Tips: Saving local disk space when cloning (original) (raw)

Aleksey Shipilev ashipile at redhat.com
Wed Nov 22 14:48:04 UTC 2017

On 11/22/2017 10:15 AM, Magnus Ihse Bursie wrote:

I'd like to propagate a tips I got from Erik. If you have a recent enough mercurial, you can save some significant local disk space by applying Mercurials "aggressive merge" algorithm when cloning. This brings down the .hg directory from 1.6 GB to 1.1 GB. While disk is cheap these days, SSD:s on laptops are still quite limited (at least mine is!), and if you have multiple repos cloned, these gigabytes add up. The only downside is that the conversion takes quite some time (~1 hour).

To achieve this, use the following command line when cloning: hg --config=format.generaldelta=1 --config=format.aggressivemergedeltas=1 clone --pull http://hg.openjdk.java.net/jdk/jdk jdk Apparently there were some technical reasons why this could not been enabled by default on our hg.openjdk.java.net server. :-( But at least you can apply this for yourself, if disk space is a premium.

Very nice trick, thanks! You can do the same with pre-jdk10 builds, with:

$ HGFOREST_GLOBALOPTS=" --config=format.generaldelta=1 --config=format.aggressivemergedeltas=1"
sh common/bin/hgforest.sh clone

This cuts down both workspace and compressed tarball sizes quite significantly. E.g. workspace tarballs at https://builds.shipilev.net/workspaces/ are now 50-300 MB lighter.

-Aleksey

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