Тупой emerge --metadata

# Sync all overlays
*

# Regenerate overlay metadata
@emerge --regen || true

# cat /etc/eix-sync.conf 
# Sync overlays
*

# Transfer metadata cache if FEATURES="metadata-transfer" is enabled
@emerge --metadata

# Regenerate overlay metadata
@emerge --regen --quiet

The following cache methods are available:
...

              sqlite This is an extremely fast cache method if you are using portage with the sqlite  backend,
                     see http://en.gentoo-wiki.com/wiki/Portage_SQLite_Cache (originally this was described in
                     http://gentoo-wiki.com/TIP_speed_up_portage_with_sqlite which might be  still  accessible
                     at  http://gentoo-wiki.info/TIP_speed_up_portage_with_sqlite).   Note that in contrast to
                     the default metadata cache method you must use emerge --metadata  before  you  call  eix-
                     update with this method.

       --metadata
              Transfers metadata cache from ${PORTDIR}/metadata/md5-cache/ to /var/cache/edb/dep/ as  is  nor‐
              mally  done  on the tail end of an rsync update using emerge --sync.  This process populates the
              cache database that portage uses for pre-parsed lookups of package data.  It does  not  populate
              cache  for the overlays listed in PORTDIR_OVERLAY.  In order to generate cache for overlays, use
              --regen.  In versions of portage >=2.1.5 the --metadata action is totally unnecessary unless the
              user has enabled FEATURES="metadata-transfer" in make.conf(5).

              metadata-transfer
                     Automatically  perform  a  metadata transfer when `emerge --sync` is run.  In versions of
                     portage >=2.1.5, this feature is disabled by default. When metadata-transfer is disabled,
                     metadata  cache  from  the ${PORTDIR}/metadata/md5-cache/ directory will be used directly
                     (if available).

app-portage/eix-0.29.3 "... sqlite ..." 

PORTDIR_CACHE_METHOD='sqlite'
OVERLAY_CACHE_METHOD='parse'

FEATURES="${FEATURES} parallel-fetch distcc"

# ls -la /var/cache/edb/dep/usr/
итого 47466
drwxrwsr-x 4 root portage      128 авг.  17 01:29 .
drwxrwsr-x 4 root portage       96 марта 30 22:22 ..
drwxrwsr-x 3 root portage      104 авг.   2 23:54 local
drwxrwsr-x 2 root portage       48 марта 30 22:22 portage
-rw-rw-r-- 1 root portage 48555008 авг.  17 01:29 portage.sqlite

total 47124
drwxrwsr-x 4 root portage     4096 Aug 15 11:08 .
drwxrwsr-x 4 root portage     4096 May 16 23:53 ..
drwxrwsr-x 3 root portage     4096 Aug 10 00:07 local
drwxrwsr-x 2 root portage     4096 May 16 23:53 portage
-rw-rw-r-- 1 root portage 48233472 Aug 15 11:08 portage.sqlite

OVERLAY_CACHE_METHOD="sqlite"

# cat /etc/portage/env/app-portage/eix 
post_src_configure() {
        # Default remote path 1 for eix-remote
        REMOTE_PATH="http://dev.gentooexperimental.org/eix_cache/eix-caches.tbz2"
        econf --with-remote-path1=${REMOTE_PATH}
}

WarnOrDie() {
        [ -z "${FATAL_HOOKS:++}" ] || die "${@}"
        ewarn "${@}"
}

DoExecute() {
        for curr_cmd
        do      set +f
                eval "${curr_cmd}" || WarnOrDie "`eval_gettext \
                        'Something went wrong with ${curr_cmd}'`"
        done
}