Re: [libvirt] udevadm settle can take too long

Hi, On Sun, Apr 22, 2012 at 02:41:54PM -0400, Jim Paris wrote: > Hi, > > http://bugs.debian.org/663931 is a bug I'm hitting, where virt-manager > times out on the initial connection to libvirt. I reassigned the bug back to libvirt. I still wonder what triggers this though for some users but not for others? Cheers, -- Guido > > The basic problem is that, while checking storage volumes, > virt-manager causes libvirt to call "udevadm settle". There's an > interaction where libvirt's earlier use of network namespaces (to probe > LXC features) had caused some uevents to be sent that get filtered out > before they reach udev. This confuses "udevadm settle" a bit, and so > it sits there waiting for a 2-3 minute built-in timeout before returning. > Eventually libvirtd prints: > 2012-04-22 18:22:18.678+0000: 30503: warning : virKeepAliveTimer:182 : No response from client 0x7feec4003630 after 5 keepalive messages in 30 seconds > and virt-manager prints: > 2012-04-22 18:22:18.931+0000: 30647: warning : virKeepAliveSend:128 : Failed to send keepalive response to client 0x25004e0 > and the connection gets dropped. > > One workaround could be to specify a shorter timeout when doing the > settle. The patch appended below allows virt-manager to work, > although the connection still has to wait for the 10 second timeout > before it succeeds. I don't know what a better solution would be, > though. It seems the udevadm behavior might not be considered a bug > from the udev/kernel point of view: > https://lkml.org/lkml/2012/4/22/60 > > I'm using Linux 3.2.14 with libvirt 0.9.11. You can trigger the > udevadm issue using a program I posted at the Debian bug report link > above. > > -jim > > > From 17e5b9ebab76acb0d711e8bc308023372fbc4180 Mon Sep 17 00:00:00 2001 > From: Jim Paris<jim(a)jtan.com> > Date: Sun, 22 Apr 2012 14:35:47 -0400 > Subject: [PATCH] shorten udevadmin settle timeout > > Otherwise, udevadmin settle can take so long that connections from > e.g. virt-manager will get closed. > --- > src/util/util.c | 4 ++-- > 1 files changed, 2 insertions(+), 2 deletions(-) > > diff --git a/src/util/util.c b/src/util/util.c > index 6e041d6..dfe458e 100644 > --- a/src/util/util.c > +++ b/src/util/util.c > @@ -2593,9 +2593,9 @@ virFileFindMountPoint(const char *type ATTRIBUTE_UNUSED) > void virFileWaitForDevices(void) > { > # ifdef UDEVADM > - const char *const settleprog[] = { UDEVADM, "settle", NULL }; > + const char *const settleprog[] = { UDEVADM, "settle", "--timeout", "10", NULL };