Re: [libvirt] [PATCH 2/6] Save daemon logs to libvirtd.log
On Thu, Mar 03, 2011 at 06:22:13PM +0800, Daniel Veillard wrote:
Depending on whether it's run as root or user, the log is saved
in the local state dir or in $HOME/.libvirt. The file descriptor
is kept as a global variable used by following patches.
* daemon/libvirtd.c: add libvirtd.log as the output for logs
Signed-off-by: Daniel Veillard <veillard(a)redhat.com>
---
daemon/libvirtd.c | 90 ++++++++++++++++++++++++++++++++++++++++++++++++++---
1 files changed, 85 insertions(+), 5 deletions(-)
I don't think doing this is a good idea for a couple of reasons.
First, I find that many people have already altered the libvirtd.conf
file to log to /var/log/libvirtd.log by default instead of syslog.
Second, when you have the log priority set to debug as this patch
does, the logfile can get *VERY* large *VERY* quickly. eg, when
RHEV is using libvirt it is not uncommon to see a 300 MB of logs
generated in a mere 10 minutes, just from a fairly tightly targetted
filter like '1:qemu 1:util 1:libvirt'. If we write all logs unfiltered
at debug priority, then we will easily hit > 1 GB of data in < 10 mins.
This patch isn't allowing admins any way to turn off this extra
libvirtd.log in the cases where they are already collecting the data
via a different log output.
I agree with the idea of having a dedicated libvirtd.log file by
default though. So why don't we just change our default logging
configuration to use a logfile, instead of syslog. eg change this
block of code in libvirtd.c:
if (godaemon) {
if (virAsprintf(&tmp, "%d:syslog:libvirtd",
virLogGetDefaultPriority()) < 0)
goto no_memory;
} else {
if (virAsprintf(&tmp, "%d:stderr",
virLogGetDefaultPriority()) < 0)
goto no_memory;
}
To be
if (privileged) {
if (virAsprintf(&tmp, "%d:file:/var/log/libvirt/libvirtd.log",
virLogGetDefaultPriority()) < 0)
goto no_memory;
} else {
char *userdir = virGetUserDirectory(geteuid());
if (!userdir)
goto no_memory;
if (virAsprintf(&tmp, "%s/.libvirt/libvirtd.log", userdir) <
0) {
VIR_FRE(userdir);
goto no_memory;
}
VIR_FRE(userdir);
}
Thus people can just adjust 'log_debug' or 'log_filters' settings in
libvirtd.conf if they want more verbose logging.
Regards,
Daniel
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