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    SubjectBoot regression caused by commit 6829a048
    Hi all,

    I've noticed a boot regression caused by commit 6829a048 ("NFS: Retry
    mounting NFSROOT") which has increased boot time by 95 seconds.

    The scenario is as follows:
    - A virtual guest running under the KVM tool.
    - Guest is using kernel automatic IP DHCP configuration ("ip=dhcp").
    - Guest is booting from a 9p device (which is not detected as block,
    and gets mounted after NFS tries to do its mounts).
    - No NFS server at all, no NFS parameters passed to the guest kernel.

    Under this scenario, theres an additional 95 second delay before NFS
    fails and tries to boot using 9p:

    [ 6.505269] md: autorun ...
    [ 6.506954] md: ... autorun DONE.
    [ 101.522716] VFS: Unable to mount root fs via NFS, trying floppy.
    [ 101.534499] VFS: Mounted root (9p filesystem) on device 0:18.

    This probably happens since the NFS server isn't configured, so the
    bootserver is automatically assumed to be the DHCP server, and with the
    commit above we won't simply fail immediately when the NFS code fails
    connecting to it.

    I'm not quite sure about the correct solution for this. While I can
    forcefully disable NFS, is it really the right solution? Should we be
    retrying a NFS server even if one wasn't specifically set?




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      Last update: 2012-01-06 18:35    [W:0.019 / U:8.456 seconds]
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