On 2022-10-14 11:59:09 +0200, Marco d'Itri wrote: > On Oct 14, Vincent Lefevre <vinc...@vinc17.net> wrote: > > > The /etc/fstab file is created using by default ext4 with just > > the errors=remount-ro option. However, the Debian FAQ recommends > > the nodelalloc mount option to avoid performance degradation and > > preserve data safety: > This is not "the Debian FAQ" but "the DPKG FAQ", which has been known to > recommend awful things in the past.
But it is still considered in the present times by the dpkg developers. Bug 923423 was closed several hours ago based on this dpkg FAQ: ------------------------------------------------------------------------ All these fsync()s you see in rapid succession are used as a synchronization points, way after the data has been requested to be synced to disk asynchronously via sync_file_range(). What this is trying to achieve is durability, so that dpkg can know the data is on the disk, so that it can mark the package as installed. This is explained on the dpkg FAQ: <https://wiki.debian.org/Teams/Dpkg/FAQ#Q:_Why_is_dpkg_so_slow_when_using_new_filesystems_such_as_btrfs_or_ext4.3F> ------------------------------------------------------------------------ (the issue here is that there is a fsync for *every* file, so that for a package with many small files, such as texlive-fonts-extra, which currently has more than 92000 files, this can be awfully slow). -- Vincent Lefèvre <vinc...@vinc17.net> - Web: <https://www.vinc17.net/> 100% accessible validated (X)HTML - Blog: <https://www.vinc17.net/blog/> Work: CR INRIA - computer arithmetic / AriC project (LIP, ENS-Lyon)
