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Jeff,

I was curious if you could elaborate further on your initial post:

  "With digital audio tape the error only affects that portion of the
recording"

Which format of digital audio tape are you referring to?  R-DAT/
DASH/ PD?

Were you stating that you prefer digital audio tape formats to
Enterprise-class data storage tapes?

John
John Spencer
www.bridgemediasolutions.com


On Jun 9, 2005, at 4:52 PM, Jeffrey Kane wrote:

> I don't believe I explained myself properly. Most backup
> applications will
> skip a bad block (or even several blocks) of data and continue the
> restore.
> What I describe arises when the corruption exceeds the ability of the
> software to recover from errors. In that case, an entire file (or
> several if
> not the whole tape depending on the location of the error) will be
> rendered
> unrecoverable. The validation of the archive/backup at the time
> only ensures
> the initial process succeded. The problematic variable is between
> archival
> and retrieval. With digital audio recordings, such errors will only
> render
> that portion of the recording unrecoverable.
>
> As for error correction, that is a function of the format (AIT/LTO/
> DLT/etc)
> and software used for backup/archival. On 'trusting' a datatape to be
> readable 25-30 years from now; I completely agree. That is the
> figure I
> recall being used when discussing longevity. In my case, I re-archive
> critical material every three years. Data on tape IMO is far too
> susceptible
> to corruption to be relied upon for a longer timeframe than that.
>
> Jeff
>
>
>> -----Original Message-----
>> From: Association for Recorded Sound Discussion List
>> [mailto:[log in to unmask]] On Behalf Of John Spencer
>> Sent: Thursday, June 09, 2005 2:47 PM
>> To: [log in to unmask]
>> Subject: Re: [ARSCLIST] Longevity of data tape?--
>>
>> This is an incorrect statement.  There are various backup
>> applications that will skip a bad block of data and continue
>> the restore process, as well as applications that will report
>> on the quality of the data archive as it is being written.
>> Error correction is not a function of the data storage tape itself.
>>
>> And I would never trust a data storage tape to be readable
>> 25-30 years from now.
>>
>> John
>> John Spencer
>> www.bridgemediasolutions.com
>>
>>
>> On Jun 9, 2005, at 2:36 PM, Jeffrey Kane wrote:
>>
>>
>>> I've seen the figure 25-30 years bandied about for data tape. Data
>>> backups are a double edge sword. They have better error
>>>
>> correction so
>>
>>> the data is more resilient. However, if there's an
>>>
>> unrecoverable error
>>
>>> it renders ALL data for that particular file (and if it's in the
>>> directory area, all data on the tape) unrecoverable. With digital
>>> audio tape the error only affects that portion of the recording.
>>>
>>>
>>
>>
>
>