From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:39921) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1dGBhp-0002Pi-Or for guix-patches@gnu.org; Wed, 31 May 2017 18:03:06 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1dGBhm-0005yM-LJ for guix-patches@gnu.org; Wed, 31 May 2017 18:03:05 -0400 Received: from debbugs.gnu.org ([208.118.235.43]:45395) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1dGBhm-0005yF-Im for guix-patches@gnu.org; Wed, 31 May 2017 18:03:02 -0400 Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1dGBhm-0005XZ-4p for guix-patches@gnu.org; Wed, 31 May 2017 18:03:02 -0400 Subject: bug#27162: [PATCH 0/6] Display how much will be downloaded Resent-Message-ID: MIME-Version: 1.0 In-Reply-To: <20170531233931.2f6540c6@scratchpost.org> References: <20170531134941.8012-1-ludo@gnu.org> <20170531233931.2f6540c6@scratchpost.org> From: Maxim Cournoyer Date: Wed, 31 May 2017 15:02:08 -0700 Message-ID: Content-Type: multipart/alternative; boundary="089e0822dda04c479e0550d9123b" List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guix-patches-bounces+kyle=kyleam.com@gnu.org Sender: "Guix-patches" To: Danny Milosavljevic Cc: 27162@debbugs.gnu.org --089e0822dda04c479e0550d9123b Content-Type: text/plain; charset="UTF-8" Hi, On Wed, May 31, 2017 at 2:39 PM, Danny Milosavljevic wrote: > Hi, > > On Wed, 31 May 2017 12:42:29 -0700 > Maxim Cournoyer wrote: > > > This is really neat! Thanks for that. Shouldn't the default behavior > > of build to stop right there (even without the -n flag) and errors out > > when it "knows" there won't be enough space to successfully build the > > derivations? > > It doesn't know it. > > Modern filesystems can compress on-the-fly. What free-disk-space shows is > just a guess and it really depends on the exact content you write whether > it will fit or not. > > Also, filesystems with deduplication will store content just once > (basically at the sector with the number equal to the hash of the content) > and just reuse the same sectors for other files. That, too would be > misjudged. > > Then there are quotas, if there's a quota for a specific user only this > user's files will be limited (much earlier). Not supported either. > > Then there can be storage reserved for the root user - and if you are > non-root, you won't get it, even if it's technically "available". > > Then there's clustering overhead. Depending on the size of the individual > files it can take (sometimes) much more space to actually store those files > than you think. > > Therefore I think a warning is better. It can easily have both false > positives and false negatives. > > I like the feature, though. Also the download size feature. Nice :D > Right. Making it an error would also open the door for bug reports. So yes, I think you are right, this should be a warning rather than an error. Thanks! Maxim --089e0822dda04c479e0550d9123b Content-Type: text/html; charset="UTF-8" Content-Transfer-Encoding: quoted-printable
Hi,

On Wed, May 31, 2017 at 2:39 PM, Danny Milosavljevic <da= nnym@scratchpost.org> wrote:

On Wed, 31 May 2017 12:42:29 -0700
Maxim Cournoyer <maxim.cour= noyer@gmail.com> wrote:

> This is really neat! Thanks for that. Shouldn't the default behavi= or
> of build to stop right there (even without the -n flag) and errors out=
> when it "knows" there won't be enough space to successfu= lly build the
> derivations?

It doesn't know it.

Modern filesystems can compress on-the-fly.=C2=A0 What free-disk-space show= s is just a guess and it really depends on the exact content you write whet= her it will fit or not.

Also, filesystems with deduplication will store content just once (basicall= y at the sector with the number equal to the hash of the content) and just = reuse the same sectors for other files.=C2=A0 That, too would be misjudged.=

Then there are quotas, if there's a quota for a specific user only this= user's files will be limited (much earlier).=C2=A0 Not supported eithe= r.

Then there can be storage reserved for the root user - and if you are non-r= oot, you won't get it, even if it's technically "available&quo= t;.

Then there's clustering overhead.=C2=A0 Depending on the size of the in= dividual files it can take (sometimes) much more space to actually store th= ose files than you think.

Therefore I think a warning is better.=C2=A0 It can easily have both false = positives and false negatives.

I like the feature, though.=C2=A0 Also the download size feature.=C2=A0 Nic= e :D

Right. Making it an= error would also open the door for bug reports. So yes, I think you are ri= ght, this should be a warning rather than an error.

Thanks!

Maxim
<= /div>
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