From mboxrd@z Thu Jan 1 00:00:00 1970 From: ludo@gnu.org (Ludovic =?utf-8?Q?Court=C3=A8s?=) Subject: Re: Guix on aarch64 Date: Fri, 24 Aug 2018 12:32:38 +0200 Message-ID: <87zhxcoy0p.fsf@gnu.org> References: <87mutm72n7.fsf@jnanam.net> <878t565k85.fsf@lassieur.org> <87k1oq6wgf.fsf@jnanam.net> <87bm9tbrx9.fsf@netris.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Return-path: Received: from eggs.gnu.org ([2001:4830:134:3::10]:52857) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ft9OV-0005VI-RY for guix-devel@gnu.org; Fri, 24 Aug 2018 06:32:44 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ft9OS-00060s-KG for guix-devel@gnu.org; Fri, 24 Aug 2018 06:32:43 -0400 In-Reply-To: <87bm9tbrx9.fsf@netris.org> (Mark H. Weaver's message of "Thu, 23 Aug 2018 00:58:10 -0400") List-Id: "Development of GNU Guix and the GNU System distribution." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: guix-devel-bounces+gcggd-guix-devel=m.gmane.org@gnu.org Sender: "Guix-devel" To: Mark H Weaver Cc: guix-devel@gnu.org, Benjamin Slade Hello Mark, Mark H Weaver skribis: > If I'm not mistaken, I believe I have confirmed with the test below that > a substitute for binutils from early commencement on aarch64 is not > available on berlin. [...] > It occurs to me that on Hydra, I have implemented a system to ensure > that *all* derivations from a certain set of _evaluations_ (the most > recent release and the last two weeks of 'master' evaluations) are > permanently kept as GC roots, regardless of how long ago they were > built. Among other things, this ensures that even the early > commencement derivations are kept even if they were built a long time > ago. > > Berlin.guixsd.org may not have any similar mechanism in place. It may > still be using the old policy, where old GC roots are deleted based > solely on their timestamps in the filesystem, which indicate when the GC > root symlinks were first installed, long ago during the last core > updates build-out. This could result in the early commencement > derivations and corresponding outputs being deleted prematurely. Correct. Berlin uses =E2=80=98guix publish=E2=80=99 with a TTL of 45 days:= if a nar is not requested within 45 days, and if its corresponding store item was GC=E2=80=99d in the meantime, it disappears. I think there are two problems that made that happen: our two aarch64 build machines have been offline for several weeks so nothing new gets built, and aarch64 substitutes are probably unpopular and thus more likely to disappear given the above policy. We=E2=80=99ll probably need a mechanism similar to what Hydra and you are d= oing on hydra.gnu.org, to explicitly retain derivations from certain evaluations; we can implement that in Cuirass. In addition, Ricardo has a plan to throw more storage at berlin (we currently have 1TB for the store). That would allow us to increase the TTL and generally worry less, though it=E2=80=99s no substitute for the GC = root mechanism above. (That said, the error Benjamin reported appears to be a build failure, which is surely worth investigating in its own right.) Thanks, Ludo=E2=80=99.