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[Solved] Trying to use CCC to clone to a Synology  



I'm getting a strange error trying to use CCC to clone to a new disk image on a Synology. The share has plenty of available space, credentials are correct, the share volume mounts just fine, and Time Machine backs up to it fine. But for some reason CCC gives the error, "The destination volume was not available when CCC attempted to run this backup task." Oddly enough, doing a google search for that exact error message reveals nothing. I feel like it should be something simple, but maybe it's trickier than I think? Something about connecting through AFP vs SMB, or using the [diskstation_name].local to connect vs. the IP address? 

Screen Shot 2019 01 30 at 10.20.44 AM
3 Answers

Not sure what you're saying, you want to clone your Mac's internal HD to a Volume on your NAS? or You're trying to clone your Internal HD to an image disk that you put on your NAS?

Either way you wouldn't be able to start from that clone from your mac in case you had problem with your internal hard drive. Best case would be to have a Clone, but not bootable but not sure you need all the system files if you can't boot from it. Just my 2 cents.:-)

@jefflambert670, yes I was trying to clone the internal drive to a disk image on the NAS. 

Interestingly enough, Mike Bombich replied as to the error:

Hi Ari,

This turns out to be a really subtle validation error. CCC attempts to mount the NAS volume, gets a result that indicates "It's already mounted", but then fails to validate the mounted NAS volume (i.e. it doesn't look like the same volume as the specified underlying NAS volume). Here's the difference:

01/31 02:44:00  Verifying that a volume with filesystem URL of "smb://time%20machine%[email protected]_smb._tcp.local/time%20machine" is present.
01/31 02:44:00  time machine is not present and mounted.
01/31 02:44:00  Device attached at //time%20machine%[email protected]_smb._tcp.local./time%20machine
Volume name:    time machine
Mount point:    /Volumes/time machine
Disk usage: 1.96 TB
Total size: 4.29 TB
Filesystem URL: smb://time%20machine%[email protected]_smb._tcp.local./time%20machine

Putting them side-by-side, the difference is barely noticeable:

smb://time%20machine%[email protected]_smb._tcp.local/time%20machine
smb://time%20machine%[email protected]_smb._tcp.local./time%20machine

The already-mounted instance of the sharepoint has a filesystem URL that includes a trailing ".". That character is legal, and occasionally present, although it's usually either consistently present or not present, I don't usually see a mix.

Ha, OK, now I see the issue. I thought I was already addressing this, indeed I already clean out other URL components that cause trouble. I was looking for a "trailing" period, though, and obviously it's not at the end of the URL, it's at the end of the hostname.

OK, fixed for 5.1.8. I have attached a build here if you'd like to verify the fix or use it in the interim. Thanks for the report!


Mike Bombich
Bombich Software, Inc.


Carbon Copy


wow, nice, Bombich are really efficient at tracking the issue for you! You still won't be able to boot from the clone, but I guess if you need it you'll have it.

@jefflambert670, I guess that brings to mind the question of best practices for a Synology. Perhaps TM backup to the NAS combined with a wired external HD for the clone is the ideal.


I've had a bad experience with a TM backup stored on a Synology. Probably not Synology's fault, but I was burned once, so no more. I have an external HD for my TM, and clone on four different partition of another external drive, once a week in rotation, so I have 4 clone, done at like clone1=week1, clone2=week2, clone3=week3, clone4=week4. I was doing a clone each night before, but also got burned with this strategy. I had trouble with my mac giving me all sorts of grief so told myself, hey, no problem, I've got a clone, AND a time machine backup. So, restored from my clone, which was from the last day. Well, the problem was on the clone too, so ended up having to start from scratch and formated the drive, thinking, I have my TM to go back to. So at about 3/4 of the way, there was an error on the TM drive and it got stuck. Nothing to do. 

I ended up having to reformat again, rebuild my mac from scratch and get some of the stuff from clone I keep at work but that was on the prior system. I didn't loose anything but time, but man that was scary. Hope my tale of woes will give you some perspective as to how to proceed with your backup strategies.