What exactly do you mean with by-hash files, perhaps the dep11_by-hash files in /var/cache/apt-cacher/package (I had them before, see above output of -v)? Why do you have files which I don't have? Do I have to configure something special in /etc/apt/apt.conf.d/x for that? The only option I can imagine is that I have disabled caching of packages in /var/cache/apt/archives, as the packages are cached centrally by apt-cacher anyway. However, I do not think this is related.
$ cat /etc/apt/apt.conf.d/01keep-deps # After successfull install by 'apt' the .deb package will be removed from the # cache directory /var/cache/apt/archives by default. This can be changed by # the following configuration option. #Binary::apt::APT::Keep-Downloaded-Packages "true"; # By this the behavior of 'apt-get' is unchanged. The downloaded .deb package # will be kept in the cache directory after it is installed with 'apt-get # install'. To enable the removing behavior for other tools than 'apt' set the # following option. APT::Keep-Downloaded-Packages "false"; $ ls -la /var/cache/apt-cacher/packages drwxr-xr-x 2 www-data www-data 4096 Okt 10 19:31 . drwxr-xr-x 6 www-data www-data 4096 Okt 10 19:31 .. $ apt-get update $ ls -la /var/cache/apt-cacher/packages drwxr-xr-x 2 www-data www-data 4096 Okt 14 23:16 . drwxr-xr-x 6 www-data www-data 4096 Okt 10 19:31 .. -rw-r--r-- 1 www-data www-data 135616 Okt 14 23:16 ftp.de.debian.org_debian_dists_testing_InRelease -rw-r--r-- 1 www-data www-data 25494 Okt 14 23:16 security.debian.org_dists_testing_updates_InRelease The following was necessary, as otherwise only the two above files were downloaded. $ rm -rf /var/cache/apt/*cache.bin $ apt-get update $ ls -la /var/cache/apt-cacher/packages -rw-r--r-- 1 www-data www-data 8284 Okt 14 23:29 ftp.de.debian.org_debian_dists_testing_contrib_dep11_by-hash_SHA256_c4493c9bbb6da0658a815314ed6776192241a4529be750edea7269d4b3b3104e -rw-r--r-- 1 www-data www-data 102860 Okt 14 23:29 ftp.de.debian.org_debian_dists_testing_contrib_dep11_by-hash_SHA256_e26817d903756084ac7d5215205afecac91d9f40c9df0da0663f64a7b6f7096d -rw-r--r-- 1 www-data www-data 135616 Okt 14 23:29 ftp.de.debian.org_debian_dists_testing_InRelease -rw-r--r-- 1 www-data www-data 878 Okt 14 23:29 ftp.de.debian.org_debian_dists_testing_main_binary-amd64_Packages.diff_2017-10-14-2021.08.gz -rw-r--r-- 1 www-data www-data 27910 Okt 14 23:29 ftp.de.debian.org_debian_dists_testing_main_binary-amd64_Packages.diff_by-hash_SHA256_7caccf05e56ae4d753c02810d9f3ddff2e4b043e29dd6dae3f899e15ec66414d -rw-r--r-- 1 www-data www-data 875 Okt 14 23:29 ftp.de.debian.org_debian_dists_testing_main_binary-i386_Packages.diff_2017-10-14-2021.08.gz -rw-r--r-- 1 www-data www-data 27910 Okt 14 23:29 ftp.de.debian.org_debian_dists_testing_main_binary-i386_Packages.diff_by-hash_SHA256_5b692219d1090892f18a0b1d84e5504b72574b94c3167c2bb3625fdb8330b22f -rw-r--r-- 1 www-data www-data 6818124 Okt 14 23:29 ftp.de.debian.org_debian_dists_testing_main_dep11_by-hash_SHA256_6b7c99b0e8f8b08b2b3e156d0c3b4053b2d7f5af5bfab03bfee492248fe35b19 -rw-r--r-- 1 www-data www-data 658 Okt 14 23:29 ftp.de.debian.org_debian_dists_testing_main_i18n_Translation-en.diff_2017-10-14-2021.08.gz -rw-r--r-- 1 www-data www-data 27910 Okt 14 23:29 ftp.de.debian.org_debian_dists_testing_main_i18n_Translation-en.diff_by-hash_SHA256_210c49af092a400efe747dc414330297cd49304ce121a29fda35640d40fc4bab -rw-r--r-- 1 www-data www-data 743 Okt 14 23:29 ftp.de.debian.org_debian_dists_testing_main_source_Sources.diff_2017-10-14-2021.08.gz -rw-r--r-- 1 www-data www-data 27910 Okt 14 23:29 ftp.de.debian.org_debian_dists_testing_main_source_Sources.diff_by-hash_SHA256_6bfd9b104752d28149c67e633ca654b7de9d6fd567ac025425d996b7b4ad66c4 -rw-r--r-- 1 www-data www-data 25494 Okt 14 23:16 security.debian.org_dists_testing_updates_InRelease So is it wise/reliable to depend on files which may be not always present or not up to date because of caching mechanisms of apt-get update? Or is this only a minor initial phenomenon when staring with an emtpy /var/cache/apt-cacher directory? Without the step of removing the *cache.bin files and a following execution of apt-get update, again all packages would be removed by apt-cacher-cleanup-double-patched.pl (I verfied that). Today, as I already have installed all upgrades in the morning, I perform an install of an arbitrary package and not a dist-uprade here. However, this should make no difference. $ apt-get install aria2 $ ls -la /var/cache/apt-cacher/packages drwxr-xr-x 3 www-data www-data 4096 Okt 14 23:34 . drwxr-xr-x 6 www-data www-data 4096 Okt 10 19:31 .. drwxr-xr-x 2 www-data www-data 4096 Okt 14 23:34 ftp.de.debian.org_debian -rw-r--r-- 1 www-data www-data 8284 Okt 14 23:29 ftp.de.debian.org_debian_dists_testing_contrib_dep11_by-hash_SHA256_c4493c9bbb6da0658a815314ed6776192241a4529be750edea7269d4b3b3104e -rw-r--r-- 1 www-data www-data 102860 Okt 14 23:29 ftp.de.debian.org_debian_dists_testing_contrib_dep11_by-hash_SHA256_e26817d903756084ac7d5215205afecac91d9f40c9df0da0663f64a7b6f7096d -rw-r--r-- 1 www-data www-data 135616 Okt 14 23:29 ftp.de.debian.org_debian_dists_testing_InRelease -rw-r--r-- 1 www-data www-data 878 Okt 14 23:29 ftp.de.debian.org_debian_dists_testing_main_binary-amd64_Packages.diff_2017-10-14-2021.08.gz -rw-r--r-- 1 www-data www-data 27910 Okt 14 23:29 ftp.de.debian.org_debian_dists_testing_main_binary-amd64_Packages.diff_by-hash_SHA256_7caccf05e56ae4d753c02810d9f3ddff2e4b043e29dd6dae3f899e15ec66414d -rw-r--r-- 1 www-data www-data 875 Okt 14 23:29 ftp.de.debian.org_debian_dists_testing_main_binary-i386_Packages.diff_2017-10-14-2021.08.gz -rw-r--r-- 1 www-data www-data 27910 Okt 14 23:29 ftp.de.debian.org_debian_dists_testing_main_binary-i386_Packages.diff_by-hash_SHA256_5b692219d1090892f18a0b1d84e5504b72574b94c3167c2bb3625fdb8330b22f -rw-r--r-- 1 www-data www-data 6818124 Okt 14 23:29 ftp.de.debian.org_debian_dists_testing_main_dep11_by-hash_SHA256_6b7c99b0e8f8b08b2b3e156d0c3b4053b2d7f5af5bfab03bfee492248fe35b19 -rw-r--r-- 1 www-data www-data 658 Okt 14 23:29 ftp.de.debian.org_debian_dists_testing_main_i18n_Translation-en.diff_2017-10-14-2021.08.gz -rw-r--r-- 1 www-data www-data 27910 Okt 14 23:29 ftp.de.debian.org_debian_dists_testing_main_i18n_Translation-en.diff_by-hash_SHA256_210c49af092a400efe747dc414330297cd49304ce121a29fda35640d40fc4bab -rw-r--r-- 1 www-data www-data 743 Okt 14 23:29 ftp.de.debian.org_debian_dists_testing_main_source_Sources.diff_2017-10-14-2021.08.gz -rw-r--r-- 1 www-data www-data 27910 Okt 14 23:29 ftp.de.debian.org_debian_dists_testing_main_source_Sources.diff_by-hash_SHA256_6bfd9b104752d28149c67e633ca654b7de9d6fd567ac025425d996b7b4ad66c4 -rw-r--r-- 1 www-data www-data 25494 Okt 14 23:16 security.debian.org_dists_testing_updates_InRelease $ ls -la /var/cache/apt-cacher/packages/ftp.de.debian.org_debian drwxr-xr-x 2 www-data www-data 4096 Okt 14 23:34 . drwxr-xr-x 3 www-data www-data 4096 Okt 14 23:34 .. -rw-r--r-- 1 www-data www-data 1210410 Okt 14 23:34 aria2_1.32.0-1_amd64.deb $ /tmp/apt-cacher-cleanup-double-patched.pl -v Invoked as root, changing to www-data:www-data and re-execing. Checking for ftp.de.debian.org_debian_dists_testing_main_binary-amd64_Packages{,.gz,.xz,.bz2} for ftp.de.debian.org_debian_dists_testing_main_binary-amd64_Packages.diff_by-hash_SHA256_7caccf05e56ae4d753c02810d9f3ddff2e4b043e29dd6dae3f899e15ec66414d Checking for ftp.de.debian.org_debian_dists_testing_main_binary-i386_Packages{,.gz,.xz,.bz2} for ftp.de.debian.org_debian_dists_testing_main_binary-i386_Packages.diff_by-hash_SHA256_5b692219d1090892f18a0b1d84e5504b72574b94c3167c2bb3625fdb8330b22f Checking for ftp.de.debian.org_debian_dists_testing_main_i18n_Translation-en{,.gz,.xz,.bz2} for ftp.de.debian.org_debian_dists_testing_main_i18n_Translation-en.diff_by-hash_SHA256_210c49af092a400efe747dc414330297cd49304ce121a29fda35640d40fc4bab Checking for ftp.de.debian.org_debian_dists_testing_main_source_Sources{,.gz,.xz,.bz2} for ftp.de.debian.org_debian_dists_testing_main_source_Sources.diff_by-hash_SHA256_6bfd9b104752d28149c67e633ca654b7de9d6fd567ac025425d996b7b4ad66c4 Get /ftp.de.debian.org/debian/dists/testing/main/i18n/Translation-en.xz Get /ftp.de.debian.org/debian/dists/testing/main/i18n/Translation-en.gz Get /ftp.de.debian.org/debian/dists/testing/main/i18n/Translation-en.bz2 Get /ftp.de.debian.org/debian/dists/testing/main/source/Sources.xz Get /ftp.de.debian.org/debian/dists/testing/main/binary-amd64/Packages.xz Get /ftp.de.debian.org/debian/dists/testing/main/binary-i386/Packages.xz Get /ftp.de.debian.org/debian/dists/testing/InRelease Cached file ftp.de.debian.org_debian_dists_testing_contrib_dep11_by-hash_SHA256_e26817d903756084ac7d5215205afecac91d9f40c9df0da0663f64a7b6f7096d is current by-hash file referenced in ftp.de.debian.org_debian_dists_testing_InRelease. Adding to list for parsing Cached file ftp.de.debian.org_debian_dists_testing_main_binary-i386_Packages.diff_by-hash_SHA256_5b692219d1090892f18a0b1d84e5504b72574b94c3167c2bb3625fdb8330b22f is current by-hash file referenced in ftp.de.debian.org_debian_dists_testing_InRelease. Adding to list for parsing Cached file ftp.de.debian.org_debian_dists_testing_main_binary-amd64_Packages.diff_by-hash_SHA256_7caccf05e56ae4d753c02810d9f3ddff2e4b043e29dd6dae3f899e15ec66414d is current by-hash file referenced in ftp.de.debian.org_debian_dists_testing_InRelease. Adding to list for parsing Cached file ftp.de.debian.org_debian_dists_testing_contrib_dep11_by-hash_SHA256_c4493c9bbb6da0658a815314ed6776192241a4529be750edea7269d4b3b3104e is current by-hash file referenced in ftp.de.debian.org_debian_dists_testing_InRelease. Adding to list for parsing Cached file ftp.de.debian.org_debian_dists_testing_main_i18n_Translation-en.diff_by-hash_SHA256_210c49af092a400efe747dc414330297cd49304ce121a29fda35640d40fc4bab is current by-hash file referenced in ftp.de.debian.org_debian_dists_testing_InRelease. Adding to list for parsing Cached file ftp.de.debian.org_debian_dists_testing_main_source_Sources.diff_by-hash_SHA256_6bfd9b104752d28149c67e633ca654b7de9d6fd567ac025425d996b7b4ad66c4 is current by-hash file referenced in ftp.de.debian.org_debian_dists_testing_InRelease. Adding to list for parsing Cached file ftp.de.debian.org_debian_dists_testing_main_dep11_by-hash_SHA256_6b7c99b0e8f8b08b2b3e156d0c3b4053b2d7f5af5bfab03bfee492248fe35b19 is current by-hash file referenced in ftp.de.debian.org_debian_dists_testing_InRelease. Adding to list for parsing Get /ftp.de.debian.org/debian/dists/testing/main/binary-amd64/Packages.xz Get /ftp.de.debian.org/debian/dists/testing/main/binary-i386/Packages.xz Get /ftp.de.debian.org/debian/dists/testing/main/source/Sources.xz Get /security.debian.org/dists/testing/updates/InRelease Reading: ftp.de.debian.org_debian_dists_testing_InRelease Reading: ftp.de.debian.org_debian_dists_testing_contrib_dep11_by-hash_SHA256_c4493c9bbb6da0658a815314ed6776192241a4529be750edea7269d4b3b3104e Reading: ftp.de.debian.org_debian_dists_testing_contrib_dep11_by-hash_SHA256_e26817d903756084ac7d5215205afecac91d9f40c9df0da0663f64a7b6f7096d Reading: ftp.de.debian.org_debian_dists_testing_main_binary-amd64_Packages.diff_by-hash_SHA256_7caccf05e56ae4d753c02810d9f3ddff2e4b043e29dd6dae3f899e15ec66414d Reading: ftp.de.debian.org_debian_dists_testing_main_binary-amd64_Packages.xz Reading: ftp.de.debian.org_debian_dists_testing_main_binary-i386_Packages.diff_by-hash_SHA256_5b692219d1090892f18a0b1d84e5504b72574b94c3167c2bb3625fdb8330b22f Reading: ftp.de.debian.org_debian_dists_testing_main_binary-i386_Packages.xz Reading: ftp.de.debian.org_debian_dists_testing_main_dep11_by-hash_SHA256_6b7c99b0e8f8b08b2b3e156d0c3b4053b2d7f5af5bfab03bfee492248fe35b19 Reading: ftp.de.debian.org_debian_dists_testing_main_i18n_Translation-en.diff_by-hash_SHA256_210c49af092a400efe747dc414330297cd49304ce121a29fda35640d40fc4bab Reading: ftp.de.debian.org_debian_dists_testing_main_source_Sources.diff_by-hash_SHA256_6bfd9b104752d28149c67e633ca654b7de9d6fd567ac025425d996b7b4ad66c4 Reading: ftp.de.debian.org_debian_dists_testing_main_source_Sources.xz Reading: security.debian.org_dists_testing_updates_InRelease Found 158132 valid file entries Building source package file/version table Validating ftp.de.debian.org_debian_dists_testing_contrib_dep11_by-hash_SHA256_c4493c9bbb6da0658a815314ed6776192241a4529be750edea7269d4b3b3104e Get http://ftp.de.debian.org/debian/dists/testing/contrib/dep11/by-hash/SHA256/c4493c9bbb6da0658a815314ed6776192241a4529be750edea7269d4b3b3104e Validating ftp.de.debian.org_debian_dists_testing_contrib_dep11_by-hash_SHA256_e26817d903756084ac7d5215205afecac91d9f40c9df0da0663f64a7b6f7096d Get http://ftp.de.debian.org/debian/dists/testing/contrib/dep11/by-hash/SHA256/e26817d903756084ac7d5215205afecac91d9f40c9df0da0663f64a7b6f7096d Removing file: ftp.de.debian.org_debian_dists_testing_main_binary-amd64_Packages.diff_2017-10-14-2021.08.gz and company... Validating ftp.de.debian.org_debian_dists_testing_main_binary-amd64_Packages.diff_by-hash_SHA256_7caccf05e56ae4d753c02810d9f3ddff2e4b043e29dd6dae3f899e15ec66414d Get http://ftp.de.debian.org/debian/dists/testing/main/binary-amd64/Packages.diff/by-hash/SHA256/7caccf05e56ae4d753c02810d9f3ddff2e4b043e29dd6dae3f899e15ec66414d Removing file: ftp.de.debian.org_debian_dists_testing_main_binary-i386_Packages.diff_2017-10-14-2021.08.gz and company... Validating ftp.de.debian.org_debian_dists_testing_main_binary-i386_Packages.diff_by-hash_SHA256_5b692219d1090892f18a0b1d84e5504b72574b94c3167c2bb3625fdb8330b22f Get http://ftp.de.debian.org/debian/dists/testing/main/binary-i386/Packages.diff/by-hash/SHA256/5b692219d1090892f18a0b1d84e5504b72574b94c3167c2bb3625fdb8330b22f Validating ftp.de.debian.org_debian_dists_testing_main_dep11_by-hash_SHA256_6b7c99b0e8f8b08b2b3e156d0c3b4053b2d7f5af5bfab03bfee492248fe35b19 Get http://ftp.de.debian.org/debian/dists/testing/main/dep11/by-hash/SHA256/6b7c99b0e8f8b08b2b3e156d0c3b4053b2d7f5af5bfab03bfee492248fe35b19 Removing file: ftp.de.debian.org_debian_dists_testing_main_i18n_Translation-en.diff_2017-10-14-2021.08.gz and company... Validating ftp.de.debian.org_debian_dists_testing_main_i18n_Translation-en.diff_by-hash_SHA256_210c49af092a400efe747dc414330297cd49304ce121a29fda35640d40fc4bab Get http://ftp.de.debian.org/debian/dists/testing/main/i18n/Translation-en.diff/by-hash/SHA256/210c49af092a400efe747dc414330297cd49304ce121a29fda35640d40fc4bab Removing file: ftp.de.debian.org_debian_dists_testing_main_source_Sources.diff_2017-10-14-2021.08.gz and company... Validating ftp.de.debian.org_debian_dists_testing_main_source_Sources.diff_by-hash_SHA256_6bfd9b104752d28149c67e633ca654b7de9d6fd567ac025425d996b7b4ad66c4 Get http://ftp.de.debian.org/debian/dists/testing/main/source/Sources.diff/by-hash/SHA256/6bfd9b104752d28149c67e633ca654b7de9d6fd567ac025425d996b7b4ad66c4 $ ls -la /var/cache/apt-cacher/packages/ftp.de.debian.org_debian drwxr-xr-x 2 www-data www-data 4096 Okt 14 23:34 . drwxr-xr-x 3 www-data www-data 4096 Okt 14 23:39 .. -rw-r--r-- 1 www-data www-data 1210410 Okt 14 23:34 aria2_1.32.0-1_amd64.deb Wow, seams that first cleaning the apt *cache.bin files to collect all need index/hash files from the repo anew, so that apt-cacher could cache it, and your patches did the job! What/why did the behavior change that makes your patches necessary, although some time ago all was working well? Questions over questions. Now I tried it directly with the original version, just for the fun of it: $ /usr/share/apt-cacher/apt-cacher-cleanup.pl -v Invoked as root, changing to www-data:www-data and re-execing. checking for ftp.de.debian.org_debian_dists_testing_{In,}Release for ftp.de.debian.org_debian_dists_testing_main_binary-amd64_Packages.xz Found ftp.de.debian.org_debian_dists_testing_InRelease checking for ftp.de.debian.org_debian_dists_testing_{In,}Release for ftp.de.debian.org_debian_dists_testing_main_binary-i386_Packages.xz Found ftp.de.debian.org_debian_dists_testing_InRelease checking for ftp.de.debian.org_debian_dists_testing_{In,}Release for ftp.de.debian.org_debian_dists_testing_main_source_Sources.xz Found ftp.de.debian.org_debian_dists_testing_InRelease Get /ftp.de.debian.org/debian/dists/testing/InRelease Get /ftp.de.debian.org/debian/dists/testing/main/binary-amd64/Packages.xz Get /ftp.de.debian.org/debian/dists/testing/main/binary-i386/Packages.xz Get /ftp.de.debian.org/debian/dists/testing/main/source/Sources.xz Get /security.debian.org/dists/testing/updates/InRelease Reading: ftp.de.debian.org_debian_dists_testing_InRelease Reading: ftp.de.debian.org_debian_dists_testing_main_binary-amd64_Packages.xz Reading: ftp.de.debian.org_debian_dists_testing_main_binary-i386_Packages.xz Reading: ftp.de.debian.org_debian_dists_testing_main_source_Sources.xz Reading: security.debian.org_dists_testing_updates_InRelease Found 158055 valid file entries Building source package file/version table Validating ftp.de.debian.org_debian_dists_testing_contrib_dep11_by-hash_SHA256_c4493c9bbb6da0658a815314ed6776192241a4529be750edea7269d4b3b3104e Get http://ftp.de.debian.org/debian/dists/testing/contrib/dep11/by-hash/SHA256/c4493c9bbb6da0658a815314ed6776192241a4529be750edea7269d4b3b3104e Validating ftp.de.debian.org_debian_dists_testing_contrib_dep11_by-hash_SHA256_e26817d903756084ac7d5215205afecac91d9f40c9df0da0663f64a7b6f7096d Get http://ftp.de.debian.org/debian/dists/testing/contrib/dep11/by-hash/SHA256/e26817d903756084ac7d5215205afecac91d9f40c9df0da0663f64a7b6f7096d Validating ftp.de.debian.org_debian_dists_testing_main_binary-amd64_Packages.diff_by-hash_SHA256_7caccf05e56ae4d753c02810d9f3ddff2e4b043e29dd6dae3f899e15ec66414d Get http://ftp.de.debian.org/debian/dists/testing/main/binary-amd64/Packages.diff/by-hash/SHA256/7caccf05e56ae4d753c02810d9f3ddff2e4b043e29dd6dae3f899e15ec66414d Validating ftp.de.debian.org_debian_dists_testing_main_binary-i386_Packages.diff_by-hash_SHA256_5b692219d1090892f18a0b1d84e5504b72574b94c3167c2bb3625fdb8330b22f Get http://ftp.de.debian.org/debian/dists/testing/main/binary-i386/Packages.diff/by-hash/SHA256/5b692219d1090892f18a0b1d84e5504b72574b94c3167c2bb3625fdb8330b22f Validating ftp.de.debian.org_debian_dists_testing_main_dep11_by-hash_SHA256_6b7c99b0e8f8b08b2b3e156d0c3b4053b2d7f5af5bfab03bfee492248fe35b19 Get http://ftp.de.debian.org/debian/dists/testing/main/dep11/by-hash/SHA256/6b7c99b0e8f8b08b2b3e156d0c3b4053b2d7f5af5bfab03bfee492248fe35b19 Validating ftp.de.debian.org_debian_dists_testing_main_i18n_Translation-en.diff_by-hash_SHA256_210c49af092a400efe747dc414330297cd49304ce121a29fda35640d40fc4bab Get http://ftp.de.debian.org/debian/dists/testing/main/i18n/Translation-en.diff/by-hash/SHA256/210c49af092a400efe747dc414330297cd49304ce121a29fda35640d40fc4bab Validating ftp.de.debian.org_debian_dists_testing_main_source_Sources.diff_by-hash_SHA256_6bfd9b104752d28149c67e633ca654b7de9d6fd567ac025425d996b7b4ad66c4 Get http://ftp.de.debian.org/debian/dists/testing/main/source/Sources.diff/by-hash/SHA256/6bfd9b104752d28149c67e633ca654b7de9d6fd567ac025425d996b7b4ad66c4 $ ls -la /var/cache/apt-cacher/packages/ftp.de.debian.org_debian drwxr-xr-x 2 www-data www-data 4096 Okt 14 23:34 . drwxr-xr-x 3 www-data www-data 4096 Okt 14 23:39 .. -rw-r--r-- 1 www-data www-data 1210410 Okt 14 23:34 aria2_1.32.0-1_amd64.deb Now things are getting curious. Why does it now not delete the package anymore? Maybe somehow I have all/the right index files now. How can I ensure that in future, e.g., by something like a --force parameter for apt-get update? Why should I not have had the right index files for weeks before? Finally, just some of my thoughts on the game: How gets apt-get clean its similar job done for the package cache in /var/cache/apt/archives? The necessity of removing the *cache.bin files before apt-get update stems from the fact that for the index/hash data there is always a two level caching. When there is a hit in the inner cache (apt), the outer one is not updated (apt-cacher). Chris