Hello Dave,
Dave Martin [2010-08-09 9:48 +0100]:
Fortunately fragmentation is not a problem: tar --delete squashes the deleted entry out of the file by rewriting the entire file contents from the point where the deletion occurred ;) Of course, that could be a bit slow, especially if you delete something near the start of the archive...
Ah, right. I take it that rules out having one big tarball for /usr/share/doc/ then?
On Fri, Aug 6, 2010 at 7:50 PM, Loïc Minier loic.minier@linaro.org wrote: [...]
Yup, Martin Pitt worked on some APT patches to allow keeping these compressed in the local disk.
Out of interest, since these indexes are designed to be used via mmap,
They aren't. apt only read()s /var/lib/apt/lists/*. It only mmaps some dpkg files (/var/lib/dpkg/status, I think) and it's internal cache (/var/cache/apt/pkgcache.bin).
do we need to decompress the files when running apt?
Only dynamically in memory when building pkgcache.bin. But that doesn't change the RAM footprint, since without compression it would also read the entire file into RAM while doing that.
Martin