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Bootable Duplicate


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I am using Retrospect Desktop for Macintosh, Version 6.0.204, with OS 10.3.9.

 

I periodically make a DUPLICATE of my hard drive on a partition on an EXTERNAL hard drive. The duplicate I make is with "REPLACE CORRESPONDING FILES".

 

Until recently, that duplicate has been a BOOTABLE version. The last 2 times I made the duplicate it has NOT BEEN BOOTABLE.

 

As far as I know, I did not change anything.

 

Any ideas as to why that duplicate is no longer bootable??

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Dave,

 

I chose it to reduce the time and size of subsequent updates to the duplicate.

 

I believe that I have always used this option and it has booted until now.

 

Do you think I should make a duplicate by replacing all, to start from scratch, and see if that is bootable?

 

Ed

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I'd suggest that the first thing you do is familiarize yourself with the difference between "Replace Corresponding Files" and "Replace Entire Disk," which can be found in the User's Guide starting on page 58. Their differences are not related to speed of execution.

 

In general, if the volume being used as the Destination is _only_ being used for this (and is not being used to store other files, etc) you should use the "Entire Disk" option.

 

That being said, you provide no other information about the state of the completed Duplicate. For example, does it show in the Startup Disk Preference Pane as a valid boot volume? What happens when you try and boot from it?

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Dave,

 

You asked: For example, does it show in the Startup Disk Preference Pane as a valid boot volume? What happens when you try and boot from it?

 

Yes, it is shown as a boot volume. When I restart, selecting it as the startup disk, the startup begins with the Apple logo, then a rotating spiked wheel is added (as usual), and then a circle with a diagonal slash appears instead of the Apple icon. The spoked wheel then goes on "forever" until I finally force a shutdown by depressing the On button for a number of seconds. This never happened previously.

 

NEW DATA.... I WENT BACK TO TRY IT AGAIN, AND IT NOW WORKS! NO CIRCLE WITH DIAGONAL SLASH AND IT BOOTS FROM THE EXTERNAL HARD DISC. GO FIGURE!! I have no idea what is going on.

 

I really appreciate your trying to help. Thanks,

 

Ed

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I suspect that there was some missing or corrupted file on the destination disk that was fixed with a try to "replace entire disk". Subsequent updates to update changed files worked because this problem had been fixed.

 

As a comment, Retrospect is really not the right tool to do what you are doing; it's the right tool for backups, but you aren't doing a backup, but instead addressing availability issues.

 

A better tool for what you are doing would be something like a RAID 1 mirror split (see the SoftRAID.com site for a good discussion and white papers), which is the only way to get an instantaneous image of a disk, or the freeware SuperDuper!, which will do what you are trying to do, better. The shareware upgrade to SuperDuper! has more options that might suit your needs, too.

 

Russ

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  • 11 months later...

Quote:

 

As a comment, Retrospect is really not the right tool to do what you are doing; it's the right tool for backups, but you aren't doing a backup, but instead addressing availability issues.

 

A better tool for what you are doing would be something like a RAID 1 mirror split (see the SoftRAID.com site for a good discussion and white papers), which is the only way to get an instantaneous image of a disk, or the freeware SuperDuper!, which will do what you are trying to do, better. The shareware upgrade to SuperDuper! has more options that might suit your needs, too.

 

Russ

 


 

Russ (or anyone),

 

I just found this thread because I'm considering making a bootable duplicate. Why is Retrospect not the right tool to do this, say as compared with SuperDuper?

 

Ken

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Quote:

I just found this thread because I'm considering making a bootable duplicate. Why is Retrospect not the right tool to do this, say as compared with SuperDuper?

 


Several reasons. First, if you don't have an ACL-enabled drive, Retrospect restore (not duplicate) can create a bootable drive. Been there, done that, and it has worked for years (well, at least since 1992). However, Leopard enables ACLs, so you will not end up with all metadata in that case.

 

Second, Retrospect was designed to do backup/restore, not duplicates. It's slow, but it can copy (duplicate) files correctly (ignoring the metadata issue).

 

I know of only three ways to do bootable disks that preserve all metadata.

(1) ASR (which can be forced into block mode, if you read the manual carefully - this is what Apple's Disk Utility uses under the hood)

(2) SuperDuper! (free)

(3) RAID 1 mirror split.

 

We use #3 on our server because it's the only way you can replicate a server with almost zero down time. RAID 1 rebuilds in the background, then shut down mail services (because otherwise you get a cyrus database inconsistency), split the mirror, bring mail services back up.

 

But I have used SuperDuper! as well. I have heard that CCC 3.0 (not 2.x), just released, does preserve all metadata, but I haven't tested that.

 

It's not an unsolvable issue. I understand that Retrospect for Mac is undergoing a ground-zero rewrite. I remain optimistic, but will still test thoroughly before deployment into production.

 

Making a bootable drive is not trivial. It's more than just copying files.

 

Russ

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Quote:

 

Several reasons. First, if you don't have an ACL-enabled drive, Retrospect restore (not duplicate) can create a bootable drive. Been there, done that, and it has worked for years (well, at least since 1992). However, Leopard enables ACLs, so you will not end up with all metadata in that case.

 

Second, Retrospect was designed to do backup/restore, not duplicates. It's slow, but it can copy (duplicate) files correctly (ignoring the metadata issue).

 

I know of only three ways to do bootable disks that preserve all metadata.

(1) ASR (which can be forced into block mode, if you read the manual carefully - this is what Apple's Disk Utility uses under the hood)

(2) SuperDuper! (free)

(3) RAID 1 mirror split.

 

Russ

 


 

Russ, thanks. I'm running the last version of Tiger - does that mean I don't have an ACL-enabled drive?

 

Sounds like Disk Utility or SuperDuper! is the way to go. Since I'll have to use Restore in Disk Utility with either one, is there really any difference in the output?

 

Ken

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Quote:

Retrospect was designed to do backup/restore, not duplicates...

 


 

This simply not true!

 

Retrospect, as we know it today, was designed for "Classic" style Mac OS; sometime around System 5 or 6 (I don't have the exact dates handy to cross reference, but it was a while ago).

 

At that time, Duplicate was certainly a design goal, and one that was well implemented for its time. Permissions, as seen by AppleShare, Personal File Sharing and AppleShareIP were preserved. There really was no substitute (that I remember) for this feature.

 

With OS X, many *nix tools were available right away for copying files. "cp" worked in 10.0, if you didn't care about Type/Creator, resource forks or other metadata. Then CpMac was provided to developers, then ditto with the -rsrcFork flag, and now ditto copies metadata, extended attributes and Access Control Lists unless you tell it not to.

 

Even with it's limitations, Retrospect's Duplicate has features other programs do not. IIRC, other programs cannot show you a list of the files that it will copy, nor allow you to modify that list on a file by file basis. IIRC, other programs do not, after the fact, compare the files that it copied against the files that it was slated to copy.

 

The whole "closing" thing sucks. And it would be less frightening if files were deleted one by one, just before the new version was copied over, instead of in bulk at the beginning of the Execution. But Duplicates have always worked for me when I have done them.

 

Dave

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I read and re-read the User's Guide section beginning on page 58 and I'm still at a loss to understand the difference between the two options.

 

Quote:

Replace Entire Disk replaces the entire contents of the destination volume with the selected files and folders from the source volume. Identical files already present on the destination are not duplicated.

 

Replace Corresponding Files overwrites any matching files existing on the destination volume that correspond to the selected files on the source, even if the destination files are newer. Retrospect leaves files untouched if their names and locations do not correspond to those files marked for duplication.

 


 

My objective is to have instantly bootable clones of what's on my OS 10.5.1 hard drive on external hard drives with at least one drive always stored at a remote location.

 

1. For that purpose, which option is recommended?

 

2. How much faster or slower is Retrospect (6.1.126) Duplicate than SuperDuper or Carbon Copy Cloner if one chooses not to run Duplicate's Compare process?

 

Respectfully, Norm

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Replace entire disk deletes files from the destination that no longer exist on the source volume making the 2 identical. You use this option to make identical copies of the source drive.

 

replace corresponding does not delete files from the destination that have been deleted from the source.

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Quote:

Sounds like Disk Utility or SuperDuper! is the way to go. Since I'll have to use Restore in Disk Utility with either one, is there really any difference in the output?

 


Note that ASR became broken in MacOS 10.4.6 and later; worked in 10.4.5, now doesn't preserve some metadata. SuperDuper! has always worked. CCC 3.0 may be fixed.

 

Quote:

I'm running the last version of Tiger - does that mean I don't have an ACL-enabled drive?

 


No. MacOS 10.4.x Server has ACLs enabled by default on the boot drive. MacOS 10.4.x non-server supports ACLs but does not have ACLs enabled by default on the boot drive (but they can be turned on with some effort).

 

Quote:

I have used Retrospect under leopard to make bootable duplicates many times. It works 100% of the time for me.

 


I'm really not trying to argue with people here. Just because the drive is "bootable" does not mean that it's the same as the source drive. As an extreme example (but not the issue, and not to imply that Retrospect does so because it doesn't), I could create a "bootable" drive with all users and all user home directories deleted, and with all added non-Apple applications and configurations (preferences) for those applications deleted. In other words, a MacOS clean install DVD creates a "bootable" drive, but that bootable drive is very different from what you may have had before.

 

To me, the question is more whether your "bootable" system volume has all of the same characteristics (UIDs, permissions, metadata, etc.) as the source volume. See, e.g.:

http://tinyurl.com/qt83g

(but note that the blog author has some personal issues with Retrospect; modification dates ARE preserved by Retrospect if you do the restore properly (by entire disk), contrary to what is reported).

 

And, as I implied, it's more difficult than just copying files and metadata. Some files (e.g., OS caches) should not be replicated. Mike Bombich's web site (http://bombich.com) has a good discussion (Mike is an Apple engineer).

 

Again, I wasn't trying to argue here, just to raise the various issues. And I have used Retrospect to make bootable disks from backups after a failure, but it's not the course of action that I prefer.

 

Russ

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Quote:

 

I'm really not trying to argue with people here. Just because the drive is "bootable" does not mean that it's the same as the source drive. As an extreme example (but not the issue, and not to imply that Retrospect does so because it doesn't), I could create a "bootable" drive with all users and all user home directories deleted, and with all added non-Apple applications and configurations (preferences) for those applications deleted. In other words, a MacOS clean install DVD creates a "bootable" drive, but that bootable drive is very different from what you may have had before.

 

To me, the question is more whether your "bootable" system volume has all of the same characteristics (UIDs, permissions, metadata, etc.) as the source volume.

 

Russ

 


 

And that's exactly what I want to do: clone this drive, erase it, and restore it with the clone.

 

Ken

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Quote:

And that's exactly what I want to do: clone this drive, erase it, and restore it with the clone.

 


Then I suggest you use SuperDuper! (unless you have Leopard, in which case you have to wait for the Leopard version to be released) or give Mike Bombich's Carbon Copy Cloner 3.0 a try (it's supposed to work on Leopard - I haven't tried because we use the RAID 1 mirror split trick).

 

Russ

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And that's exactly what I want to do: clone this drive, erase it, and restore it with the clone.

 


 

First off, if you are going to intentionally erase data, it would be _very_ wise to have multiple backups in place before you do. Even after successfully and accurately duplicating your drive to another, the moment you erase that first drive Murphy's Law states that your cloned drive will spontaneously explode.

 

Once your data is safe, your best options for creating an accurate duplicate version will be possible while your original source volume is _not_ running your computer. Booting from an entirely different volume is the safest, and possibly only, way to assure that you're getting an accurate copy. This would be true no matter what software tools you use (other then the split RAID 1 mirror technique that Russ has recommended on this Forum (which requires a particular hardware configuration)), including Retrospect.

 

Using Apple's tools, you can boot from your OS X install DVD, and use Disk Utility's Restore function. Set your startup disk as Source, and your clone disk as Destination, and make sure to check the "erase destination" box (even if the destination volume is already empty).

 

This will give you a block-by-block copy of everything, with all unix and metadata intact.

 

Of course, this is not a very good "backup" solution per se, as it's not the sort of thing a user is going to do every day.

 

You don't describe why you want to erase your current drive and then restore it with the same bits that it had before, but this would be one way to do it.

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Quote:

 

 

First off, if you are going to intentionally erase data, it would be _very_ wise to have multiple backups in place before you do. Even after successfully and accurately duplicating your drive to another, the moment you erase that first drive Murphy's Law states that your cloned drive will spontaneously explode.

 

Once your data is safe, your best options for creating an accurate duplicate version will be possible while your original source volume is _not_ running your computer. Booting from an entirely different volume is the safest, and possibly only, way to assure that you're getting an accurate copy. This would be true no matter what software tools you use (other then the split RAID 1 mirror technique that Russ has recommended on this Forum (which requires a particular hardware configuration)), including Retrospect.

 

Using Apple's tools, you can boot from your OS X install DVD, and use Disk Utility's Restore function. Set your startup disk as Source, and your clone disk as Destination, and make sure to check the "erase destination" box (even if the destination volume is already empty).

 

This will give you a block-by-block copy of everything, with all unix and metadata intact.

 

Of course, this is not a very good "backup" solution per se, as it's not the sort of thing a user is going to do every day.

 

You don't describe why you want to erase your current drive and then restore it with the same bits that it had before, but this would be one way to do it.

 


 

Dave, well I managed to do some things right, and so far, it seems OK.

 

I did this so that I could partition the drive with Disk Utility. I had created a sparse image earlier (across a network) on the entire volume with SD, and since I didn't know it would be better to not have the source disk running, it was, but all the apps were shut down. I also made a second backup - a Duplicate using Restrospect (Replace Entire DisK) - just in case. I booted from another drive connected to the Mac, mounted the sparse image, and ran Restore (with Erase checked). I watched the status bar and it said, "Copying blocks..." Afterwards the new parition mounted OK, but I had a few minor anomalies: the first time I tried to access System Prefs from the Apple menu, nothing happened. I opened it from Recent Items, and then it was fine. Same with Software Updates. I had to open it from System Prefs and do a Check now, then it works from the Apple Menu. I've played around with other things, and so far it seems OK.

 

Ken

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