On Fri, 22 Nov 2024 at 22:56, Johannes Schauer Marin Rodrigues
<jo...@debian.org> wrote:
> Quoting Richard Lewis (2024-11-22 23:14:48)
> > It shows time is lost throughout,
> > I suppose i will try and make a larger tmpfs to use.
I remounted /dev/shm larger, it helped, a bit
> could it be that your schroot is faster because the overlayfs you mount in
> your
> directory-based schroot comes from a tmpfs and not from your disk?
this might be it - or maybe how overlayfs works is equivalent to that
(one of the things i like about unshare is that it's a lot easier to
understand what is going on!)
when i open a schroot session i see it mounts things under /run (which
is a tmpfs) and under /var/lib (which is ext4)
(from findmnt --output TARGET,FSTYPE --notruncate):
─/run
tmpfs
│
└─/run/schroot/mount/unstable-amd64-sbuild-76deacf6-fa8a-423b-a797-f4945e3ae74c
overlay
│
├─/run/schroot/mount/unstable-amd64-sbuild-76deacf6-fa8a-423b-a797-f4945e3ae74c/proc
proc
│
├─/run/schroot/mount/unstable-amd64-sbuild-76deacf6-fa8a-423b-a797-f4945e3ae74c/sys
sysfs
│
├─/run/schroot/mount/unstable-amd64-sbuild-76deacf6-fa8a-423b-a797-f4945e3ae74c/dev/pts
devpts
│
├─/run/schroot/mount/unstable-amd64-sbuild-76deacf6-fa8a-423b-a797-f4945e3ae74c/dev/shm
tmpfs
│
└─/run/schroot/mount/unstable-amd64-sbuild-76deacf6-fa8a-423b-a797-f4945e3ae74c/build
ext4
└─/var/lib/schroot/union/underlay/unstable-amd64-sbuild-76deacf6-fa8a-423b-a797-f4945e3ae74c
ext4
the main overlay thing has the following mount options
rw,relatime,
lowerdir=/var/lib/schroot/union/underlay/unstable-amd64-sbuild-76deacf6-fa8a-423b-a797-f4945e3ae74c,
upperdir=/var/lib/schroot/union/overlay/unstable-amd64-sbuild-76deacf6-fa8a-423b-a797-f4945e3ae74c/upper,
workdir=/var/lib/schroot/union/overlay/unstable-amd64-sbuild-76deacf6-fa8a-423b-a797-f4945e3ae74c/work
/var is ext4
i dont know if relatime could have some advantages?
