retitle 474947 "fix Dynamic MMaps error" severity 474947 important tag 474947 -unreproducible thanks
hi bug, hi people, hi d-release I did some study on bug 474947, that is grave/RC, and is posted against APT. Since I was told that the APT team is understaffed, I decided to take action myself. --- First of all, I tried to focus the problem. In this same bug there were reported two different issues, a "Dynamic MMap error" and a segmentation fault; moreover some people were using APT in Etch, and some other in Lenny. Let's summarize it shortly. First poster is Elliot Mitchel, in Apr 08; he is using APT 0.6.46 inside Etch. He claims that he cannot work around a "Dynamic MMap" error; he then sets severity to grave. It turns out that he is using the wrong option, he is using '-o APT::Cache-File=200000000' instead of '-o APT::Cache-Limit=200000000' . (And that confuses "Joe Nahmias" and me as well - the mistake is noted by JackYF quite later). So the first report is flawed. jasen reports a similar problem, but I don't see enough details to comment. Then Elliott Mitchell again also posts a report about a segmentation fault. Some months go by; in Sept. JackYF offers to help fixing the problem by changing the code. (Unfortunately we are already in deep freeze, and I am afraid deep changes to APT would not be accepted by the release team.) ---- I did some more research around, and tests, and this is what I found out. The default in APT (inside the code) for Cache-Limit in Lenny is 20MB , in Etch is 8MB . Note also that in the Lenny release notes http://svn.debian.org/viewsvn/ddp/manuals/branches/release-notes/lenny/en/upgrading.dbk it is suggested to set Cache-Limit to 12500000 in case of Dynamic MMap error. I tested APT 0.6.46 in Etch. I tried with 3 different sources.list, see attachment. The "fat" list is the union of all lists of all reporters (minus obsolete and duplicates). The two smaller files work perfectly well; the "fat" sources file does trigger the DynamicMMap problem, that I can though work around by using 'apt-get -o APT::Cache-Limit=100000000 update' The only way to trigger a segmentation fault was instead to set Cache-Limit to a ridiculously low value. So my conclusion is that the forthcoming release notes do address the problem some people may encounter in upgrading from Etch to Lenny. I propose the attached patch, though, since it is funny to suggest a value of 12500000 (bytes) when the internal value in Lenny is 20MB. I hope someone in the d-relase team can apply it. a.
Index: manuals/branches/release-notes/lenny/en/upgrading.dbk =================================================================== --- manuals/branches/release-notes/lenny/en/upgrading.dbk (revisione 5426) +++ manuals/branches/release-notes/lenny/en/upgrading.dbk (copia locale) @@ -957,10 +957,11 @@ to a value that should be sufficient for the upgrade: </para> <screen> -# echo 'APT::Cache-Limit 12500000;' >> /etc/apt/apt.conf +# echo 'APT::Cache-Limit 21000000;' >> /etc/apt/apt.conf </screen> <para> -This assumes that you do not yet have this variable set in that file. +This assumes that you do not yet have this variable set in that file; +otherwise you may manually edit the file to set the above variable. </para> <para> Sometimes it's necessary to enable the <literal>APT::Force-LoopBreak</literal>
deb http://debian.oregonstate.edu/debian/ stable main contrib non-free deb http://security.debian.org stable/updates main contrib non-free deb http://www.debian-multimedia.org stable main deb http://volatile.debian.org/debian-volatile stable/volatile main contrib non-free deb http://debian.oregonstate.edu/debian/ testing main contrib non-free deb-src http://debian.oregonstate.edu/debian/ stable main contrib non-free deb-src http://security.debian.org stable/updates main contrib non-free deb-src http://www.debian-multimedia.org stable main deb-src http://volatile.debian.org/debian-volatile stable/volatile main contrib non-free deb-src http://debian.oregonstate.edu/debian/ testing main contrib non-free #--------- deb http://ftp.egr.msu.edu/debian/ unstable main contrib deb-src http://ftp.egr.msu.edu/debian/ unstable main contrib deb http://ftp.us.debian.org/debian/ unstable main contrib non-free deb-src http://ftp.us.debian.org/debian/ unstable main contrib non-free deb http://ftp.us.debian.org/debian/ etch main contrib non-free deb http://ftp.us.debian.org/debian/ lenny main contrib non-free deb-src http://mentors.debian.net/debian unstable main contrib #------------ deb ftp://ftp.nz.debian.org/debian etch main non-free contrib deb-src http://ftp.nz.debian.org/debian stable main non-free contrib deb http://ftp.nz.debian.org/debian lenny main contrib non-free deb http://ftp.nz.debian.org/debian unstable main contrib deb http://www.debian-multimedia.org etch main deb ftp://ftp.au.debian.org/debian etch main non-free contrib deb-src http://ftp.au.debian.org/debian etch main non-free contrib deb-src http://ftp.nz.debian.org/debian testing main contrib non-free deb ftp://ftp.nerim.net/debian/ stable main contrib non-free
deb http://ftp.it.debian.org/debian/ etch main contrib non-free deb-src http://ftp.it.debian.org/debian/ etch main contrib non-free deb http://volatile.debian.net/debian-volatile etch/volatile main contrib non-free deb http://security.debian.org/ etch/updates main contrib non-free deb-src http://security.debian.org/ etch/updates main contrib non-free deb http://www.debian-multimedia.org etch main
deb http://ftp.it.debian.org/debian/ lenny main contrib non-free deb-src http://ftp.it.debian.org/debian/ lenny main contrib non-free deb http://volatile.debian.net/debian-volatile lenny/volatile main contrib non-free deb http://security.debian.org/ lenny/updates main contrib non-free
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