/var/log/libvirt/libvirtd.log内容如下：
====== start of log =====
2019-05-14 01:06:03.593+000020276: debug : main:1024 : Decided on pid file path '/var/run/libvirtd.pid'
2019-05-14 01:06:03.593+000020276: debug : main:1034 : Decided on socket paths '/var/run/libvirt/libvirt-sock' and '/var/run/libvirt/libvirt-sock-ro'
2019-05-14 01:06:03.593+000020277: debug : virFileClose:72 : Closed fd 5
2019-05-14 01:06:03.593+000020277: debug : virFileClose:72 : Closed fd 5
2019-05-14 01:06:03.593+000020277: debug : virFileClose:72 : Closed fd 7
2019-05-14 01:06:03.593+000020278: debug : main:1071 : Ensuring run dir '/var/run/libvirt' exists
2019-05-14 01:06:03.593+000020278: debug : virNetlinkStartup:138 : Running global netlink initialization
2019-05-14 01:06:03.593+000020278: debug : virObjectNew:110 : OBJECT_NEW: obj=0x7fbc290affd0 classname=virNetServer
2019-05-14 01:06:03.594+000020278: debug : virEventRegisterDefaultImpl:204 : registering default event implementation
2019-05-14 01:06:03.594+000020278: debug : virEventPollAddHandle:111 : Used 0 handle slots, adding at least 10 more
2019-05-14 01:06:03.594+000020278: debug : virEventPollInterruptLocked:697 : Skip interrupt, 0 0
2019-05-14 01:06:03.594+000020278: debug : virEventPollAddHandle:136 : EVENT_POLL_ADD_HANDLE: watch=1 fd=7 events=1 cb=0x7fbc26776ac0 opaque=(nil) ff=(nil)
2019-05-14 01:06:03.594+000020278: debug : virEventRegisterImpl:177 : addHandle=0x7fbc26777d50 updateHandle=0x7fbc26776d60 removeHandle=0x7fbc26776c10 addTimeout=0x7fbc26777b80 updateTimeout=0x7fbc26776e80 removeTimeout=0x7fbc26776b00
2019-05-14 01:06:03.594+000020278: debug : main:1110 : Dropping privileges (if required)
2019-05-14 01:06:03.594+000020278: debug : virRegisterNetworkDriver:561 : registering Network as network driver 3
2019-05-14 01:06:03.594+000020278: debug : virRegisterInterfaceDriver:591 : registering Interface as interface driver 3
2019-05-14 01:06:03.594+000020278: debug : virRegisterStorageDriver:621 : registering storage as storage driver 3
2019-05-14 01:06:03.594+000020278: debug : udevNodeRegister:1811 : Registering udev node device backend
2019-05-14 01:06:03.594+000020278: debug : virRegisterDeviceMonitor:651 : registering udevDeviceMonitor as device driver 3
2019-05-14 01:06:03.594+000020278: debug : virRegisterSecretDriver:681 : registering secret as secret driver 3
2019-05-14 01:06:03.594+000020278: debug : virRegisterNWFilterDriver:711 : registering nwfilter as network filter driver 3
2019-05-14 01:06:03.594+000020278: debug : virRegisterDriver:729 : driver=0x7fbc2730ab80 name=QEMU
2019-05-14 01:06:03.594+000020278: debug : virRegisterDriver:744 : registering QEMU as driver 3
2019-05-14 01:06:03.594+000020278: debug : virRegisterDriver:729 : driver=0x7fbc2730b720 name=LXC
2019-05-14 01:06:03.594+000020278: debug : virRegisterDriver:744 : registering LXC as driver 4
2019-05-14 01:06:03.594+000020278: debug : virObjectNew:110 : OBJECT_NEW: obj=0x7fbc290b9980 classname=virNetServerProgram
2019-05-14 01:06:03.594+000020278: debug : virNetServerProgramNew:81 : prog=0x7fbc290b9980
2019-05-14 01:06:03.594+000020278: debug : virObjectRef:168 : OBJECT_REF: obj=0x7fbc290b9980
2019-05-14 01:06:03.594+000020278: debug : virObjectNew:110 : OBJECT_NEW: obj=0x7fbc290b9950 classname=virNetServerProgram
2019-05-14 01:06:03.594+000020278: debug : virNetServerProgramNew:81 : prog=0x7fbc290b9950
2019-05-14 01:06:03.594+000020278: debug : virObjectRef:168 : OBJECT_REF: obj=0x7fbc290b9950
2019-05-14 01:06:03.594+000020278: debug : virEventPollInterruptLocked:697 : Skip interrupt, 0 0
2019-05-14 01:06:03.594+000020278: debug : virEventPollAddHandle:136 : EVENT_POLL_ADD_HANDLE: watch=2 fd=9 events=1 cb=0x7fbc2686d720 opaque=0x7fbc290affd0 ff=(nil)
2019-05-14 01:06:03.594+000020278: debug : main:1161 : Attempting to configure auditing subsystem
2019-05-14 01:06:03.594+000020278: debug : virHookCheck:128 : No hook script /etc/libvirt/hooks/daemon
2019-05-14 01:06:03.594+000020278: debug : virHookCheck:128 : No hook script /etc/libvirt/hooks/qemu
2019-05-14 01:06:03.594+000020278: debug : virHookCheck:128 : No hook script /etc/libvirt/hooks/lxc
2019-05-14 01:06:03.594+000020278: debug : virHookCheck:128 : No hook script /etc/libvirt/hooks/network
2019-05-14 01:06:03.594+000020278: debug : daemonSetupNetworking:455 : Registering unix socket /var/run/libvirt/libvirt-sock
2019-05-14 01:06:03.594+000020278: debug : virObjectNew:110 : OBJECT_NEW: obj=0x7fbc290ad210 classname=virNetServerService
2019-05-14 01:06:03.594+000020278: debug : virNetSocketNew:147 : localAddr=0x7fff46ed6000 remoteAddr=(nil) fd=12 errfd=-1 pid=0
2019-05-14 01:06:03.594+000020278: debug : virObjectNew:110 : OBJECT_NEW: obj=0x7fbc290b1370 classname=virNetSocket
2019-05-14 01:06:03.594+000020278: debug : virNetSocketNew:204 : RPC_SOCKET_NEW: sock=0x7fbc290b1370 fd=12 errfd=-1 pid=0 localAddr=127.0.0.1;0, remoteAddr=(null)
2019-05-14 01:06:03.594+000020278: debug : virObjectRef:168 : OBJECT_REF: obj=0x7fbc290ad210
2019-05-14 01:06:03.594+000020278: debug : virObjectRef:168 : OBJECT_REF: obj=0x7fbc290b1370
2019-05-14 01:06:03.594+000020278: debug : virEventPollInterruptLocked:697 : Skip interrupt, 0 0
2019-05-14 01:06:03.594+000020278: debug : virEventPollAddHandle:136 : EVENT_POLL_ADD_HANDLE: watch=3 fd=12 events=0 cb=0x7fbc26876fb0 opaque=0x7fbc290b1370 ff=0x7fbc268773a0
2019-05-14 01:06:03.594+000020278: debug : daemonSetupNetworking:465 : Registering unix socket /var/run/libvirt/libvirt-sock-ro
2019-05-14 01:06:03.594+000020278: debug : virObjectNew:110 : OBJECT_NEW: obj=0x7fbc290ad350 classname=virNetServerService
2019-05-14 01:06:03.594+000020278: debug : virNetSocketNew:147 : localAddr=0x7fff46ed6000 remoteAddr=(nil) fd=13 errfd=-1 pid=0
2019-05-14 01:06:03.594+000020278: debug : virObjectNew:110 : OBJECT_NEW: obj=0x7fbc290ac180 classname=virNetSocket
2019-05-14 01:06:03.594+000020278: debug : virNetSocketNew:204 : RPC_SOCKET_NEW: sock=0x7fbc290ac180 fd=13 errfd=-1 pid=0 localAddr=127.0.0.1;0, remoteAddr=(null)
2019-05-14 01:06:03.594+000020278: debug : virObjectRef:168 : OBJECT_REF: obj=0x7fbc290ad350
2019-05-14 01:06:03.594+000020278: debug : virObjectRef:168 : OBJECT_REF: obj=0x7fbc290ac180
2019-05-14 01:06:03.594+000020278: debug : virEventPollInterruptLocked:697 : Skip interrupt, 0 0
2019-05-14 01:06:03.594+000020278: debug : virEventPollAddHandle:136 : EVENT_POLL_ADD_HANDLE: watch=4 fd=13 events=0 cb=0x7fbc26876fb0 opaque=0x7fbc290ac180 ff=0x7fbc268773a0
2019-05-14 01:06:03.594+000020278: debug : virObjectRef:168 : OBJECT_REF: obj=0x7fbc290ad210
2019-05-14 01:06:03.594+000020278: debug : virObjectRef:168 : OBJECT_REF: obj=0x7fbc290ad350
2019-05-14 01:06:03.597+000020278: debug : virObjectNew:110 : OBJECT_NEW: obj=0x7fbc290b4560 classname=virNetSASLContext
2019-05-14 01:06:03.597+000020278: debug : virFileClose:72 : Closed fd 6
2019-05-14 01:06:03.597+000020278: debug : virObjectRef:168 : OBJECT_REF: obj=0x7fbc290affd0
2019-05-14 01:06:03.597+000020278: info : virNetlinkEventServiceStart:558 : starting netlink event service with protocol 0
2019-05-14 01:06:03.597+000020278: debug : virEventPollInterruptLocked:697 : Skip interrupt, 0 0
2019-05-14 01:06:03.597+000020278: debug : virEventPollAddHandle:136 : EVENT_POLL_ADD_HANDLE: watch=5 fd=6 events=1 cb=0x7fbc267a5620 opaque=0x7fbc290b8090 ff=(nil)
2019-05-14 01:06:03.597+000020278: debug : virNetlinkEventServiceStart:605 : netlink event listener on fd: 6 running
2019-05-14 01:06:03.597+000020278: info : virNetlinkEventServiceStart:558 : starting netlink event service with protocol 15
2019-05-14 01:06:03.597+000020278: debug : virEventPollInterruptLocked:697 : Skip interrupt, 0 0
2019-05-14 01:06:03.597+000020278: debug : virEventPollAddHandle:136 : EVENT_POLL_ADD_HANDLE: watch=6 fd=14 events=1 cb=0x7fbc267a5620 opaque=0x7fbc290b82f0 ff=(nil)
2019-05-14 01:06:03.597+000020278: debug : virNetlinkEventServiceStart:605 : netlink event listener on fd: 14 running
2019-05-14 01:06:03.597+000020278: debug : virNetServerRun:724 : srv=0x7fbc290affd0 quit=0
2019-05-14 01:06:03.597+000020278: debug : virEventRunDefaultImpl:244 : running default event implementation
2019-05-14 01:06:03.597+000020278: debug : virEventPollCleanupTimeouts:501 : Cleanup 0
2019-05-14 01:06:03.597+000020278: debug : virEventPollCleanupTimeouts:537 : Found 0 out of 0 timeout slots used, releasing 0
2019-05-14 01:06:03.597+000020278: debug : virEventPollCleanupHandles:549 : Cleanup 6
2019-05-14 01:06:03.597+000020278: debug : virEventPollMakePollFDs:378 : Prepare n=0 w=1, f=7 e=1 d=0
2019-05-14 01:06:03.597+000020278: debug : virEventPollMakePollFDs:378 : Prepare n=1 w=2, f=9 e=1 d=0
2019-05-14 01:06:03.597+000020278: debug : virEventPollMakePollFDs:378 : Prepare n=2 w=3, f=12 e=0 d=0
2019-05-14 01:06:03.597+000020278: debug : virEventPollMakePollFDs:378 : Prepare n=3 w=4, f=13 e=0 d=0
2019-05-14 01:06:03.597+000020278: debug : virEventPollMakePollFDs:378 : Prepare n=4 w=5, f=6 e=1 d=0
2019-05-14 01:06:03.597+000020278: debug : virEventPollMakePollFDs:378 : Prepare n=5 w=6, f=14 e=1 d=0
2019-05-14 01:06:03.597+000020278: debug : virEventPollCalculateTimeout:320 : Calculate expiry of 0 timers
2019-05-14 01:06:03.597+000020278: debug : virEventPollCalculateTimeout:346 : Timeout at 0 due in -1 ms
2019-05-14 01:06:03.597+000020278: debug : virEventPollRunOnce:614 : EVENT_POLL_RUN: nhandles=4 timeout=-1
2019-05-14 01:06:03.597+000020289: debug : virStateInitialize:795 : Running global init for Remote state driver
2019-05-14 01:06:03.597+000020289: debug : virStateInitialize:795 : Running global init for Network state driver
2019-05-14 01:06:03.597+000020289: debug : virObjectNew:110 : OBJECT_NEW: obj=0x7fbc0c000930 classname=dnsmasqCaps
2019-05-14 01:06:03.598+000020289: debug : virCommandRunAsync:2229 : About to run LC_ALL=C PATH=/sbin:/usr/sbin:/bin:/usr/bin /usr/sbin/dnsmasq --version
2019-05-14 01:06:03.598+000020289: debug : virFileClose:72 : Closed fd 16
2019-05-14 01:06:03.598+000020289: debug : virFileClose:72 : Closed fd 18
2019-05-14 01:06:03.598+000020289: debug : virFileClose:72 : Closed fd 20
2019-05-14 01:06:03.598+000020289: debug : virCommandRunAsync:2250 : Command result 0, with PID 20290
2019-05-14 01:06:03.600+000020289: debug : virCommandRun:2045 : Result status 0, stdout: 'Dnsmasq version 2.48 Copyright (C) 2000-2009 Simon Kelley
Compile time options IPv6 GNU-getopt DBus no-I18N DHCP TFTP "--bind-interfaces with SO_BINDTODEVICE"
This software comes with ABSOLUTELY NO WARRANTY.
Dnsmasq is free software, and you are welcome to redistribute it
under the terms of the GNU General Public License, version 2 or 3.
' stderr: ''
2019-05-14 01:06:03.600+000020289: debug : virFileClose:72 : Closed fd 19
2019-05-14 01:06:03.600+000020289: debug : virFileClose:72 : Closed fd 17
2019-05-14 01:06:03.600+000020289: debug : virCommandRunAsync:2229 : About to run LC_ALL=C PATH=/sbin:/usr/sbin:/bin:/usr/bin /usr/sbin/dnsmasq --help
2019-05-14 01:06:03.600+000020289: debug : virFileClose:72 : Closed fd 16
2019-05-14 01:06:03.600+000020289: debug : virFileClose:72 : Closed fd 18
2019-05-14 01:06:03.600+000020289: debug : virFileClose:72 : Closed fd 20
2019-05-14 01:06:03.600+000020289: debug : virCommandRunAsync:2250 : Command result 0, with PID 20292
2019-05-14 01:06:03.602+000020289: debug : virCommandRun:2045 : Result status 0, stdout: 'Usage: dnsmasq [options]
Valid options are:
-a, --listen-address=ipaddr Specify local address(es) to listen on.
-A, --address=/domain/ipaddr Return ipaddr for all hosts in specified domains.
-b, --bogus-priv Fake reverse lookups for RFC1918 private address ranges.
-B, --bogus-nxdomain=ipaddr Treat ipaddr as NXDOMAIN (defeats Verisign wildcard).
-c, --cache-size=cachesize Specify the size of the cache in entries (defaults to 150).
-C, --conf-file=path Specify configuration file (defaults to /etc/dnsmasq.conf).
-d, --no-daemon Do NOT fork into the background: run in debug mode.
-D, --domain-needed Do NOT forward queries with no domain part.
-e, --selfmx Return self-pointing MX records for local hosts.
-E, --expand-hosts Expand simple names in /etc/hosts with domain-suffix.
-f, --filterwin2k Don't forward spurious DNS requests from Windows hosts.
-F, --dhcp-range=ipaddr,ipaddr,time Enable DHCP in the range given with lease duration.
-g, --group=groupname Change to this group after startup (defaults to dip).
-G, --dhcp-host=<hostspec> Set address or hostname for a specified machine.
--dhcp-hostsfile=<filename> Read DHCP host specs from file
--dhcp-optsfile=<filename> Read DHCP option specs from file
-h, --no-hosts Do NOT load /etc/hosts file.
-H, --addn-hosts=path Specify a hosts file to be read in addition to /etc/hosts.
-i, --interface=interface Specify interface(s) to listen on.
-I, --except-interface=int Specify interface(s) NOT to listen on.
-j, --dhcp-userclass=<tag>,<class> Map DHCP user class to tag.
--dhcp-circuitid=<tag>,<circuit>Map RFC3046 circuit-id to tag.
--dhcp-remoteid=<tag>,<remote> Map RFC3046 remote-id to tag.
--dhcp-subscrid=<tag>,<remote> Map RFC3993 subscriber-id to tag.
-J, --dhcp-ignore==<id>[,<id>] Don't do DHCP for hosts with tag set.
--dhcp-broadcast==<id>[,<id>] Force broadcast replies for hosts with tag set.
-k, --keep-in-foreground Do NOT fork into the background, do NOT run in debug mode.
-K, --dhcp-authoritative Assume we are the only DHCP server on the local network.
-l, --dhcp-leasefile=path Specify where to store DHCP leases (defaults to /var/lib/dnsmasq/dnsmasq.leases).
-L, --localmx Return MX records for local hosts.
-m, --mx-host=host_name,target,pref Specify an MX record.
-M, --dhcp-boot=<bootp opts> Specify BOOTP options to DHCP server.
-n, --no-poll Do NOT poll /etc/resolv.conf file, reload only on SIGHUP.
-N, --no-negcache Do NOT cache failed search results.
-o, --strict-order Use nameservers strictly in the order given in /etc/resolv.conf.
-O, --dhcp-option=<optspec> Specify options to be sent to DHCP clients.
--dhcp-option-force=<optspec> DHCP option sent even if the client does not request it.
-p, --port=number Specify port to listen for DNS requests on (defaults to 53).
-P, --edns-packet-max=<size> Maximum supported UDP packet size for EDNS.0 (defaults to 1280).
-q, --log-queries Log DNS queries.
-Q, --query-port=number Force the originating port for upstream DNS queries.
-R, --no-resolv Do NOT read resolv.conf.
-r, --resolv-file=path Specify path to resolv.conf (defaults to /etc/resolv.conf).
-S, --server=/domain/ipaddr Specify address(es) of upstream servers with optional domains.
--local=/domain/ Never forward queries to specified domains.
-s, --domain=<domain>[,<range>] Specify the domain to be assigned in DHCP leases.
-t, --mx-target=host_name Specify default target in an MX record.
-T, --local-ttl=time Specify time-to-live in seconds for replies from /etc/hosts.
--neg-ttl=time Specify time-to-live in seconds for negative caching.
-u, --user=username Change to this user after startup. (defaults to nobody).
-U, --dhcp-vendorclass=<id>,<class> Map DHCP vendor class to tag.
-v, --version Display dnsmasq version and copyright information.
-V, --alias=addr,addr,mask Translate IPv4 addresses from upstream servers.
-W, --srv-host=name,target,... Specify a SRV record.
-w, --help Display this message. Use --help dhcp for known DHCP options.
-x, --pid-file=path Specify path of PID file (defaults to /var/run/dnsmasq.pid).
-X, --dhcp-lease-max=number Specify maximum number of DHCP leases (defaults to 150).
-y, --localise-queries Answer DNS queries based on the interface a query was sent to.
-Y, --txt-record=name,txt.... Specify TXT DNS record.
--ptr-record=name,target Specify PTR DNS record.
--interface-name=name,interface Give DNS name to IPv4 address of interface.
-z, --bind-interfaces Bind only to interfaces in use.
-Z, --read-ethers Read DHCP static host information from /etc/ethers.
-1, --enable-dbus Enable the DBus interface for setting upstream servers, etc.
-2, --no-dhcp-interface=interface Do not provide DHCP on this interface, only provide DNS.
-3, --bootp-dynamic[=<id>[,<id>]] Enable dynamic address allocation for bootp.
-4, --dhcp-mac=<id>,<mac address> Map MAC address (with wildcards) to option set.
--bridge-interface=iface,alias,.Treat DHCP requests on aliases as arriving from interface.
-5, --no-ping Disable ICMP echo address checking in the DHCP server.
-6, --dhcp-script=path Script to run on DHCP lease creation and destruction.
-7, --conf-dir=path Read configuration from all the files in this directory.
-8, --log-facility=<facilty>|<file> Log to this syslog facility or file. (defaults to DAEMON)
-9, --leasefile-ro Do not use leasefile.
-0, --dns-forward-max=<queries> Maximum number of concurrent DNS queries. (defaults to 150)
--clear-on-reload Clear DNS cache when reloading /etc/resolv.conf.
--dhcp-ignore-names[=<id>[,<id>]Ignore hostnames provided by DHCP clients.
--dhcp-no-override Do NOT reuse filename and server fields for extra DHCP options.
--enable-tftp Enable integrated read-only TFTP server.
--tftp-root=<directory> Export files by TFTP only from the specified subtree.
--tftp-unique-root Add client IP address to tftp-root.
--tftp-secure Allow access only to files owned by the user running dnsmasq.
--tftp-max=<connections> Maximum number of conncurrent TFTP transfers (defaults to 50).
--tftp-no-blocksize Disable the TFTP blocksize extension.
--tftp-port-range=<start>,<end> Ephemeral port range for use by TFTP transfers.
--log-dhcp Extra logging for DHCP.
--log-async[=<log lines>] Enable async. logging; optionally set queue length.
--stop-dns-rebind Stop DNS rebinding. Filter private IP ranges when resolving.
--all-servers Always perform DNS queries to all servers.
--dhcp-match=<netid>,<optspec> Set tag if client includes matching option in request.
--dhcp-alternate-port[=<ports>] Use alternative ports for DHCP.
--dhcp-scriptuser=<username> Run lease-change script as this user.
--naptr-record=<name>,<naptr> Specify NAPTR DNS record.
--min-port=<port> Specify lowest port available for DNS query transmission.
--dhcp-fqdn Use only fully qualified domain names for DHCP clients.
--cname=<alias>,<target> Specify alias name for LOCAL DNS name.
--pxe-prompt=<prompt>,[<timeout>Prompt to send to PXE clients.
--pxe-service=<service> Boot service for PXE menu.
--test Check configuration syntax.
' stderr: ''
2019-05-14 01:06:03.602+000020289: debug : virFileClose:72 : Closed fd 19
2019-05-14 01:06:03.602+000020289: info : dnsmasqCapsSetFromBuffer:667 : dnsmasq version is 2.48, --bind-dynamic is NOT present, SO_BINDTODEVICE is NOT in use
2019-05-14 01:06:03.602+000020289: debug : virFileClose:72 : Closed fd 17
====== end of log =====tty终端报错如下：
[root@caiji-server1 libvirt]# service libvirtd status
libvirtd dead but pid file exists如何处理呢？
经过多次排错，可能相关依赖版本太低了
yum -y upgrade升级后，故障解除。