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Groups > comp.os.linux.advocacy > #289469

Re: ext4 vs btrfs - a new winner!

From Peter Köhlmann <peter-koehlmann@t-online.de>
Newsgroups comp.os.linux.advocacy
Subject Re: ext4 vs btrfs - a new winner!
Date 2015-04-13 21:43 +0200
Organization SMP
Message-ID <mgh67d$v9e$1@dont-email.me> (permalink)
References (3 earlier) <D151296C.4A0CE%usenet@gallopinginsanity.com> <mggs5o$ipb$1@dont-email.me> <D1515160.4A10D%usenet@gallopinginsanity.com> <mgh2r9$h17$1@dont-email.me> <D15161E4.4A135%usenet@gallopinginsanity.com>

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Snit wrote:

> On 4/13/15, 11:45 AM, in article mgh2r9$h17$1@dont-email.me, "Peter
> Köhlmann" <peter-koehlmann@t-online.de> wrote:
> 
>> Snit wrote:
>> 
>>> On 4/13/15, 9:52 AM, in article mggs5o$ipb$1@dont-email.me, "Slimer"
>>> <slvrslmr@lv.c> wrote:
>>> 
>>>>>> Apple most likely won't ever use it. They might inspire themselves
>>>>>> off of it to make their own filesystem but I just don't see them
>>>>>> using an open-source filesystem, especially since these tend to
>>>>>> continuously evolve and potentially break things along the way.
>>>>>> 
>>>>> Well, they would need something that works with Time Machine... unless
>>>>> they kept Time Machine on its current file system for now. As it is
>>>>> they have HFS+ set up a bit differently for it than for the main drive
>>>>> (I think).
>>>> 
>>>> I'm not sure why they wouldn't be able to adapt their Time Machine
>>>> hardware and software to be used on an open-source filesystem. Nothing
>>>> is set in stone the way I see it.
>>> 
>>> They could - but right now Time Machine uses hard linked directories.
>>> This is something that is generally *not* allowed on Linux / UNIX
>>> systems but it makes it so Time Machine can be much more efficient. A
>>> good write up of it is here:
>>> 
>>> <http://arstechnica.com/apple/2007/10/mac-os-x-10-5/14/>
>>>     -----
>>>     Time Machine goes one step further. Historically, Unix has only
>>>     allowed hard links to files. In Leopard, Apple has included the
>>>     ability to make hard links to directories. This has not been
>>>     allowed in Unix because it can lead to all sorts of very nasty
>>>     infinite loops during file look-ups. Of course, symbolic links can
>>>     create loops too, but they're a lot easier to detect and prevent
>>>     since symbolic links are easily distinguished from normal files.
>>>     But as discussed earlier, every file is essentially a hard link,
>>>     and all hard links have equal standing in the eyes of the OS,
>>>     making loop detection a bit trickier.
>>> 
>>>     Nevertheless, the benefits for Time Machine were substantial
>>>     enough for Apple to (carefully) add this ability to Leopard. For
>>>     example, if the entire /System directory has not changed since the
>>>     last backup, Time Machine just has to make a single hard link to
>>>     that directory in the new backup folder. Without support for hard
>>>     links to directories, Time Machine would have to create 18,744
>>>     directories containing a total of 68,839 hard links to files
>>>     (using numbers from my /System directory).
>>> 
>>>     Yes, directories are small and hard links only take up the room
>>>     necessary for their directory entries (at minimum, enough to store
>>>     the name and a pointer to the data on disk), but those bytes add
>>>     up fast when you're talking tens of thousands of hard links being
>>>     created every time you want to do a backup. Hard links to
>>>     directories make this all much simpler and more efficient.
>> 
>> 
>> So you actually learned something from my claim that hardlinks are
>> dangerous
> 
> That is from Ars Technica. Not you. And I read that well before we talked
> here... and already knew of hard links before then.
> 
>>> This capability, as far as I know, does not exist on Linux.
>> 
>> Sure it does. It is just not allowed, the tools to create links will not
>> create them for directories.
> 
> So it exists but is not allowed. Um, that is not really existing.
> 
>> *If* you knew at'least the most trivial things about unix in general, you
>> would know that a directory in unix is also just a file.
> 
> Nobody said otherwise. Nobody hinted otherwise.
> 
>> It just gets a flag combination that denotes it as a directory instead of
>> a normal file. otherwise it is a bog standard file. And hard links are
>> made to files. Remove the test for directories in the ln-program, and it
>> will make hardlinks to directories. With all of the possible nasties,
>> which not just include infinite loops, but also complete data loss
>> (remove a hard linked directory, and you will possibly lose *all* its
>> content)
> 
> Remove the *last* hard link.
>

You are truly the idiot you were always showing here.
If you make a hard link to a directory, there is just a single copy of it 
with several entries in the iNode tables.
All content in it exists only *once* and if you remove a file in a 
hardlinked directory, it is *gone* and the second / third /x hardlink to 
that directory will not change anything about it, because they all point to 
the exact same directory.

Gods, are you dense. You actually "teach" computing? All your "customers" 
should demand their money back with interest, because you are the most 
incompetent idiot in "teaching computers" out there. A demented cow would do 
that job better than you could ever hope

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Thread

ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-12 21:03 -0400
  Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-12 19:34 -0700
    Re: ext4 vs btrfs - a new winner! Melzzzzz <mel@zzzzz.com> - 2015-04-13 05:21 +0200
      Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-12 21:51 -0700
        Re: ext4 vs btrfs - a new winner! taka0038@gmail.com - 2015-04-13 01:16 -0700
          Re: ext4 vs btrfs - a new winner! John Gohde <john.h.gohde@gmail.com> - 2015-04-13 02:17 -0700
            Re: ext4 vs btrfs - a new winner! Desk Rabbit <me@example.com> - 2015-04-13 14:13 +0100
              Re: ext4 vs btrfs - a new winner! John Gohde <john.h.gohde@gmail.com> - 2015-04-13 06:16 -0700
                Re: ext4 vs btrfs - a new winner! Desk Rabbit <me@example.com> - 2015-04-13 15:30 +0100
              Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-13 10:49 -0400
                Re: ext4 vs btrfs - a new winner! Desk Rabbit <me@example.com> - 2015-04-13 16:37 +0100
                Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-13 12:58 -0400
              Re: ext4 vs btrfs - a new winner! GreyCloud <mist@cumulus.com> - 2015-04-13 11:59 -0600
                Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-13 17:37 -0400
          Re: ext4 vs btrfs - a new winner! Melzzzzz <mel@zzzzz.com> - 2015-04-13 11:54 +0200
            Re: ext4 vs btrfs - a new winner! GreyCloud <mist@cumulus.com> - 2015-04-13 11:58 -0600
              Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-13 17:37 -0400
                Re: ext4 vs btrfs - a new winner! DFS <nospam@dfs.com> - 2015-04-13 18:31 -0400
                Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-13 19:18 -0400
                Re: ext4 vs btrfs - a new winner! Peter Köhlmann <peter-koehlmann@t-online.de> - 2015-04-14 00:32 +0200
                Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-13 19:24 -0400
                Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-13 16:54 -0700
                Re: ext4 vs btrfs - a new winner! Desk Rabbit <me@example.com> - 2015-04-14 09:00 +0100
                Re: ext4 vs btrfs - a new winner! Peter Köhlmann <peter-koehlmann@t-online.de> - 2015-04-14 14:26 +0200
                Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-14 09:09 -0400
                Re: ext4 vs btrfs - a new winner! DFS <nospam@dfs.com> - 2015-04-14 09:11 -0400
                Re: ext4 vs btrfs - a new winner! Charlie Croyden <charlescroyden3@gmail.com> - 2015-04-14 06:14 -0700
                Re: ext4 vs btrfs - a new winner! DFS <nospam@dfs.com> - 2015-04-14 09:23 -0400
                Re: ext4 vs btrfs - a new winner! Peter Köhlmann <peter-koehlmann@t-online.de> - 2015-04-14 15:58 +0200
                Re: ext4 vs btrfs - a new winner! DFS <nospam@dfs.com> - 2015-04-14 10:14 -0400
                Re: ext4 vs btrfs - a new winner! Peter Köhlmann <peter-koehlmann@t-online.de> - 2015-04-14 16:22 +0200
                Re: ext4 vs btrfs - a new winner! DFS <nospam@dfs.com> - 2015-04-14 10:52 -0400
                Re: ext4 vs btrfs - a new winner! Peter Köhlmann <peter-koehlmann@t-online.de> - 2015-04-14 17:25 +0200
                Re: ext4 vs btrfs - a new winner! DFS <nospam@dfs.com> - 2015-04-14 12:01 -0400
                Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-14 12:23 -0400
                Re: ext4 vs btrfs - a new winner! DFS <nospam@dfs.com> - 2015-04-14 12:40 -0400
                Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-14 13:25 -0400
                Re: ext4 vs btrfs - a new winner! cc <scatnubbs@hotmail.com> - 2015-04-14 10:30 -0700
                Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-14 10:57 -0700
                Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-14 11:44 -0700
                Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-14 11:55 -0700
                Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-14 11:56 -0700
                Re: ext4 vs btrfs - a new winner! DFS <nospam@dfs.com> - 2015-04-14 18:14 -0400
                Re: ext4 vs btrfs - a new winner! tmelmosfire <tmelmosfire@gmail.com> - 2015-04-14 15:25 -0700
                Re: ext4 vs btrfs - a new winner! Steve Carroll <fretwizzer@gmail.com> - 2015-04-14 16:02 -0700
                Re: ext4 vs btrfs - a new winner! DFS <nospam@dfs.com> - 2015-04-14 19:21 -0400
                Re: ext4 vs btrfs - a new winner! Steve Carroll <fretwizzer@gmail.com> - 2015-04-14 16:38 -0700
                Re: ext4 vs btrfs - a new winner! tmelmosfire <tmelmosfire@gmail.com> - 2015-04-14 17:49 -0700
                Re: ext4 vs btrfs - a new winner! DFS <nospam@dfs.com> - 2015-04-14 19:15 -0400
                Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-14 18:36 -0400
                Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-14 15:39 -0700
                Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-14 20:19 -0400
                Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-14 09:55 -0700
                Re: ext4 vs btrfs - a new winner! DFS <nospam@dfs.com> - 2015-04-14 12:59 -0400
                Re: ext4 vs btrfs - a new winner! chrisv <chrisv@nospam.invalid> - 2015-04-14 12:14 -0500
                Re: ext4 vs btrfs - a new winner! DFS <nospam@dfs.com> - 2015-04-14 17:41 -0400
                Re: ext4 vs btrfs - a new winner! ronb <ronb02NOSPAM@gmail.com> - 2015-04-15 00:50 +0000
                Re: ext4 vs btrfs - a new winner! GreyCloud <mist@cumulus.com> - 2015-04-14 20:29 -0600
                Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-14 19:44 -0700
                Re: ext4 vs btrfs - a new winner! DFS <nospam@dfs.com> - 2015-04-15 08:35 -0400
                Re: ext4 vs btrfs - a new winner! ronb <ronb02NOSPAM@gmail.com> - 2015-04-14 22:40 +0000
                Re: ext4 vs btrfs - a new winner! DFS <nospam@dfs.com> - 2015-04-14 19:36 -0400
                Re: ext4 vs btrfs - a new winner! Chris Ahlstrom <OFeem1987@teleworm.us> - 2015-04-14 20:11 -0400
                Re: ext4 vs btrfs - a new winner! chrisv <chrisv@nospam.invalid> - 2015-04-15 07:15 -0500
                Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-14 08:45 -0700
                Re: ext4 vs btrfs - a new winner! DFS <nospam@dfs.com> - 2015-04-14 12:01 -0400
                Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-14 10:19 -0700
                Re: ext4 vs btrfs - a new winner! Steve Carroll <fretwizzer@gmail.com> - 2015-04-14 10:28 -0700
                Re: ext4 vs btrfs - a new winner! DFS <nospam@dfs.com> - 2015-04-14 18:13 -0400
                Re: ext4 vs btrfs - a new winner! tmelmosfire <tmelmosfire@gmail.com> - 2015-04-14 15:21 -0700
                Re: ext4 vs btrfs - a new winner! DFS <nospam@dfs.com> - 2015-04-14 19:14 -0400
                Re: ext4 vs btrfs - a new winner! Desk Rabbit <me@example.com> - 2015-04-14 15:27 +0100
                Does "Ezekiel" agree? chrisv <chrisv@nospam.invalid> - 2015-04-14 10:07 -0500
                Re: Does "Ezekiel" agree? DFS <nospam@dfs.com> - 2015-04-14 11:20 -0400
                Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-14 12:13 -0400
                Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-14 10:43 -0400
                Re: ext4 vs btrfs - a new winner! JEDIDIAH <jedi@nomad.mishnet> - 2015-04-14 10:02 -0500
                Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-14 12:15 -0400
                Re: ext4 vs btrfs - a new winner! ronb <ronb02NOSPAM@gmail.com> - 2015-04-15 00:55 +0000
                Re: ext4 vs btrfs - a new winner! vallor <vallor@cultnix.org> - 2015-04-15 14:14 -0700
                Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-15 17:19 -0400
                Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-14 09:04 -0400
                Re: ext4 vs btrfs - a new winner! ronb <ronb02NOSPAM@gmail.com> - 2015-04-13 23:35 +0000
                Re: ext4 vs btrfs - a new winner! DFS <nospam@dfs.com> - 2015-04-13 19:43 -0400
                Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-13 18:00 -0700
                Re: ext4 vs btrfs - a new winner! DFS <nospam@dfs.com> - 2015-04-13 23:16 -0400
                Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-13 18:00 -0700
          Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-13 08:59 -0400
          Re: ext4 vs btrfs - a new winner! Desk Rabbit <me@example.com> - 2015-04-13 14:11 +0100
            Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-13 10:48 -0400
              Re: ext4 vs btrfs - a new winner! Desk Rabbit <me@example.com> - 2015-04-13 16:41 +0100
                Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-13 12:59 -0400
                Re: ext4 vs btrfs - a new winner! Peter Köhlmann <peter-koehlmann@t-online.de> - 2015-04-13 19:25 +0200
                Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-13 17:14 -0400
                Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-13 14:18 -0700
                Re: ext4 vs btrfs - a new winner! owl <owl@rooftop.invalid> - 2015-04-13 21:55 +0000
                Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-13 16:48 -0700
                Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-13 17:26 -0400
                Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-13 10:50 -0700
                Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-13 17:31 -0400
                Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-13 14:46 -0700
                Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-13 18:16 -0400
                Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-13 16:53 -0700
                Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-14 08:51 -0400
      Re: ext4 vs btrfs - a new winner! GreyCloud <mist@cumulus.com> - 2015-04-13 11:56 -0600
        Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-13 11:02 -0700
        Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-13 17:32 -0400
          Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-13 14:45 -0700
            Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-13 18:11 -0400
              Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-13 16:50 -0700
          Re: ext4 vs btrfs - a new winner! GreyCloud <mist@cumulus.com> - 2015-04-13 20:15 -0600
    Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-13 08:51 -0400
      Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-13 08:06 -0700
        Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-13 12:52 -0400
          Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-13 10:56 -0700
            Re: ext4 vs btrfs - a new winner! Peter Köhlmann <peter-koehlmann@t-online.de> - 2015-04-13 20:45 +0200
              Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-13 12:07 -0700
                Re: ext4 vs btrfs - a new winner! Peter Köhlmann <peter-koehlmann@t-online.de> - 2015-04-13 21:43 +0200
                Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-13 12:58 -0700
                Re: ext4 vs btrfs - a new winner! Peter Köhlmann <peter-koehlmann@t-online.de> - 2015-04-13 22:08 +0200
                Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-13 13:34 -0700
                Re: ext4 vs btrfs - a new winner! Steve Carroll <fretwizzer@gmail.com> - 2015-04-13 13:31 -0700
            Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-13 17:35 -0400
              Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-13 14:43 -0700
                Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-13 18:11 -0400
                Re: ext4 vs btrfs - a new winner! DFS <nospam@dfs.com> - 2015-04-13 18:30 -0400
                Re: ext4 vs btrfs - a new winner! Peter Köhlmann <peter-koehlmann@t-online.de> - 2015-04-14 00:35 +0200
                Re: ext4 vs btrfs - a new winner! DFS <nospam@dfs.com> - 2015-04-13 18:39 -0400
                Re: ext4 vs btrfs - a new winner! Peter Köhlmann <peter-koehlmann@t-online.de> - 2015-04-14 00:49 +0200
                Re: ext4 vs btrfs - a new winner! DFS <nospam@dfs.com> - 2015-04-13 18:50 -0400
                Re: ext4 vs btrfs - a new winner! owl <owl@rooftop.invalid> - 2015-04-13 23:11 +0000
                Re: ext4 vs btrfs - a new winner! owl <owl@rooftop.invalid> - 2015-04-13 23:08 +0000
                Re: ext4 vs btrfs - a new winner! ronb <ronb02NOSPAM@gmail.com> - 2015-04-13 23:37 +0000
                Re: ext4 vs btrfs - a new winner! Snit <usenet@gallopinginsanity.com> - 2015-04-13 17:59 -0700
                Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-13 19:40 -0400
                Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-13 19:16 -0400
  Re: ext4 vs btrfs - a new winner! Desk Rabbit <me@example.com> - 2015-04-13 16:43 +0100
    Re: ext4 vs btrfs - a new winner! Slimer <slvrslmr@lv.c> - 2015-04-13 13:00 -0400

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