On 05/15/2014 08:16 PM, Lennart Poettering wrote: > On Thu, 15.05.14 19:29, Lennart Poettering (lenn...@poettering.net) wrote: > >> On Mon, 12.05.14 20:48, Chris Murphy (li...@colorremedies.com) wrote: >> [...] > > So, as it turns out there's no kernel APi available to check whether a > btrfs raid array is now complete enough for degraded mode to > succeed. There's only a way to check whether it is fully complete. > > And even if we had an API for this, how would this even work at all?
In what this should be different than the normal RAID system ? In both case there are two timeout: the first one is for waiting the full system, the second one is for the minimal set of disks to a degraded mode. If even the second timeout is passed, then we should consider the filesystem not build-able. How it is handle for the RAID system ? Knowing that we should consider to apply the same strategies fro btrfs (may be we need some userspace tool to do that) > mean, just having a catchall switch to boot in degraded mode is really > dangerous if people have more than one array and we might end up > mounting an fs in degraded mode that actually is fully available if we > just waited 50ms longer... > > I mean this is even the problem with just one array: if you have > redundancy of 3 disks, when do you start mounting the thing when > degraded mode is requested on the kernel command line? as soon as > degrdaded mounting is possible (thus fucking up possible all 3 disks > that happened to show up last), or later? > > I have no idea how this all should work really, it's a giant mess. There > probably needs to be some btrfs userspace daemon thing that watches > btrfs arrays and does some magic if they timeout. > > But for now I am pretty sure we should just leave everything in fully > manual mode, that's the safest thing to do... > > Lennart > -- gpg @keyserver.linux.it: Goffredo Baroncelli (kreijackATinwind.it> Key fingerprint BBF5 1610 0B64 DAC6 5F7D 17B2 0EDA 9B37 8B82 E0B5 _______________________________________________ systemd-devel mailing list systemd-devel@lists.freedesktop.org http://lists.freedesktop.org/mailman/listinfo/systemd-devel