[Samba] Samba and Preallocated Files

AndyLiebman at aol.com AndyLiebman at aol.com
Tue Mar 15 23:13:17 GMT 2005

In a message dated 3/15/2005 1:00:38 P.M. Eastern Standard Time,  
jra at samba.org writes:

On Tue,  Mar 15, 2005 at 06:31:19AM -0500, AndyLiebman at aol.com wrote:
> A  question about capturing videos to a Samba  share... 
>  When Apple's Final Cut Pro captures video files, it  pre-allocates file  
> on the destination volume. 
> If you capture to  a  local volume that's physically attached to a 
> or if  you capture to a  network volume via AFP (Apple File Sharing 
> you can see that Final Cut  instantly creates a file of the  anticipated 
> on the destination volume at  the moment just  before capture begins (the 
> anticipated size is based on the   maximum capture time limit set by a 
> However, when  capturing  videos to a Windows or Samba share, Final Cut 
>  actually will write out "dummy  data" to a file, and then presumably it  
replaces the 
> dummy data with real data  as the capture moves  along. 
> Effectively, this makes Samba and Windows   shares useless for capturing 
> Cut videos. Because, for instance,  if you  expect to capture a 20-minute 
> clip, it will take  approximately 10 minutes to  create the pre-allocated 
>  before capturing even begins -- even when you are  connecting via a  
> Gigabit Ethernet link. The process seems to chug   along unbelievably 
> And if you were capturing uncompressed  video (which  has about 5x the data 
> of DV video) well, the  wait would be interminable.  
> Can anybody on this list  see a way to allow Final Cut to instantly  create 
> that pre  allocated file space that it wants to create on a Samba share?  
> their any Samba settings that could make this possible? It would be a  coup 
> Samba! 
> BTW, Apple's IMovie doesn't  go through this pre allocation  business. But, 
> alas, IMovie  doesn't capture timecode data, so Final Cut users  who want 
to work  
> with Samba shares can't simply switch to IMovie for capturing   their 

That's a Mac client issue. We do support "sparse"  pre-allocation on the
server side. I'd raise it as a bug with  Apple.


Isn't the Mac Samba Client compiled from a stock Samba samba.org source  
code? And if so, shouldn't it behave as any other Samba client. Or is Apple  doing 
their own thing with the Samba client? 
I've been Googling for information to see if it's possible to compile my  own 
Samba for OS X and haven't come up with much. 
If it IS an Apple bug, I would bet "dollars to doughnuts" that Apple will  
quietly neglect the issue. In my experience with the company, they don't want to 
 do ANYTHING that will help non-Apple products compete with Apple storage  
devices. They will simply leave it broken. 
That's not to say that it's the Samba Team's job to fix it. I've just been  
dealing with Apple Final Cut Pro developers for a long time and I know of  what 
I speak! All I've gotten out of them is "it's the Quicktime API that's  
responsible, and they'll have to change Quicktime to change the behavior when  
writing to a Samba share."
Does that ring true to you? 
Have you heard of XSan and XServe RAID? 
Andy Liebman

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