> On 10 Aug 2022, at 21:10, Lennart Poettering <lennart@xxxxxxxxxxxxxx> wrote: > > On Mi, 10.08.22 10:13, Thomas Archambault (toma@xxxxxxxxxxxxxxxxx) wrote: > >> Thank you again Lennart, and thx Kevin. >> >> That makes total sense, and accounts for the application's high level >> start-up delay which appears to be what we are stuck with if we are over >> xfs. Unfortunately, it's difficult to dictate to the client to change their >> fs type, consequently we can't develop / ship a tool with that baseline >> latency on our primary target platform (RHEL xx.) >> >> So the next obvious question would be, is XFS reflink support on the >> systemd-nspawn roadmap or actually, (and even better) has support been >> incorporated already in the latest and greatest src and I'm just behind the >> curve working with the older version of nspawn as shipped in RHEL90? >> >> I'm asking because according to the RHEL 9 docs (https://access.redhat.com/documentation/en-us/red_hat_enterprise_linux/9/html-single/managing_file_systems/index#the-xfs-file-system_assembly_overview-of-available-file-systems) >> it's the current default fs and is configured for "Reflink-based file >> copies." > > We issue copy_file_range() syscall, which should do reflinks on xfs, > if it supports that. Question is if your kernel supports that too. I > have no experience with xfs though, no idea how xfs hooked up reflink > initially. And we never tested that really. I don't think outside RHEL > many people use xfs. Isn’t XFS the default for fedora server? Barry > > If you provide a more complete strace output, you should see the > copy_file_range() stuff there. > > Lennart > > -- > Lennart Poettering, Berlin >