7 Replies Latest reply: Mar 11, 2011 6:12 AM by christopher gill
christopher gill Level 1 Level 1 (0 points)
I,m trying to securely erase (overwrite) my time capsule. The first overwrite took about 4 hours, the second is still running for more than 15 hours. Am I correct in assuming the first overwrite took only four hours because of less space that had been written on and now it's trying to erase the whole time capsule capacity 1TB and overwrite what I had not even used? This could take a month since I chose the most secure of 35 overwrites. What have I gotten myself into? Oh my!
christopher gill

i-mac, Mac OS X (10.6.6)
  • Bob Timmons Level 10 Level 10 (91,840 points)
    A secure erase replaces everything on the drive with "zeros". A 7 pass does this seven times and 35 pass does this 35 times.

    How "secure" does the disk really need to be?
  • christopher gill Level 1 Level 1 (0 points)
    I know what a secure erase does. The ? is why did the first pass take 4 hours and the second pass is still running at over 16 hours now. Did the first pass only overwrite the space "used" on the time capsule and the second pass is overwriting the whole time capsule?
  • Bob Timmons Level 10 Level 10 (91,840 points)
    The first secure erase or "zero out" puts zeros everywhere by overwriting what is there with zeros. Any blank space gets a new "zero" as well.

    Since everything is zeros after the first "zero out" pass, if you now select the 7 pass option, the entire drive will be zeroed out 7 more times. If you selected 7 pass originally, without first selecting the "zero out" option, then the drive is zeroed 7 times.

    If you selected 35 pass originally, without first doing the single "zero out", then the drive will be zeroed 35 times. If you did a "zero out" first, and then selected 35 pass, the drive will be zeroed a total of 36 times.

    Message was edited by: Bob Timmons
  • Bob Timmons Level 10 Level 10 (91,840 points)
    I'm still not clear on whether you did a single "zero out" first. If that's the case, 4 hours would be about right for a 1 TB drive.

    If you selected "7 Pass", you should expect about 7 times 4 hours = 28+ hours for the operation to complete.

    If you selected "35 Pass", then it's going to run 35 times 4 hours = 140 hours+ for the operation to complete.
  • christopher gill Level 1 Level 1 (0 points)
    I did not do a single zero pass first, I just went ahead and did a 35 pass first. Since the second pass is still running (now over 17 hours) this could take weeks! I think I have greatly over did this, oops!
  • christopher gill Level 1 Level 1 (0 points)
    I did not do a "zero out" pass first. Since it has now been almost 23hours that this erasure has been stuck on the 2nd pass and you estimated it would take about 28 hours for a seven pass erasure I think something else is wrong. I am leaving it running overnight to see if anything else progresses and if not I am calling apple tech support for help. They earlier suggested to unplug the time capsule and reset it. If you or anyone else has any more information on this it would be appreciated.
    thanks and good night, I'll check tomorrow morning for any new info.
  • christopher gill Level 1 Level 1 (0 points)
    Talked to apple tech phone support and we figured it was a problem with the time capsule itself, disk or electronic problem. Went to apple store exchanged for new time capsule, told it was a "fluke", they had never had a time capsule fail so soon after original purchase (Oct,11). Oh well.
    christopher gill