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instance boot halting for few minutes

asked 2018-05-11 10:24:51 -0500

Damian Dąbrowski gravatar image


Every time when i boot or hard reboot server(problem doesn't occur on soft reboot), instance is on "active" state, but for system boot i need to wait few minutes. What i see in VNC depends on used image:

  • for ubuntu cloud image i see "booting from Hard Disk..."
  • for debian cloud image i see "booting from Hard Disk.." and below "SYSLINUX 6.03 EED[...]"
  • for ubuntu server install ISO i see blank purple screen

Few facts:

  • when machine finally starts i don't see any unstable IO, all works fine
  • I'm using openstack with ceph backend for cinder.
  • ceph health is ok, all hardware are brand new
  • i don't see anything interesting in libvirt logs but you can read them here:

Maybe someone supposes what's going on or know how to debug this problem? I've stuck with this for almost a week :/ I would be grateful for any help.

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answered 2018-05-14 00:25:31 -0500

proacticalbob gravatar image

Check DNS /DHCP/ NTP and such like. I had a real pig where the MTU size is 1492-1500 , but when you add in the VM NW wrapping, it makes the MTU too large for the frame size, then it hangs whilst it recalculates.

Just a test set the VM MTU to 1400 to rule it out.

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You were right, problem was caused by too low MTU on ceph MON.

Thanks for help!

Damian Dąbrowski gravatar imageDamian Dąbrowski ( 2018-05-16 05:43:13 -0500 )edit

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Asked: 2018-05-11 10:24:51 -0500

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Last updated: May 14 '18