Article:		Automated Backups with Existing Tools
Subject:		Interesting Article
Date:		2004-03-24 13:31:04
From:		peterhickman
Response to: Interesting Article
There is a simpler solution that has the image file built up as it goes. hdiutil create -srcfolder $SOURCE -fs HFS+ -format UDRW -volname $VOLUMENAME $IMAGENAME This does not create a compressed image but avoids the whole 'create a blank image' thing. It makes the script shorter and more portable, however the whole backup process actually takes longer (1 hour 6 minutes versus 52 minutes for my 10 Gb backup). For small amounts of data, say 10 to 40 Gb, it doesn't take too long, up to 4 and a half hours. But when the amount of data gets passed 70 Gb it becomes the difference between 6 hours and nearly 8 hours. Did I really just say that 40 Gb was a small amount of data?

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• Re: There is a simpler solution
  2005-06-27 11:45:54  LHaim [Reply | View]
  
  
  Hello Peter,
  
  Thanks for posting your script ("origial" & "simpler"). I tried them both, and failed.
  
  First, "simpler": here's what happened after running the script (writing out to a FW external with 85GB free space; data is 41 GB)
  prompt> backupscript_simpler
  Initializing...
  Creating...
  Copying...
  .......
  Finishing...
  hdiutil: create failed - Bad file descriptor
  prompt>
  -----
  Next "original"
  
  prompt> backupscript_original
  (script crashed so ran line-by-line from shell)
  prompt> /bin/sh
  sh-2.05b# SOURCE='/'
  sh-2.05b# FILEDEST='/Volumes/MAXTOR_2/Mac_backups'
  sh-2.05b# VOLUMENAME=backup_`date +%Y-%m-%d`
  sh-2.05b# IMAGENAME=$FILEDEST/$VOLUMENAME.dmg
  sh-2.05b# SIZE=`df -m $SOURCE | grep '^/'`
  sh-2.05b# SIZE=`echo $SIZE | cut -d" " -f3`
  sh-2.05b# SIZE=`dc -e "$SIZE $SIZE 20 / + n"`
  sh-2.05b# hdiutil create -quiet -megabytes $SIZE -fs HFS+ -volname $VOLUMENAME $IMAGENAME
  sh-2.05b# DEVICE=`hdiutil attach $IMAGENAME | grep $VOLUMENAME | cut -d" " -f1`
  load_hdi: IOHDIXControllerArrivalCallback: timed out waiting for IOKit to finish matching.
  hdiutil: attach failed - No such file or directory
  sh-2.05b#
  ---
  Result: no backup.
  
  Any comments, observations, suggestions?
  
  Thanks!!!