Re: freshly installed SW not found

From	William Unruh <unruh@invalid.ca>
Newsgroups	alt.os.linux
Subject	Re: freshly installed SW not found
Date	2019-02-27 23:02 +0000
Organization	A noiseless patient Spider
Message-ID	<q574v2$8h7$1@dont-email.me> (permalink)
References	(5 earlier) <q560n2$7vs$1@dont-email.me> <q56c4p$25f$2@dont-email.me> <slrnq7dd48.3t0.dan@djph.net> <q56pf6$1l5$1@dont-email.me> <q56rgs$eab$1@dont-email.me>

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On 2019-02-27, Aragorn <thorongil@telenet.be> wrote:
> On Wed, 27 Feb 2019 20:46:45 +0100, Soviet_Mario scribbled:
>
>> On 27/02/19 17:02, Dan Purgert wrote:
>>> -----BEGIN PGP SIGNED MESSAGE-----
>>> Hash: SHA256
>>> 
>>> Soviet_Mario wrote:
>>>> On 27/02/19 13:44, Aragorn wrote:
>>>>> On Wed, 27 Feb 2019 12:52:04 +0100, Soviet_Mario scribbled:
>>>>>
>>>>>> On 26/02/19 22:46, William Unruh wrote:
>>>>>>
>>>>>>> Something like rsnapshot (using rsync) will store about 30 backups
>>>>>>> of 200GB of data in half a TB. (it does differential backups so
>>>>>>> only files which changed get backed up).
>>>>>>>
>>>>>>> Not tarring or compressing means that the backup data is easy to
>>>>>>> get at which is usually what you want.
>>>>>>
>>>>>> I call this inode space pollution, a thing that I don't find
>>>>>> desirable on the backup target (even if I have to accept it in the
>>>>>> userspace). It slows down searches, takes up space in itself just to
>>>>>> store a huge number of inodes :\
>>>>>
>>>>> rsnapshot uses hard-linking for files that haven't changed since the
>>>>> last backup.  Hard links don't use up any inodes.
>>>>>
>>>>>
>>>> mmm, then I must have chosen the wrong terms.
>>>> But some other kind of disk space must be used to add a link
>>> 
>>> Nope.
>> 
>> so the link information is stored where ?
>
> In the inode itself.
>
>> I'm not saying the content need to be stored, but the link to it for
>> sure : in as many places as there are the links
>> 
>> This does not duplicate the info of Inode (Aragorns taught),
>> but then the link is a reference to be dereferenced.
>
> No more or no less than the original link.
>
>> So when the file manager scans the disk, re-read the same inode many
>> times or at best looks-up some hash table to find whether or not the
>> info is just present.
>
> Nothing of that sort.  The link is stored in the inode's link counter 
> itself.  When the link is zero, the file's extents are released for reuse 
> by other files, i.e. the file is considered deleted.  A single file can 
> have a hundred hard links, and it still wouldn't take any more time to 
> read than if it had only one link.

Of course if you sequentially read the hundred files which all point to
the same inode, it will take 100 times as long as reading from one of
those files. But that would also be true if you read the same file 100
times, because that is what you are doing. (I am neglecting buffering,
etc)
 

 It has never been entirely clear to me if the inode saves a reference
 to the files pointing to it. Ie, if you know the inode, can you
 determine all of the files that are hard linked to it, without haveing
 to scan the whole directory structure to fine those files that point to
 it. For example, rsync can preserve hard links. How does it know that
 file B is a hardlink to a file already read as file A, if it does?

>

Thread

freshly installed SW not found Soviet_Mario <SovietMario@CCCP.MIR> - 2019-02-26 19:47 +0100
  Re: freshly installed SW not found "J.O. Aho" <user@example.net> - 2019-02-26 20:28 +0100
    Re: freshly installed SW not found Soviet_Mario <SovietMario@CCCP.MIR> - 2019-02-26 21:51 +0100
      Re: freshly installed SW not found William Unruh <unruh@invalid.ca> - 2019-02-26 21:46 +0000
        Re: freshly installed SW not found Soviet_Mario <SovietMario@CCCP.MIR> - 2019-02-27 12:52 +0100
          Re: freshly installed SW not found Aragorn <thorongil@telenet.be> - 2019-02-27 12:44 +0000
            Re: freshly installed SW not found Dan Purgert <dan@djph.net> - 2019-02-27 13:27 +0000
            Re: freshly installed SW not found Richard Kettlewell <invalid@invalid.invalid> - 2019-02-27 15:16 +0000
            Re: freshly installed SW not found Soviet_Mario <SovietMario@CCCP.MIR> - 2019-02-27 16:59 +0100
              Re: freshly installed SW not found Dan Purgert <dan@djph.net> - 2019-02-27 16:02 +0000
                Re: freshly installed SW not found Soviet_Mario <SovietMario@CCCP.MIR> - 2019-02-27 20:46 +0100
                Re: freshly installed SW not found William Unruh <unruh@invalid.ca> - 2019-02-27 20:18 +0000
                Re: freshly installed SW not found Soviet_Mario <SovietMario@CCCP.MIR> - 2019-02-28 12:47 +0100
                Re: freshly installed SW not found William Unruh <unruh@invalid.ca> - 2019-02-28 18:32 +0000
                Re: freshly installed SW not found Soviet_Mario <SovietMario@CCCP.MIR> - 2019-03-01 01:14 +0100
                Re: freshly installed SW not found "Carlos E.R." <robin_listas@es.invalid> - 2019-03-01 01:54 +0100
                Re: freshly installed SW not found Jasen Betts <jasen@xnet.co.nz> - 2019-03-01 03:09 +0000
                Re: freshly installed SW not found Aragorn <thorongil@telenet.be> - 2019-02-27 20:21 +0000
                Re: freshly installed SW not found William Unruh <unruh@invalid.ca> - 2019-02-27 23:02 +0000
                Re: freshly installed SW not found Richard Kettlewell <invalid@invalid.invalid> - 2019-02-27 23:24 +0000
                Re: freshly installed SW not found Jasen Betts <jasen@xnet.co.nz> - 2019-02-28 04:46 +0000
                Re: freshly installed SW not found Dan Purgert <dan@djph.net> - 2019-02-28 10:59 +0000
                Re: freshly installed SW not found Soviet_Mario <SovietMario@CCCP.MIR> - 2019-02-28 18:51 +0100
                Re: freshly installed SW not found William Unruh <unruh@invalid.ca> - 2019-02-28 18:24 +0000
                Re: freshly installed SW not found Dan Purgert <dan@djph.net> - 2019-03-01 13:49 +0000
                Re: freshly installed SW not found "Carlos E.R." <robin_listas@es.invalid> - 2019-03-01 18:22 +0100
                Re: freshly installed SW not found Aragorn <thorongil@telenet.be> - 2019-03-01 19:06 +0000
                Re: freshly installed SW not found Soviet_Mario <SovietMario@CCCP.MIR> - 2019-03-03 01:08 +0100
                Re: freshly installed SW not found Aragorn <thorongil@telenet.be> - 2019-03-03 00:14 +0000
                Re: freshly installed SW not found Dan Purgert <dan@djph.net> - 2019-03-03 13:00 +0000
                Re: freshly installed SW not found Dan Purgert <dan@djph.net> - 2019-03-03 12:46 +0000
                Re: freshly installed SW not found William Unruh <unruh@invalid.ca> - 2019-02-28 18:15 +0000
              Re: freshly installed SW not found William Unruh <unruh@invalid.ca> - 2019-02-27 16:38 +0000
                Re: freshly installed SW not found Soviet_Mario <SovietMario@CCCP.MIR> - 2019-02-27 20:51 +0100
              Re: freshly installed SW not found Jasen Betts <jasen@xnet.co.nz> - 2019-02-28 04:39 +0000
        Re: freshly installed SW not found "Carlos E.R." <robin_listas@es.invalid> - 2019-02-27 14:30 +0100
      Re: freshly installed SW not found "J.O. Aho" <user@example.net> - 2019-02-27 07:05 +0100
      Re: freshly installed SW not found "Carlos E.R." <robin_listas@es.invalid> - 2019-02-27 14:29 +0100
        Re: freshly installed SW not found Paul <nospam@needed.invalid> - 2019-02-27 08:50 -0500
          Re: freshly installed SW not found "Carlos E.R." <robin_listas@es.invalid> - 2019-02-28 00:05 +0100
        Re: freshly installed SW not found Soviet_Mario <SovietMario@CCCP.MIR> - 2019-02-27 16:56 +0100
        Re: freshly installed SW not found Chris <ithinkiam@gmail.com> - 2019-03-01 14:58 +0000
      Re: freshly installed SW not found Chris <ithinkiam@gmail.com> - 2019-03-01 15:04 +0000
        Re: freshly installed SW not found "David W. Hodgins" <dwhodgins@nomail.afraid.org> - 2019-03-01 10:50 -0500
          Re: freshly installed SW not found William Unruh <unruh@invalid.ca> - 2019-03-01 18:40 +0000
            Re: freshly installed SW not found "David W. Hodgins" <dwhodgins@nomail.afraid.org> - 2019-03-01 14:40 -0500
              Re: freshly installed SW not found William Unruh <unruh@invalid.ca> - 2019-03-01 23:38 +0000
                Re: freshly installed SW not found "David W. Hodgins" <dwhodgins@nomail.afraid.org> - 2019-03-01 19:09 -0500
                Re: freshly installed SW not found William Unruh <unruh@invalid.ca> - 2019-03-02 03:47 +0000
                Re: freshly installed SW not found "David W. Hodgins" <dwhodgins@nomail.afraid.org> - 2019-03-01 22:55 -0500
                Re: freshly installed SW not found William Unruh <unruh@invalid.ca> - 2019-03-02 07:08 +0000
                Re: freshly installed SW not found "Carlos E.R." <robin_listas@es.invalid> - 2019-03-02 11:27 +0100
                Re: freshly installed SW not found Paul <nospam@needed.invalid> - 2019-03-02 04:10 -0500
                Re: freshly installed SW not found William Unruh <unruh@invalid.ca> - 2019-03-02 16:29 +0000
                Re: freshly installed SW not found Paul <nospam@needed.invalid> - 2019-03-02 11:54 -0500
                Re: freshly installed SW not found "Carlos E.R." <robin_listas@es.invalid> - 2019-03-02 11:24 +0100
                Re: freshly installed SW not found Jasen Betts <jasen@xnet.co.nz> - 2019-03-02 00:28 +0000
                Re: freshly installed SW not found "Carlos E.R." <robin_listas@es.invalid> - 2019-03-02 11:31 +0100
                Re: freshly installed SW not found Aragorn <thorongil@telenet.be> - 2019-03-02 11:31 +0000
                Re: freshly installed SW not found Melzzzzz <Melzzzzz@zzzzz.com> - 2019-03-02 11:34 +0000
                Re: freshly installed SW not found Aragorn <thorongil@telenet.be> - 2019-03-02 11:48 +0000
                Re: freshly installed SW not found Melzzzzz <Melzzzzz@zzzzz.com> - 2019-03-02 12:15 +0000
                Re: freshly installed SW not found "Carlos E.R." <robin_listas@es.invalid> - 2019-03-02 23:15 +0100
                Re: freshly installed SW not found Chris Elvidge <chris@mshome.net> - 2019-03-03 00:33 +0000
                Re: freshly installed SW not found Soviet_Mario <SovietMario@CCCP.MIR> - 2019-03-03 01:38 +0100
                Compressed filesystems [Was: Re: freshly installed SW not found] "Carlos E.R." <robin_listas@es.invalid> - 2019-03-03 13:11 +0100
                Re: Compressed filesystems [Was: Re: freshly installed SW not found] Soviet_Mario <SovietMario@CCCP.MIR> - 2019-03-03 19:49 +0100
                Re: Compressed filesystems [Was: Re: freshly installed SW not found] "Carlos E.R." <robin_listas@es.invalid> - 2019-03-03 21:17 +0100
                Re: freshly installed SW not found Dan Purgert <dan@djph.net> - 2019-03-03 12:49 +0000
                Re: freshly installed SW not found Melzzzzz <Melzzzzz@zzzzz.com> - 2019-03-03 12:35 +0000
            Re: freshly installed SW not found "Carlos E.R." <robin_listas@es.invalid> - 2019-03-02 11:22 +0100
  Re: freshly installed SW not found Wildman <best_lay@yahoo.com> - 2019-02-26 13:31 -0600
    Re: freshly installed SW not found Wildman <best_lay@yahoo.com> - 2019-02-26 15:42 -0600
      Re: freshly installed SW not found William Unruh <unruh@invalid.ca> - 2019-02-26 21:51 +0000
  Re: freshly installed SW not found "David W. Hodgins" <dwhodgins@nomail.afraid.org> - 2019-02-26 14:36 -0500
    Re: freshly installed SW not found Soviet_Mario <SovietMario@CCCP.MIR> - 2019-02-26 21:58 +0100
      Re: freshly installed SW not found William Unruh <unruh@invalid.ca> - 2019-02-26 21:49 +0000
        Re: freshly installed SW not found Soviet_Mario <SovietMario@CCCP.MIR> - 2019-02-27 12:54 +0100
  Re: freshly installed SW not found William Unruh <unruh@invalid.ca> - 2019-02-26 19:51 +0000

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