On 24/12/24 10:54, Michael Tokarev wrote:
Today, doing an fsync() really hurts, - with SSDs/flash it reduces
the lifetime of the storage, for many modern filesystems it is a
costly operation which bloats the metadata tree significantly,
resulting in all further operations becomes inefficient.
How about turning this option - force-unsafe-io - to on by default
in 2025? That would be a great present for 2025 New Year! :)
There is a possible related, but independent, optimization that has the
chance to significantly reduce dpkg install's time up to 90%.
There is PoC patch [1,2] to teach dpkg to reflink files from data.tar
instead of copying them. With no changes in semantics or FS operations,
the time to install big packages like linux-firmware goes down from 39
seconds to 6 seconds. The use of reflink would have no adverse
consequences for users of ext4, but it would greatly speed up package
installation on XFS, btrfs and (in some cases) ZFS.
[1] https://bugs.debian.org/1086976
[2] https://github.com/teknoraver/dpkg/compare/main...cow
Regards,
--
Gioele Barabucci
