Am 03.01.25 um 00:36 schrieb Ángel:
On 2025-01-02 at 17:11 +0300, Michael Tokarev wrote:
02.01.2025 03:00, Aurélien COUDERC wrote:
Sure but I wouldn’t know how to do that since I’m calling apt and
force-unsafe-io seems to be a dpkg option ?
echo force-unsafe-io > /etc/dpkg/dpkg.conf.d/unsafeio
before upgrade.
/mjt
Beware: this should actually be
echo force-unsafe-io > /etc/dpkg/dpkg.cfg.d/unsafeio
:)
Out of curiosity I've made a benchmark of my own. In my experience you
hardly notice slowdown on desktop machines with modern NVMe drives, but
you notice it on bad storage. I.e. I just happen to have a small (3 old
nodes, 9 osd with cheap SSD) old CEPH cluster at hand and a bookworm VM
with 42 pending updates on it. Small 2 vCPU/2GB RAM VM. Snapshotted
after downloading all packages locally.
Shared infrastructure of course. Note that this includes an update of
the initramfs, which is CPU bound and takes a bit on this system. You
can take around 45s off the clock for the initramfs regeneration in each
run. I did a couple of runs and the results were pretty consistent.
/dev/mapper/proxy1-root on / type ext4 (rw,relatime,errors=remount-ro)
time apt -y dist-upgrade; time sync
The following packages will be upgraded:
base-files bsdextrautils bsdutils distro-info-data initramfs-tools
initramfs-tools-core iputils-ping libblkid1 libc-bin libc-l10n libc6
libcurl3-gnutls libfdisk1 libglib2.0-0 libglib2.0-data
libmount1 libnghttp2-14 libnss-systemd libpam-systemd libpython3.11
libpython3.11-minimal libpython3.11-stdlib libsmartcols1 libsqlite3-0
libssl3 libsystemd-shared libsystemd0 libudev1
libuuid1 locales locales-all mount nscd openssl python3.11
python3.11-minimal systemd systemd-sysv udev util-linux util-linux-extra
util-linux-locales
Default settings:
real 1m50.451s
user 0m52.333s
sys 0m33.574s
real 0m0.236s
user 0m0.007s
sys 0m0.001s
force-unsafe-io
real 1m47.309s
user 0m52.072s
sys 0m32.334s
real 0m0.324s
user 0m0.005s
sys 0m0.001s
eatmydata
real 1m36.407s
user 0m51.810s
sys 0m34.764s
real 0m0.334s
user 0m0.001s
sys 0m0.010s
So removing the time needed for the initramfs we have around 65s
unchanged vs. 62s with force-unsafe-io vs. 51s with eatmydata. Or, < 5%
speedup with force-unsafe-io on this system.
I have the snapshot still at hand, if there are other options you'd like
to test drop me a note.
Bernhard
