[tz] Looking for a way to cut down binary zoneinfo size. Does anyone have the way to?

Paul.Koning at dell.com Paul.Koning at dell.com
Thu May 18 17:39:39 UTC 2017

> On May 18, 2017, at 1:29 PM, Arthur David Olson <arthurdavidolson at gmail.com> wrote:
> Cutting out old data may not buy as much as you'd like. Putting a "timecnt = 0" at the top of "writezone" in "zic.c" and then comparing the produced directories of the original ("tzraw") and modified ("tzcooked") yields:
>     Script started on Thu, May 18, 2017  1:12:37 PM
>     $ du -s tzraw/tmp/etc tzcooked/tmp/etc
>     3103    tzraw/tmp/etc
>     2356    tzcooked/tmp/etc
>     $ exit
>     exit
>     Script done on Thu, May 18, 2017  1:12:49 PM
> Limited savings is due to disk sector size; as an example, the "America/New_York" produced by an unmodified zic weighs in at 3545 bytes; on a 4096-byte-sector system, the one sector it takes can't be reduced.
> (Your correspondent is enough of a fossil to have lived in the age of 512-byte sectors.)
> If space is at a premium, be sure to "make REDO=posix_only ..." when building.
>     @dashdashado

That's a point.  Note though that removing old information will also make for a bunch of duplicates, which reduces the total storage needed.  Also, if you can use a storage system that packs the data, the sector issue may not be there.  I could imagine, for example, storing the zone data in a zip file and extracting the desired file when the user says "I want to use zone America/Thule".  In our own case, I used a dense file system similar to Linux's "romfs".


More information about the tz mailing list