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Re: Multithreaded disk access

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On 10/18/2021 2:46 PM, Dimiter_Popoff wrote:
>> By contrast, the other disks in the machine all see a fair bit of
>> turnover as things get created, revised and deleted.
> 
> Now this is where the worst fit allocation strategy becomes the game
> changer. A newly created file is almost certainly contiguously
> allocated; fragmentation occurs when it is appended to (and the
> space past its last block has been already allocated in the meantime).
> I think I saw somewhere (never really got interested) that mainstream
> operating systems of today do just first fit

Dunno.  There are *lots* of different "file systems".  And, as most
systems use the filesystem for its global namespace, the term is
sadly overloaded (in ways that have nothing to do with storage media).

I don't use large secondary stores in my designs.  Where "big storage"
is required, it is accessed remotely (network) so the problem of
dealing with it is not mine.  E.g., in my current project, there is
no file system exposed; any persistent storage is done via "tables"
that are created, as needed (by the system and its apps) in a remote
database server.

[This lets me delegate the issue of data retention to a specific box.
And, also lets me impart structure to the data that is stored.  So,
for example, I can find the most recent firmware image for a particular
hardware module by just issuing a query and waiting on the result
instead of having to parse a bunch of names, somewhere in a
filesystem/namespace, looking for the one that has the highest
rev level IN its name:  firmware_1.0.1, firmware_1.0.2, firmware_5.3,
firmware 6.1 (typo!  the '_' was omitted -- will the parse algorithm
choke on that omission??)]

> - which means once you
> delete a file, no matter how small, its space will be allocated as
> part of the next request etc., no idea why they do it (if they do so,
> my memory on that is not very certain) in such a primitive manner
> but here they are.

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Multithreaded disk access Don Y <blockedofcourse@foo.invalid> - 2021-10-15 07:08 -0700
  Re: Multithreaded disk access Richard Damon <Richard@Damon-Family.org> - 2021-10-15 11:38 -0400
    Re: Multithreaded disk access Don Y <blockedofcourse@foo.invalid> - 2021-10-15 09:00 -0700
      Re: Multithreaded disk access Richard Damon <Richard@Damon-Family.org> - 2021-10-15 12:48 -0400
        Re: Multithreaded disk access Don Y <blockedofcourse@foo.invalid> - 2021-10-15 11:40 -0700
  Re: Multithreaded disk access Dimiter_Popoff <dp@tgi-sci.com> - 2021-10-15 18:46 +0300
    Re: Multithreaded disk access Don Y <blockedofcourse@foo.invalid> - 2021-10-15 09:19 -0700
      Re: Multithreaded disk access Dimiter_Popoff <dp@tgi-sci.com> - 2021-10-15 19:28 +0300
  Re: Multithreaded disk access Brett <ggtgp@yahoo.com> - 2021-10-17 20:27 +0000
    Re: Multithreaded disk access Don Y <blockedofcourse@foo.invalid> - 2021-10-17 14:49 -0700
      Re: Multithreaded disk access Don Y <blockedofcourse@foo.invalid> - 2021-10-17 15:01 -0700
      Re: Multithreaded disk access Dimiter_Popoff <dp@tgi-sci.com> - 2021-10-18 01:09 +0300
        Re: Multithreaded disk access Don Y <blockedofcourse@foo.invalid> - 2021-10-18 08:05 -0700
          Re: Multithreaded disk access Dimiter_Popoff <dp@tgi-sci.com> - 2021-10-18 19:25 +0300
            Re: Multithreaded disk access Don Y <blockedofcourse@foo.invalid> - 2021-10-18 13:46 -0700
              Re: Multithreaded disk access Dimiter_Popoff <dp@tgi-sci.com> - 2021-10-19 00:46 +0300
                Re: Multithreaded disk access Don Y <blockedofcourse@foo.invalid> - 2021-10-18 16:17 -0700
                Re: Multithreaded disk access antispam@math.uni.wroc.pl - 2021-10-31 19:21 +0000
                Re: Multithreaded disk access Dimiter_Popoff <dp@tgi-sci.com> - 2021-10-31 21:55 +0200
              Re: Multithreaded disk access Don Y <blockedofcourse@foo.invalid> - 2021-10-25 04:19 -0700
                Re: Multithreaded disk access Richard Damon <Richard@Damon-Family.org> - 2021-10-25 20:23 -0400
                Re: Multithreaded disk access Don Y <blockedofcourse@foo.invalid> - 2021-10-25 22:29 -0700
      Re: Multithreaded disk access Clifford Heath <no.spam@please.net> - 2021-10-18 11:58 +1100

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