Shirt Pocket Discussions  
    Home netTunes launchTunes SuperDuper! Buy Now Support Discussions About Shirt Pocket    

Go Back   Shirt Pocket Discussions > SuperDuper! > General

Reply
 
Thread Tools Rating: Thread Rating: 3 votes, 5.00 average. Display Modes
  #1  
Old 12-29-2006, 07:16 PM
caek caek is offline
Registered User
 
Join Date: Nov 2006
Posts: 12
Original and backup do not match

I've found a few files in a SuperDuper-generated backup that do not match the original. I haven't found an easy way to automate the checking of this (there's a lot of data), so I'm not sure how widespread across this problem is along the backup, but it certainly exists. I'm extremely concerned by this, as there are no errors in SuperDuper's log, and the Smart Copy completes successfully. The backup target is an encrypted, password-protected disk image on an external FW drive). There follows some Terminal output demonstrating this mismatch. I'd welcome any input. While I realise I can delete and regenerate the disk image, I'm reluctant to do so without establishing just what's gone wrong here.

Here's some examples of files which do not match:

otis:mike$ ls -al .aspell.conflrwxr-xr-x 1 mike mike 38 6 Nov 17:37 .aspell.conf -> Library/Preferences/cocoAspell/en.conf
otis:mike$ ls -al /Volumes/iBook\ Users\ Backup/Users/mike/.aspell.conf
lrwxr-xr-x 1 mike mike 38 29 Dec 21:29 /Volumes/iBook Users Backup/Users/mike/.aspell.conf -> Library/Preferences/cocoAspell/en.conf

(Note modification times differ. Not sure if this is a problem.)

otis:mike$ head .aspell.conf
# conf (string)
# main configuration file
# default: aspell.conf

# conf-dir (string)
# location of main configuration file
# default: <prefix:etc> = /usr/local/etc

# data-dir (string)
# location of language data files
otis:mike$ head /Volumes/iBook\ Users\ Backup/Users/mike/.aspell.conf
otis:mike$ [NO OUTPUT -- backup is a binary file!]
otis:mike$ diff .aspell.conf /Volumes/iBook\ Users\ Backup/Users/mike/.aspell.conf
Binary files .aspell.conf and /Volumes/iBook Users Backup/Users/mike/.aspell.conf differ


The backup of this directory of MP3s also does not match: files sizes an modification times match, but the content of all files (except, strangely, Track 6) differ, as shown by diff. Quicktime cannot open the files on the backup.

otis:mike$ ls -al /Users/Shared/Music/The\ Be\ Good\ Tanyas/Hello\ Love/
total 140200
drwxrwxrwx 16 mike wheel 544 21 Dec 01:40 .
drwxrwxrwx 7 mike wheel 238 11 Oct 16:33 ..
-rw-rw-rw- 1 mike wheel 6148 9 Dec 00:55 .DS_Store
-rw-r--r-- 1 mike wheel 5955712 9 Dec 00:57 01 Human Thing.mp3
-rw-r--r-- 1 mike wheel 6629504 9 Dec 00:57 02 For The Turnstiles.mp3
-rw-r--r-- 1 mike wheel 5197952 9 Dec 00:57 03 A Thousand Tiny Pieces.mp3
-rw-r--r-- 1 mike wheel 5130368 9 Dec 00:56 04 Ootischenia.mp3
-rw-r--r-- 1 mike wheel 4214912 9 Dec 00:57 05 A Little Blues.mp3
-rw-r--r-- 1 mike wheel 6807680 9 Dec 00:55 06 Scattered Leaves.mp3
-rw-r--r-- 1 mike wheel 6060160 9 Dec 00:57 07 Hello Love.mp3
-rw-r--r-- 1 mike wheel 5687424 9 Dec 00:57 08 Nobody Cares For Me.mp3
-rw-r--r-- 1 mike wheel 4532352 9 Dec 00:57 09 Out Of The Wilderness.mp3
-rw-r--r-- 1 mike wheel 5634176 9 Dec 00:57 10 Song For R..mp3
-rw-r--r-- 1 mike wheel 6578304 9 Dec 00:57 11 What Are They Doing In Heaven Today.mp3
-rw-r--r-- 1 mike wheel 3682432 9 Dec 00:55 12 Crow Waltz.mp3
-rw-r--r-- 1 mike wheel 5623936 9 Dec 00:44 13 When Doves Cry.mp3
otis:mike$ ls -al /Volumes/iBook\ Users\ Backup/Users/Shared/Music/The\ Be\ Good\ Tanyas/Hello\ Love/
total 140200
drwxrwxrwx 16 mike wheel 544 21 Dec 01:40 .
drwxrwxrwx 7 mike wheel 238 11 Oct 16:33 ..
-rw-rw-rw- 1 mike wheel 6148 9 Dec 00:55 .DS_Store
-rw-r--r-- 1 mike wheel 5955712 9 Dec 00:57 01 Human Thing.mp3
-rw-r--r-- 1 mike wheel 6629504 9 Dec 00:57 02 For The Turnstiles.mp3
-rw-r--r-- 1 mike wheel 5197952 9 Dec 00:57 03 A Thousand Tiny Pieces.mp3
-rw-r--r-- 1 mike wheel 5130368 9 Dec 00:56 04 Ootischenia.mp3
-rw-r--r-- 1 mike wheel 4214912 9 Dec 00:57 05 A Little Blues.mp3
-rw-r--r-- 1 mike wheel 6807680 9 Dec 00:55 06 Scattered Leaves.mp3
-rw-r--r-- 1 mike wheel 6060160 9 Dec 00:57 07 Hello Love.mp3
-rw-r--r-- 1 mike wheel 5687424 9 Dec 00:57 08 Nobody Cares For Me.mp3
-rw-r--r-- 1 mike wheel 4532352 9 Dec 00:57 09 Out Of The Wilderness.mp3
-rw-r--r-- 1 mike wheel 5634176 9 Dec 00:57 10 Song For R..mp3
-rw-r--r-- 1 mike wheel 6578304 9 Dec 00:57 11 What Are They Doing In Heaven Today.mp3
-rw-r--r-- 1 mike wheel 3682432 9 Dec 00:55 12 Crow Waltz.mp3
-rw-r--r-- 1 mike wheel 5623936 9 Dec 00:44 13 When Doves Cry.mp3
otis:mike$ diff /Users/Shared/Music/The\ Be\ Good\ Tanyas/Hello\ Love/ /Volumes/iBook\ Users\ Backup/Users/Shared/Music/The\ Be\ Good\ Tanyas/Hello\ Love/
Binary files /Users/Shared/Music/The Be Good Tanyas/Hello Love/01 Human Thing.mp3 and /Volumes/iBook Users Backup/Users/Shared/Music/The Be Good Tanyas/Hello Love/01 Human Thing.mp3 differ
Binary files /Users/Shared/Music/The Be Good Tanyas/Hello Love/02 For The Turnstiles.mp3 and /Volumes/iBook Users Backup/Users/Shared/Music/The Be Good Tanyas/Hello Love/02 For The Turnstiles.mp3 differ
Binary files /Users/Shared/Music/The Be Good Tanyas/Hello Love/03 A Thousand Tiny Pieces.mp3 and /Volumes/iBook Users Backup/Users/Shared/Music/The Be Good Tanyas/Hello Love/03 A Thousand Tiny Pieces.mp3 differ
Binary files /Users/Shared/Music/The Be Good Tanyas/Hello Love/04 Ootischenia.mp3 and /Volumes/iBook Users Backup/Users/Shared/Music/The Be Good Tanyas/Hello Love/04 Ootischenia.mp3 differ
Binary files /Users/Shared/Music/The Be Good Tanyas/Hello Love/05 A Little Blues.mp3 and /Volumes/iBook Users Backup/Users/Shared/Music/The Be Good Tanyas/Hello Love/05 A Little Blues.mp3 differ
Binary files /Users/Shared/Music/The Be Good Tanyas/Hello Love/07 Hello Love.mp3 and /Volumes/iBook Users Backup/Users/Shared/Music/The Be Good Tanyas/Hello Love/07 Hello Love.mp3 differ
Binary files /Users/Shared/Music/The Be Good Tanyas/Hello Love/08 Nobody Cares For Me.mp3 and /Volumes/iBook Users Backup/Users/Shared/Music/The Be Good Tanyas/Hello Love/08 Nobody Cares For Me.mp3 differ
Binary files /Users/Shared/Music/The Be Good Tanyas/Hello Love/09 Out Of The Wilderness.mp3 and /Volumes/iBook Users Backup/Users/Shared/Music/The Be Good Tanyas/Hello Love/09 Out Of The Wilderness.mp3 differ
Binary files /Users/Shared/Music/The Be Good Tanyas/Hello Love/10 Song For R..mp3 and /Volumes/iBook Users Backup/Users/Shared/Music/The Be Good Tanyas/Hello Love/10 Song For R..mp3 differ
Binary files /Users/Shared/Music/The Be Good Tanyas/Hello Love/11 What Are They Doing In Heaven Today.mp3 and /Volumes/iBook Users Backup/Users/Shared/Music/The Be Good Tanyas/Hello Love/11 What Are They Doing In Heaven Today.mp3 differ
Binary files /Users/Shared/Music/The Be Good Tanyas/Hello Love/12 Crow Waltz.mp3 and /Volumes/iBook Users Backup/Users/Shared/Music/The Be Good Tanyas/Hello Love/12 Crow Waltz.mp3 differ
Binary files /Users/Shared/Music/The Be Good Tanyas/Hello Love/13 When Doves Cry.mp3 and /Volumes/iBook Users Backup/Users/Shared/Music/The Be Good Tanyas/Hello Love/13 When Doves Cry.mp3 differ
Reply With Quote
  #2  
Old 12-29-2006, 07:19 PM
dnanian's Avatar
dnanian dnanian is offline
Administrator
 
Join Date: Apr 2001
Location: Weston, MA
Posts: 14,358
Send a message via AIM to dnanian
I can't explain this, since we're using a standard system call to copy the data over, and I've never seen a file get copied in a way that didn't generate an error.

Please use the "Send to shirt pocket" button to send me the set of logs from this backup: I'd like to take a look.
__________________
--Dave Nanian
Reply With Quote
  #3  
Old 12-29-2006, 10:09 PM
caek caek is offline
Registered User
 
Join Date: Nov 2006
Posts: 12
Quote:
Originally Posted by dnanian View Post
Please use the "Send to shirt pocket" button to send me the set of logs from this backup: I'd like to take a look.
Sent. Thanks for taking a look!
Reply With Quote
  #4  
Old 12-29-2006, 11:50 PM
trevyn trevyn is offline
Registered User
 
Join Date: Sep 2006
Posts: 10
That's funny, I just noticed something similar, with a text file.

The first 2.5k (exactly 2560 bytes) of the file was completely missing in the backup, and at the end, an extra 2560 bytes were appended. Most were null bytes, but in the middle of those was the spurious string "/Applications/SuperDuper!.app/Contents/Resources/Copy Scripts"

Figure that one out. Copy logs show nothing abnormal.

Now, the interesting part is that I kept that text file open in BBEdit for some time. Any changes were very minor, no large parts of text were moved around, etc.

So my theory is it may have something to do with files that are open when the copy is performed. If so, how can we address this? Corrupt backups are public enemy number one.

Another possibility: this drive has a small handful of unrecoverable IO errors; in order to get backups to succeed, I had to exclude four media files (unrelated to this text file) using a...yes...Copy Script. This text file has never had a problem for me in normal usage, but is it possible that the first 5 blocks were unreadable at some point, and when they became readable again, the data was never copied over? Kind of shooting in the dark here. Are the historical logs for scheduled backups kept past the last one?

Last edited by trevyn; 12-30-2006 at 12:02 AM.
Reply With Quote
  #5  
Old 12-30-2006, 12:05 AM
dnanian's Avatar
dnanian dnanian is offline
Administrator
 
Join Date: Apr 2001
Location: Weston, MA
Posts: 14,358
Send a message via AIM to dnanian
It's likely that the source file was damaged when we read it, but a subsequent write (which is typically done by writing a new file, deleting the old and renaming) was fine.

The actual file copy itself is done with a very well tested atomic OSX call that's relied upon by the entire system...
__________________
--Dave Nanian
Reply With Quote
  #6  
Old 12-30-2006, 12:10 AM
trevyn trevyn is offline
Registered User
 
Join Date: Sep 2006
Posts: 10
Quote:
Originally Posted by dnanian View Post
It's likely that the source file was damaged when we read it, but a subsequent write (which is typically done by writing a new file, deleting the old and renaming) was fine.

The actual file copy itself is done with a very well tested atomic OSX call that's relied upon by the entire system...
Maybe, but there's still a problem here in that a subsequent backup is not detecting the file as changed.

Also, I'm having trouble figuring out how "/Applications/SuperDuper!.app/Contents/Resources/Copy Scripts" could end up in any legitimate copy of the file, damaged or not.
Reply With Quote
  #7  
Old 12-30-2006, 12:08 AM
dnanian's Avatar
dnanian dnanian is offline
Administrator
 
Join Date: Apr 2001
Location: Weston, MA
Posts: 14,358
Send a message via AIM to dnanian
(Open files also shouldn't matter terribly, as long as they're not being actively written. I've done thousands upon thousands of test runs on this stuff, and these things don't happen unless there's some kind of underlying failure going on -- memory, unflagged disk errors, etc -- and it certainly sounds like that's the case in this situation.)
__________________
--Dave Nanian
Reply With Quote
  #8  
Old 12-30-2006, 09:13 PM
caek caek is offline
Registered User
 
Join Date: Nov 2006
Posts: 12
For those of you keeping score, Dave and I have been unable to figure out the exact reason how these files got into the state where their contents differ but the attributes that SuperDuper checks are the same. As a not entirely satisfactory solution, I've nuked the backup and created a new one.
Reply With Quote
Reply


Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)
 
Thread Tools
Display Modes Rate This Thread
Rate This Thread:

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
SuperDuper Failing on Backup - I/O Errors Stephen Kuhn General 1 08-13-2006 05:03 PM
Original OS & Backup won't boot (HUGE fan noise) super8trash General 9 02-26-2006 12:56 PM
How to verify a Scheduled Backup? tuqqer General 3 12-06-2005 07:50 PM
Why is my backup smaller than the original HD? uelef General 22 08-07-2005 07:48 PM
Backup und Original not identical? jfahrner General 6 08-02-2005 02:40 PM


All times are GMT -4. The time now is 12:20 AM.


Powered by vBulletin® Version 3.8.9
Copyright ©2000 - 2017, vBulletin Solutions, Inc.