How to make exact copy of volume with multiple partitions?

gpspad

macrumors 6502a
Original poster
Feb 4, 2014
587
19
I have an external USB 3 drive. It has 8 partitions, and I have CCC backup a mac to one of the partitions every day.

I'd like to make an exact copy of the disk, along with all of the partitions on it, so i can keep one copy off site.
 

Honza1

macrumors 6502
Nov 30, 2013
437
145
US
Two possibilities I know about, none completely painless.
1. If you can extract the drive from the external enclosure, you can get for like $30 disk duplicator (search Amazon for "disk duplicator"). It is cool device which serves as USB dock - and also can clone one disk to the other. And it does not need computer for that. You need same or larger size target disk and just push button, let it run, and after significant time it is done. Two exactly same clones, including partition-table. This duplicates bit-by-bit. Perfect when you need off site copy somewhere.
2. ddrescue - https://www.technibble.com/guide-using-ddrescue-recover-data/ I used this to clone failing disk to new drive. It also duplicates disk bit-by-bit, 1:1, and does not need the disks to be extracted. It is command line tool, not completely trivial to install (homebrew was my method) and not completely easy to use. In my case it run on 3TB disk for something like 2 days. But it was failing disk and I suspect it had challenge to read data in some places. Saved me from major data loss...
There are (hopefully) other, easier, methods. Even though, if you need to do this more than once, the disk duplicator/dock is very good option and not that expensive.
 
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gpspad

macrumors 6502a
Original poster
Feb 4, 2014
587
19
Thanks I hadn't thought of shucking the drive, its funny how complicated things have gotten just to have an offsite backup when you have multiple macs.

I have 4 macs on the home network. CCC works like a charm, every night CCC on each mac backups to one of the partitions. I have recovered and upgraded drives from these back-ups, I have no idea what windows users do w/o something like CCC. It works great in that area.

The one glaring issue, is that I also want to keep a backup off site. Ill look into those two options, but to keep it automated and to use CCC, I would have to unmount all the CCC backup drives. Shutoff the mac server.

Then attach the other external drive and restart the server, not exactly "hot swappable".
 

getrealbro

macrumors 6502
Sep 25, 2015
278
89
Why not periodically use CCC to clone the “local” backup partitions on the 1st USB drive, to a 2nd USB drive with “offsite” backup partitions.

GetRealBro
 

Honza1

macrumors 6502
Nov 30, 2013
437
145
US
The only ways how to painlessly create off-site backups I know about are:
1. On (e.g., business) notebook have one TM or CCC backup disk at one location (e.g., work) and at second location (e.g., home). This is obvious method and works only for systems which move routinely. It is kind of best as it costs nothing (well, the disks) and one can script it completely transparently for user.
2. Get some on-line storage and run CCC to backup there. These "network disks" have disadvantages - not bootable, slow, not completely secure, but they are really off-site and can be easily scripted. They usually cost monthly rental in sizes which we need. Also, they are not completely safe and reliable - companies are known to fail. And also, even big providers (Box, etc.), sometimes (though very rarely) loose users data...

I really do not know about other way to have off-site backup without "walking with a disk" involved ;-)
 

Fishrrman

macrumors P6
Feb 20, 2009
17,454
5,668
What I would do (I realize you aren't me):

1. Get the second drive.
2. Use Disk Utility to create 8 partitions on it that reflect the size of the 8 partitions on your source drive.
3. Use CCC to clone each partition from the source to the target.

Yes, this will take some time.
But it's all-but guaranteed to do the job right.
 

Honza1

macrumors 6502
Nov 30, 2013
437
145
US
The one glaring issue, is that I also want to keep a backup off site. Ill look into those two options, but to keep it automated and to use CCC, I would have to unmount all the CCC backup drives. Shutoff the mac server.
Well, depends what you mean here. Surely, you need to unmount the drive from the server which serves the partitions... But that is single piece of hardware and you need not to shut it off, just unmount the drive. And that can be done by script automatically at appropriate time or manually very easily.

But you do not need to dismount each partition from each client individually. CCC is smart - it WILL automount the target (and source also) drive when needed (if it is available) and it can dismount the drive when done with copying - simply select it as what to do after it is finished. I do that, so the CCC target disks are actually mounted ONLY when CCC is doing its scheduled backups. Users cannot accidentally write stuff to CCC drive this way.

Here is reasonable sequence of rotating two external (USB) disks - disk 1 and disk 2:
Server has Disk 1 mounted, and backups on clients run overnight... In the morning, unmount Disk 1 from server (or have it unmounted by script) and take Disk 1 with you.
Connect Disk 2 to server, it will auto mount to server - but clients will find it on their own ONLY when they are scheduled to do backups, mount each their own partition, do backup, unmount. By the morning all backups are done and partitions unmounted from each individual client. Unmount Disk 2 from server manually or by script, Take Disk 2 with you, attach Disk 1 and all is ready to repeat as needed. Switch between Disk 1 and Disk 2 on schedule you need.

Check CCC help for this. This really can be very easy and transparent for user.
 

gpspad

macrumors 6502a
Original poster
Feb 4, 2014
587
19
Thanks I will probably grab another external USB and try to rotate through them. The initial setup may a pain, but the mounting and un mounting is probably not as big a deal as I originally thought.

CCC seems to b able to do more than I give it credit for, Ill play around with it some more.