Any way to speed up how slow Carbon Copy Cloner's evaluation feature is?

[GimmeDatApple]

I've been having issues copying 2TB of files from an internal file storage SSD to a new external one on my iMac. No matter what I tried in Finder I was getting error -36 after about 40 minutes of copying, somewhere around the 1.5 TB mark. Yes I tried the dot_clean and chmod 755 commands on the drive, but nothing was working.

I downloaded a trial of CCC and set a restore from the internal SSD to the external one connected via Thunderbolt 3/USB-C. Now the copy time has jumped from 55-ish minutes to over 6 1/2 hours. Both drives are high performance drives and a copy from the internal SATA bus (Samsung EVO 870) to the external TB3 bus (Western Digital Blue) should be fairly quick. It seems that the bottleneck is the 'evaluation' function.

I read CCC's performance problems page and didn't see anything about why evaluation would be so slow. Any thoughts?

 

[HobeSoundDarryl]

If the files are as a whole collection in a folder or folder of folders of files, etc and this is a first backup, cut CCC out of the equation and just manually drag and drop the folder(s) onto the external drive. Let that complete and then use CCC to compare what are now two duplicates of stored files. Next time you add files to one, CCC can then focus only on synching the new files to the other. Instead of 2TB, perhaps that will be a much smaller amount of files?

Bonus: this option may also be a little faster than having CCC copy "all" for the first time. But don't expect incredible speed as that's a lot of storage to push through whatever kind of connection your are using.

My guess is that some file in the 2TB might be corrupted and CCC is choking on that file. A non-CCC copy may also choke on it. It looks like these may be numbered photo files. So let it process and if it gets to a point where it also chokes, eyeball the list to see which file was last attempted/completed, then open it to see if it opens and then open th next one to see if it will open. If not, dump the bad file and all will probably be OK for the remaining 500GB.

If that doesn't do it but the corrupt file still seems plausible, copy blocks of files at a time until you find the block that has a block of files that kills the transfer. Then copy a chunk of that block at a time until you find the chunk that has the bad file. And keep copying fewer and few files until you find the bad one.

One more guess: is the external drive OK? You might want to run Disk Utility, First Aid on it and see if it says all is OK. Do you have > 1.5TB of free space on that disc?

 

[GimmeDatApple]

If the files are as a whole collection in a folder or folder of folders of files, etc and this is a first backup, cut CCC out of the equation and just manually drag and drop the folder(s) onto the external drive. Let that complete and then use CCC to compare what are now two duplicates of stored files. Next time you add files to one, CCC can then focus only on synching the new files to the other. Instead of 2TB, perhaps that will be a much smaller amount of files?

Bonus: this option may also be a little faster than having CCC copy "all" for the first time. But don't expect incredible speed as that's a lot of storage to push through whatever kind of connection your are using.

My guess is that some file in the 2TB might be corrupted and CCC is choking on that file. A non-CCC copy may also choke on it. It looks like these may be numbered photo files. So let it process and if it gets to a point where it also chokes, eyeball the list to see which file was last attempted/completed, then open it to see if it opens and then open th next one to see if it will open. If not, dump the bad file and all will probably be OK for the remaining 500GB.

If that doesn't do it but the corrupt file still seems plausible, copy blocks of files at a time until you find the block that has a block of files that kills the transfer. Then copy a chunk of that block at a time until you find the chunk that has the bad file. And keep copying fewer and few files until you find the bad one.

One more guess: is the external drive OK? You might want to run Disk Utility, First Aid on it and see if it says all is OK. Do you have > 1.5TB of free space on that disc?

Unfortunately this will not work. I will get error -36 at some point during the copy process when I attempt to drag the folders onto the new drive.

I booted into recovery mode and ran First Aid on all volumes, no errors at all.

 

[HobeSoundDarryl]

Then, I suggest you copy them in small batches so you can narrow in on the bad file(s). For example, if you have 3000 files in total, copy 200 at a time over until it fails. That would imply the bad file in that last batch of 200. So then copy 100 of the 200. If it makes it, try 50 of the other 100. And keep going this way until you find what is probably as little as one bad file. Delete the bad file and the rest will probably copy.

Basically, you are doing process of elimination, narrowing more and more in on what is probably one file that is corrupt.

 

[Fishrrman]

If it was me, I'd completely erase the target drive, and start over fresh.

I don't know if this still applies, but...
CCC used to have a feature that -- if it encountered one or more corrupted files during a backup -- it would not "quit" like the finder. Instead, CCC would keep going by "passing over" the bad files while copying all the GOOD files. The problem file(s) would be identified in a log so that the user could decide what to do with them.

Again, I don't know if this still is a part of CCC.

 

[eyoungren]

Do you have safety net on? Try turning it off.