Dne 02. 06. 20 v 19:26 Richard W.M. Jones napsal(a): > On Tue, Jun 02, 2020 at 12:44:17PM +0200, Florian Weimer wrote: >> * Panu Matilainen: >> >>> Lets start with the basics: >>> - is sqlite even involved - it will only be used on rawhide builds if >>> mock bootstrap is used >>> - does it make a difference if you override _db_backend to bdb/sqlite >>> from mock config / cli define >>> - a reproducer please (eg, what package is considerably slower to >>> build than before, and by how much) >> And: Does the difference reproduce when building on tmpfs? > Good time to say that you can use an NBD loopback to mock-build either > on a userspace ramdisk or backed by a disk but discarding flush > requests. The performance is indistinguishable from tmpfs (and much > more flexible in other ways). I did some benchmarking a couple of > weeks ago: > > https://www.redhat.com/archives/libguestfs/2020-May/msg00053.html > https://www.redhat.com/archives/libguestfs/2020-May/msg00074.html > > Easy set up is: > > # rm -f /tmp/sock > # nbdkit -U /tmp/sock memory 100G > # nbd-client -b 512 -unix /tmp/sock /dev/nbd0 -connections 4 > # mkfs.xfs /dev/nbd0 > # mount /dev/nbd0 /var/lib/mock > > or using http://libguestfs.org/nbdkit-tmpdisk-plugin.1.html: > > # rm -f /tmp/sock > # nbdkit -U /tmp/sock tmpdisk size=100G > # nbd-client -b 512 -unix /tmp/sock /dev/nbd0 -connections 1 > # mount /dev/nbd0 /var/lib/mock > > or (requires bleeding edge nbdkit): > > # rm -f /tmp/sock > # lvcreate -L 100G -n tmp /dev/fedora > # nbdkit -U /tmp/socket --filter=fua fuamode=discard file /dev/fedora/tmp > # nbd-client -b 512 -unix /tmp/sock /dev/nbd0 -connections 4 > # mkfs.xfs /dev/nbd0 > # mount /dev/nbd0 /var/lib/mock > > Rich. >
NBD kit is definitely interesting piece of technology, but I think there is missing quite a bit to be as easy as you say and there is definitely a lot of missing information, e.g. does the setup persist reboots? It would be probably more interesting, if it was mock plugin the same way tmpfs or lvm plugins are. Vít _______________________________________________ devel mailing list -- devel@lists.fedoraproject.org To unsubscribe send an email to devel-le...@lists.fedoraproject.org Fedora Code of Conduct: https://docs.fedoraproject.org/en-US/project/code-of-conduct/ List Guidelines: https://fedoraproject.org/wiki/Mailing_list_guidelines List Archives: https://lists.fedoraproject.org/archives/list/devel@lists.fedoraproject.org
