TM backup: can I use two drives to back up data on two other drives?

somanna wrote:

. . .

I guess that one should dedicate the back up volume and take care to ensure that you have no other important data on that volume;

Yes, it's always best to dedicate a drive (or partition) to backups, whether they're made with Time Machine or another app. Placing anything else there may not cause a problem, but you'll only have one copy of it.

Is this the correct interpretation?

Yup.

somanna wrote:

I guess that Russ is saying that having a clone of one's data causes confusion in FCPX since the file names in the clone/clones remain the same. By making a duplicate of the data, FCPX is less stressed. The event manager is a useful software which allows one to easily hide/unhide events and projects.

Sounds reasonable, but as I don't use FCPX, I don't really know.

I have some data on the 'b' drive which I do not have on my 'c' drive and also vice versa. In this state of affairs, how can I get CCC to ensure that both of these drives are filled up with the same data?

You can do that with CCC, but you have to be careful:

The Handling of data already on the destination pop-up opn the right of the setup window is what you need. You'll want to select Preserve newer files, don't delete anything. See the explanation on the setup page when you select that option.

Clone "b" to "c" with that setting; that will get everything that was on "b" to "c".

Then clone "c" to "b" also with that setting; everything on "c" will now be on "b" as well.

Thereafter, if "b" is your "Master" or original copy, you'll probably only want to clone "b" to "c", and change the setting to Delete anything that doesn't exist on the source. That way, "c" will always be an exact copy of "b".

I don't know just how you work with the data on "b", but you might want to select Temporarily archive modified and deleted items to keep copies, for a while, on "c" of things that were changed or deleted on "b" since the last backup.

somanna wrote:

. . .

I have yet to get started using CCC and hence I presume that this option of selecting 'Temporarily archive modified and deleted items' would be given when setting up this as a scheduled task[...need further guidance of how to get this tasking done].

You'll see that pop-up on the main window.

There's also a Schedule this task.. button at the bottom. Once a task is defined on the main window, you can click that button to set up a schedule for it (if you want). Once set up, you can access it from the menubar:

But the best way to get familiar with it is to start using it. You have some drives/partitions you can experiment with, so give it a try.

Another question on my mind [oozed out when reading the documentation] is this: do I have need, in my present planned workflow, to have a 'small volume' to have a 'clean install' of my Mac's OS from which to boot up should the internal HD fail?

You already have a Recovery HD. See Using the Recovery HD. Start up from it and poke around, just to get familiar with it.

Once you've cloned your internal HD, you can start up from that if necessary. It will run your Mac just like the internal HD (only somewhat more slowly).

When you do your first Time Machine backup of the internal HD, Time Machine will copy the Recovery HD to the TM drive, so you can start up from it, too.

Some "power users" (or folks who think they are) make one or more drives or partitions with various things on them, such as a "stripped down" copy of their OSX volume, various repair utilities, etc. I doubt you need anything more than the Recovery HDs and a clone of your OSX drive.

somanna wrote:

. . .

As I have learnt from this thread that one ought to specifically have GUID as the partition map scheme, I am puzzled to see that my thunderbolt is having a different partition scheme! Anyway, I am going to erase this thunderbolt and begin using it fo videoediting. For videoediting use, what should be the partition scheme may I ask?

It probably doesn't matter for that purpose, but as long as you're going to erase it, you might as well reformat it and use the GUID partition map.

APM was used for older Macs. When Apple started using Intel Macs, they switched to GUID. For most purposes, GUID is preferred but either will work. However, you should use GUID for an OSX partition or a Time Machine drive.

(Sorry, I saw the original part of this post via the e-mail notice -- since I didn't need to respond, I didn't come to the actual thread, so missed the addition.)

somanna wrote:

. . .

I want to partition my brand new 2 TB EHD [the 'e' drive in my table above] into 2 equal sized partitions. I want to have a clone backup of my internal HD on one and personal data [principally my e-Sword bible, which I can always replace should there be any drive failure] upon the other.

My question is this: should I select the top partition [where you said [?] the data enters] as the destination for the backup or the bottom partition?

It doesn't really matter, but I'd recommend using the first (top) one for your Time Machine backups.

The reason is, if you ever need to enalrge it, it's much easier to do if it's the top one.

somanna wrote:

. . .

Does this mean that the TM backup which was created having the thunderbolt under as APM has been an exercise in futility?

Do you mean the TM drive has APM? If so, it will work fine, with one exception: Time Machine can't copy the Recovery HD to it, so you won't be able to boot into Recovery from it. But you'll have the "bootable clone" on another drive, and since you'll be using CCC, you can use CCC to copy the Recovery HD from your internal HD to the CCC clone. Don't worry about that now; if and when you want to do that, select Window > Disk Center from the CCC menubar.

But if you haven't started using the TM drive, it will only take a few minutes to reformat it with GUID.

Now I am on the verge of reformatting [erasing] this thunderbolt and use it for videoediting in FCPX as before. Should I then choose GUID as the partition scheme?

GUID is always preferred with an Intel Mac. APM would work, but there's no advantage to it.

Message was edited by: Pondini

somanna wrote:

. . .

I plan [you are aware of it and have consented that it ia workable] to have 2 partitions of the 3 TB Seagate, one to be used as TM backup of my Mac's IHD and the other one to be as a clone destination of my thunderbolt [videoediting drive]. In this scenario, which is the partition [upper or lower] on which I should have the destination of my thunderbolt's clone?

Wait . . . I misunderstood your earlier post, sorry. 😟

You were talking about the (e) drive, and I looked at the chart that said it was the Time Machine backup of your internal, but I didn't notice that your post said it would be the CCC clone. I'd still be inclined to put that one first, but it really doesn't make much difference.

Now, the 3 TB drive (d) will have your Time Machine backups. In that case, I'd recommend putting them on the first (top) partition, for the same reason -- if you ever want to expand it, it will be much easier if it's the first one on the drive.

FYI, I would consider the video backup being done to be of greater importance since I would be a having a secondary backup of the IHD elsewhere. Thinking of having 2 TB space for the thunderbolt backup. Planning to keep this thunderbolt backup partition at the top. What do you counsel?

I'd put the TM drive at the top, as noted above. Just in case you ever want to expand it.

The upper partition will be slightly faster than the lower one (the outside of the disk spins faster). But since it's on a (slow) USB connection, it won't make any difference. If it were FireWire 800, you might notice a difference.

Again, don't get too "hung up" on the exact setup. As you use it, you'll probably think of ways that will accommodate your workflow better, or you may replace a drive, or something else may change, and you may want to adjust accordingly.

somanna wrote:

. . .

Pondini, the 2 TB Seagate would be having 2 partitions and I said that I would be using one partition to have a clone [CCC] of my IHD on it and not time machine.

Yes, I was composing my reply to your earlier post and hadn't seen this one yet.

On further thought, I think it is better to have a 1250 GB partition on the top for having a clone backup of my IHD and a lower partition of 750 GB for personal data. The drive would be having GUID scheme. How does this sound to you?.

Yes, that would be fine -- the other way would be fine, too. Whatever you're comfortable with.

But . . . why do you want a 1250 GB partition for a clone of your 500 GB internal HD?

A Time Machine partition should be much larger than the data it's backing-up, but a clone (without archiving) only needs to be the same size. If you're going to use CCC's archiving, it should be somewhat larger, but probably not a great deal. Depends, of couse, on how much you change and how long you want to keep the archives.