[Info-vax] Anyone interested in another public access system

[Tom Linden]

On Mon, 13 Apr 2009 14:22:11 -0700, FredK <fred.nospam at dec.com> wrote:

>
> "Richard B. Gilbert" <rgilbert88 at comcast.net> wrote in message
> news:8_SdnVfP4607PX7UnZ2dnUVZ_iydnZ2d at giganews.com...
>> FredK wrote:
>>> "Richard B. Gilbert" <rgilbert88 at comcast.net> wrote in message
>>> news:BtydneYdGuPi-37UnZ2dnUVZ_oydnZ2d at giganews.com...
>>>
>>>> Isn't there an ODS-5 now?  ISTR reading about the new file system that
>>>> allows all kinds of special characters in filenames.
>>>>
>>>> I've been using ODS-2 for a bit more than 23 years now.  It does just
>>>> about everything I need in a file system.  Needless to say, I do NOT
>>>> need files named #@!$$xqb.|\23^@# or any other such frippery!
>>>>
>>>> I know, I know, I'm hopelessly old fashioned.
>>>
>>> ODS-5 is ODS-2 with extended name support.  Recently we've even tacked  
>>> on
>>> UNIX hard and soft links.
>>>
>>> But the basic problem is that the file system is a living antique of
>>> design and is very slow compared to a modern file system.
>>>
>>
>> I never noticed this slowness.  Perhaps I just wasn't paying attention.
>>
>> What would you cite as an example of a "modern" file system?  Most Unix
>> systems won't even commit your file to disk until they get around to it.
>> One of the nice things about VMS is that what you write to disk is
>> actually committed to disk within a few seconds.  A power failure does  
>> not
>> always require repairs to a VMS file system; something that can't be  
>> said
>> for Unix.  Unix provides no means to create a contiguous file; just
>> splatter it all over the disk!.  Even <obligatory retching noises>  
>> Windows
>> has a utility to make your files and free space contiguous. Unix just
>> doesn't care.
>>
>> Except for Sun's ZFS, I think most Unix file systems have changed very
>> little in the last ten or twenty years.
>>
>
> Except for some extensions, ODS hasn't changed much since the PDP11 and
> RSX11M.  ODS suffers in terms of very large files, and very large  
> numbers of
> files.  Take a look at a file system like XFS (SGI circa mid-to-late
> 1990's).
>
> As to the pro's and con's of file system caching, would it not be better  
> if
> the user (or programmer) could determine how critical the data is?  On a
> UNIX system, a temporary file might be created and deleted without any of
> the bits ever hitting a physical disk.  If that file was transient data -
> why would you care that it was cached?  Or if the file structure was ever
> updated?

Checkpoint restart.  Of course putting that into Unix might be a challenge.

>
> http://www.oss.sgi.com/projects/xfs/papers/xfs_usenix/index.html
>
>



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