[Zope] Copying Data.fs (was Re: Using XRon to backup my portal)

[Jens Vagelpohl]

FileStorage only appends at the end of the file. the only thing that 
could happen is bad records at the end of your copy. the ZODB code is 
already intelligent enough to shave that off all by itself.

why don't you just try and see how it works?

jens


On Sunday, Oct 27, 2002, at 19:51 US/Eastern, Ausum Studio wrote:

> Can anyone confirm it?
>
> I'd like to have a theoretical understanding of this subject besides 
> the
> practical one, because I suspect that there might come up byte-level
> inconsistencies at the copied file, not the original one, when a file 
> larger
> than the memory allocated for the application using it  is being 
> copied at
> the same it's been appended.
>
> I base my case on the idea that, as data need to be copied by chunks, 
> there
> would exist the possibility that not already copied data could have 
> changed
> during the copy of the first chunks, meaning that the final copied file
> would be different to the original one (at the time the copy started), 
> and
> not exactly equal to the same file at the time the copy ended.
>
> Thanks in advance,
>
>
> Ausum
>
>
>
> ----- Original Message -----
> From: "Jens Vagelpohl" <jens@zope.com>
> To: "Ausum Studio" <ausum_studio@hotmail.com>
>
>
>> i have never seen it that the original file is "frozen" during that
>> copy operation. i have successfully copied Data.fs files up to 5 GB 
>> (on
>> linux) without any indication that the website had any trouble. if you
>> can verify that the original turns "read-only" during the copy then
>> that could be a windoze-only thing.
>>
>> jens
>>
>>
>> On Sunday, Oct 27, 2002, at 01:05 US/Eastern, Ausum Studio wrote:
>>
>>> Just a quick question about it:
>>>
>>> What happens to the ongoing transactions? I'm using W2K and from 
>>> other
>>> large-file copies I've done it looks like the original file is frozen
>>> to
>>> changes, unless it's completely uploaded in memory.
>>>
>>> Do I need to stop Zope in order to allow the OS to perform the copy?
>>>
>>> Thanks in advance,
>>>
>>
>>
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