me no issues at all.. I think clean install is always worthwhile.. I don't ever do upgrade installs now.. and I have therefore had almost no issues.


You can migrate your files and settings from the TM backup..


I also strongly recommend using a second different backup software.. I use Carbon Copy Cloner.. but Chronosync has a good reputation.


It is far superior when you are doing backups where you swap disks around.

Oct 6, 2015 6:05 AM in response to LaPastenague

I did the full Factory reset universal but it didn't work. I'm still getting the same error message, whether I try selecting it through TM or try "Connect As.." in the Finder. I shortened the name as indicated and followed through with the rest of the instructions. I tried connecting another spare USB drive to see if it will connect and no problem... unfortunately it's full.


Thanks

problem connecting to the server - server may not exist or unavailable. Check server name or IP address. Check network connection

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