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Bug 1035966 - Start autostarted virtual networks in background
Summary: Start autostarted virtual networks in background
Keywords:
Status: CLOSED ERRATA
Alias: None
Product: Red Hat Enterprise Linux 7
Classification: Red Hat
Component: libvirt
Version: 7.0
Hardware: x86_64
OS: Linux
low
low
Target Milestone: rc
: ---
Assignee: Laine Stump
QA Contact: Virtualization Bugs
URL:
Whiteboard:
Depends On:
Blocks:
TreeView+ depends on / blocked
 
Reported: 2013-11-29 03:37 UTC by Hu Jianwei
Modified: 2015-03-05 07:28 UTC (History)
7 users (show)

Fixed In Version: libvirt-1.2.7-1.el7
Doc Type: Bug Fix
Doc Text:
Restarting libvirtd with a large number of virtual networks configured was taking a very long time on systems with firewalld enabled, with libvirtd's services unavailable in the interim. This was due to libvirt repeatedly exec'ing firewall-cmd to add the relevant rules to the host's iptables chains, which was extremely slow. libvirt now manipulates firewalld via the dbus interface, which tests show to be 10x faster, resulting in greatly reduced downtime during libvirts restarts.
Clone Of:
Environment:
Last Closed: 2015-03-05 07:28:41 UTC
Target Upstream Version:
Embargoed:

Attachments (Terms of Use)
libvirtd.log and system messages log. (839.17 KB, application/x-gzip)
2013-12-02 08:49 UTC, Hu Jianwei 		no flags Details
View All


Links
System ID Private Priority Status Summary Last Updated
Red Hat Product Errata RHSA-2015:0323 0 normal SHIPPED_LIVE Low: libvirt security, bug fix, and enhancement update 2015-03-05 12:10:54 UTC

Description Hu Jianwei 2013-11-29 03:37:37 UTC 
Description of problem:
Existing a large number of autostarted virtual networks, libvirtd should rapidly respond to customer input after its daemon was restarted

Version-Release number of selected component (if applicable):
libvirt-1.1.1-12.el7.x86_64
qemu-kvm-1.5.3-19.el7.x86_64
kernel-3.10.0-48.el7.x86_64

How reproducible:
100%

Steps to Reproduce:
1. Enabled below limits.
[root@ibm-x3650m3-03 ~]# cat /etc/libvirt/libvirtd.conf | grep ^[^#]
max_clients = 204800
max_queued_clients = 1000000
max_workers = 204800
max_requests = 204800
max_client_requests = 204800
log_level = 1
log_outputs="1:file:/var/log/libvirt/libvirtd.log"
log_filters="1:qemu 1:libvirt 1:conf 1:json"

[root@ibm-x3850x5-01 ~]# cat /usr/lib/systemd/system/libvirtd.service| grep LimitNOFILE
LimitNOFILE=204800
[root@ibm-x3850x5-01 ~]#

2. Defined more than 256 autostarted virtual networks
[root@ibm-x3650m3-03 ~]#  virsh net-list | grep active | wc -l
256
[root@ibm-x3650m3-03 ~]#
[root@ibm-x3650m3-03 ~]# virsh net-list --all
 Name                 State      Autostart     Persistent
----------------------------------------------------------
 default              active     yes           yes
 network1             active     yes           yes
 network10            active     yes           yes
...

3. Restart libvirtd
[root@ibm-x3650m3-03 ~]# service libvirtd restart
Redirecting to /bin/systemctl restart  libvirtd.service

[root@ibm-x3650m3-03 ~]# service libvirtd status
Redirecting to /bin/systemctl status  libvirtd.service
libvirtd.service - Virtualization daemon
   Loaded: loaded (/usr/lib/systemd/system/libvirtd.service; enabled)
   Active: active (running) since Fri 2013-11-22 12:59:02 CST; 11min ago
 Main PID: 15579 (libvirtd)
   CGroup: /system.slice/libvirtd.service
           ├─ 2737 /sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/default.conf
           ├─15579 /usr/sbin/libvirtd
           ├─27413 /sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/network1.conf
           ├─27468 /sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/network2.conf
           ├─27523 /sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/network3.conf
           ├─27580 /sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/network4.conf
           ├─27635 /sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/network5.conf
           ├─27692 /sbin/dnsmasq --conf-file=/var/lib/libvirt/dnsmasq/network6.conf
...

4. Execute virsh cmd, and check the time consumption of cmd.
[root@ibm-x3650m3-03 ~]# time virsh list --all
 Id    Name                           State
----------------------------------------------------
 5     r7                             running
 -     r6                             shut off


real        19m5.009s
user        0m0.010s
sys        0m0.011s
[root@ibm-x3650m3-03 ~]#
[root@ibm-x3650m3-03 ~]# virsh net-list --all|grep active |wc -l
256

5. Running below commands during running step 4.
[root@ibm-x3650m3-03 ~]# ltrace -p `pidof libvirtd`
--- SIGCHLD (Child exited) ---
--- SIGCHLD (Child exited) ---
--- SIGCHLD (Child exited) ---
--- SIGCHLD (Child exited) ---
--- SIGCHLD (Child exited) ---
^C[root@ibm-x3650m3-03 ~]ltrace virsh list --all
__libc_start_main(0x7f6a068ad2b0, 3, 0x7fff2225c118, 0x7f6a068da1d0 <unfinished ...>
setlocale(LC_ALL, "")                                                                              = "LC_CTYPE=en_US.utf8;LC_NUMERIC=e"...
bindtextdomain("libvirt", "/usr/share/locale")                                                     = "/usr/share/locale"
textdomain("libvirt")                                                                              = "libvirt"
virMutexInit(0x7fff2225bfc0, 1, 1, 0x7472697662696c)                                               = 0
virInitialize(0x7fff2225bda0, 0x7f6a068da86a, 5, 0)                                                = 0
strrchr("virsh", '/')                                                                              = nil
virGetEnvBlockSUID(0x7f6a068da8a2, 9, 7, 5)                                                        = 0
virGetEnvAllowSUID(0x7f6a068da380, 9, 11, 34)                                                      = 0
virGetEnvBlockSUID(0x7f6a068da6f6, 9, 11, 0)                                                       = 0
getopt_long(3, 0x7fff2225c118, "+:d:hqtc:vVrl:e:", 0x7fff2225be20, -1)                             = -1
virStrdup(0x7fff2225bcc8, 0x7fff2225c69f, 1, 0)                                                    = 1
strcmp("attach-device", "list")                                                                    = -11
strcmp("attach-disk", "list")                                                                      = -11
strcmp("attach-interface", "list")                                                                 = -11
strcmp("autostart", "list")                                                                        = -11
strcmp("blkdeviotune", "list")                                                                     = -10
strcmp("blkiotune", "list")                                                                        = -10
strcmp("blockcommit", "list")                                                                      = -10
strcmp("blockcopy", "list")                                                                        = -10
strcmp("blockjob", "list")                                                                         = -10
strcmp("blockpull", "list")                                                                        = -10
strcmp("blockresize", "list")                                                                      = -10
strcmp("change-media", "list")                                                                     = -9
strcmp("console", "list")                                                                          = -9
strcmp("cpu-baseline", "list")                                                                     = -9
strcmp("cpu-compare", "list")                                                                      = -9
strcmp("cpu-stats", "list")                                                                        = -9
strcmp("create", "list")                                                                           = -9
strcmp("define", "list")                                                                           = -8
strcmp("desc", "list")                                                                             = -8
strcmp("destroy", "list")                                                                          = -8
strcmp("detach-device", "list")                                                                    = -8
strcmp("detach-disk", "list")                                                                      = -8
strcmp("detach-interface", "list")                                                                 = -8
strcmp("domdisplay", "list")                                                                       = -8
strcmp("domfstrim", "list")                                                                        = -8
strcmp("domhostname", "list")                                                                      = -8
strcmp("domid", "list")                                                                            = -8
strcmp("domif-setlink", "list")                                                                    = -8
strcmp("domiftune", "list")                                                                        = -8
strcmp("domjobabort", "list")                                                                      = -8
strcmp("domjobinfo", "list")                                                                       = -8
strcmp("domname", "list")                                                                          = -8
strcmp("dompmsuspend", "list")                                                                     = -8
strcmp("dompmwakeup", "list")                                                                      = -8
strcmp("domuuid", "list")                                                                          = -8
strcmp("domxml-from-native", "list")                                                               = -8
strcmp("domxml-to-native", "list")                                                                 = -8
strcmp("dump", "list")                                                                             = -8
strcmp("dumpxml", "list")                                                                          = -8
strcmp("edit", "list")                                                                             = -7
strcmp("inject-nmi", "list")                                                                       = -3
strcmp("send-key", "list")                                                                         = 7
strcmp("send-process-signal", "list")                                                              = 7
strcmp("lxc-enter-namespace", "list")                                                              = 15
strcmp("managedsave", "list")                                                                      = 1
strcmp("managedsave-remove", "list")                                                               = 1
strcmp("maxvcpus", "list")                                                                         = 1
strcmp("memtune", "list")                                                                          = 1
strcmp("migrate", "list")                                                                          = 1
strcmp("migrate-setmaxdowntime", "list")                                                           = 1
strcmp("migrate-compcache", "list")                                                                = 1
strcmp("migrate-setspeed", "list")                                                                 = 1
strcmp("migrate-getspeed", "list")                                                                 = 1
strcmp("numatune", "list")                                                                         = 2
strcmp("qemu-attach", "list")                                                                      = 5
strcmp("qemu-monitor-command", "list")                                                             = 5
strcmp("qemu-agent-command", "list")                                                               = 5
strcmp("reboot", "list")                                                                           = 6
strcmp("reset", "list")                                                                            = 6
strcmp("restore", "list")                                                                          = 6
strcmp("resume", "list")                                                                           = 6
strcmp("save", "list")                                                                             = 7
strcmp("save-image-define", "list")                                                                = 7
strcmp("save-image-dumpxml", "list")                                                               = 7
strcmp("save-image-edit", "list")                                                                  = 7
strcmp("schedinfo", "list")                                                                        = 7
strcmp("screenshot", "list")                                                                       = 7
strcmp("setmaxmem", "list")                                                                        = 7
strcmp("setmem", "list")                                                                           = 7
strcmp("setvcpus", "list")                                                                         = 7
strcmp("shutdown", "list")                                                                         = 7
strcmp("start", "list")                                                                            = 7
strcmp("suspend", "list")                                                                          = 7
strcmp("ttyconsole", "list")                                                                       = 8
strcmp("undefine", "list")                                                                         = 9
strcmp("update-device", "list")                                                                    = 9
strcmp("vcpucount", "list")                                                                        = 10
strcmp("vcpuinfo", "list")                                                                         = 10
strcmp("vcpupin", "list")                                                                          = 10
strcmp("emulatorpin", "list")                                                                      = -7
strcmp("vncdisplay", "list")                                                                       = 10
strcmp("domblkerror", "list")                                                                      = -8
strcmp("domblkinfo", "list")                                                                       = -8
strcmp("domblklist", "list")                                                                       = -8
strcmp("domblkstat", "list")                                                                       = -8
strcmp("domcontrol", "list")                                                                       = -8
strcmp("domif-getlink", "list")                                                                    = -8
strcmp("domiflist", "list")                                                                        = -8
strcmp("domifstat", "list")                                                                        = -8
strcmp("dominfo", "list")                                                                          = -8
strcmp("dommemstat", "list")                                                                       = -8
strcmp("domstate", "list")                                                                         = -8
strcmp("list", "list")                                                                             = 0
virFree(0x7fff2225bd80, 0x7fff2225bd78, 0x7fff2225bd7c, 0)                                         = 0x7f6a08090c90
virStrdup(0x7fff2225bcc8, 0x7fff2225c6a4, 1, 0)                                                    = 1
strchr("all", '=')                                                                                 = nil
strcmp("all", "help")                                                                              = -7
strcmp("inactive", "all")                                                                          = 8
strcmp("all", "all")                                                                               = 0
virFree(0x7fff2225bd80, 0, 3, 1)                                                                   = 0x7f6a08090c90
virAllocN(0x7fff2225bce8, 1, 24, 1)                                                                = 0
dcgettext(0x7f6a068da89a, 0x7f6a068da782, 5, 3)                                                    = 0x7f6a068da782
dcgettext(0x7f6a068da89a, 0x7f6a068da791, 5, 2)                                                    = 0x7f6a068da791
virFree(0x7fff2225bd80, 0x7fff2225be00, 0x7fff2225bd80, 0x7f6a068dbbe0)                            = 0
virAllocN(0x7fff2225bce8, 1, 24, 1)                                                                = 0
virGetEnvAllowSUID(0x7f6a068da380, 0x7f6a068dc4ae, 0x7f6a0801d420, 4)                              = 0
virGetEnvBlockSUID(0x7f6a068da6f6, 0x7f6a068dc4ae, 11, 0)                                          = 0
virSetErrorFunc(0, 0x7f6a068aecc0, 4, 0xffff8095f9725946)                                          = 0x7f6a0666a230
virEventRegisterDefaultImpl(0, 0x7f6a068aecc0, 4, 0xffff8095f9725946)                              = 0
virThreadCreate(0x7fff2225bfb8, 1, 0x7f6a068b0360, 0x7fff2225bf60)                                 = 0
virConnectOpenAuth(0, 0x7f6a066676e0, 0, -1^C <no return ...>
--- SIGINT (Interrupt) ---
+++ killed by SIGINT +++

Actual results:
Above example is 256 autostarted virtual networks, if you enlarge the number of network, user will wait a longer time to get response from libvirtd. 

If setting network autostart off, the response time will be reduced a lot, the time is acceptance.

1.Another example:(765 autostarted virtual networks)
[root@ibm-x3850x5-01 ~]# time virsh list --all
 Id    Name                           State
----------------------------------------------------


real        79m39.460s
user        0m0.015s
sys        0m0.022s
[root@ibm-x3850x5-01 ~]# virsh net-list --all | grep active | wc -l
765
[root@ibm-x3850x5-01 ~]#

2. Also, when we reduce the autostarted virtual network number to 51, the consumption was less than 3 minutes
[root@ibm-x3650m3-03 ~]# service libvirtd restart
Redirecting to /bin/systemctl restart  libvirtd.service
Warning: Unit file of libvirtd.service changed on disk, 'systemctl daemon-reload' recommended.
[root@ibm-x3650m3-03 ~]#
[root@ibm-x3650m3-03 ~]# time virsh list --all
 Id    Name                           State
----------------------------------------------------
 5     r7                             running
 -     r6                             shut off


real        2m53.779s
user        0m0.013s
sys        0m0.011s
[root@ibm-x3650m3-03 ~]# virsh net-list --all| grep active |wc -l
51

Expected results:
Libvirt should deal with this situation， give a quick reply to customer when handling a lot of events.
Comment 1 Hu Jianwei 2013-11-29 03:39:43 UTC 
More questions on this issue:

1. Virsh commands(such as "virsh list --all", "virsh net-list --all", etc) will be blocked by libvirtd while its daemon is starting a lot of virtual networks in background. When libvirtd handled all background events(here is virtual network), all virsh commands responded to customer quickly. I think libvirtd should deal with foreground input with higher priority at anytime. What do you think of my opinion?

2. Are there some risk conditions between user input and libvirt daemon or among libvitd's child threads?

Thanks.
Comment 2 Alex Jia 2013-11-29 08:19:41 UTC 
(In reply to Hu Jianwei from comment #1)
> 2. Are there some risk conditions between user input and libvirt daemon or

s/risk/race/, Jianwei, please attach relevant log files and make sure you haven't touch any limitation.
Comment 3 Hu Jianwei 2013-12-02 08:49:28 UTC 
Created attachment 831471 [details]
libvirtd.log and system messages log.

I can't find any useful log from attached logs, no error info recorded.
Comment 4 Jiri Denemark 2013-12-02 10:08:31 UTC 
This is basically a request to start virtual networks in background so that a starting libvirtd is not blocked until all networks are set up. While this is a nice idea, I'm not convinced it's worth implementing. Is there any real reason one would need to deploy lots of autostarted virtual networks on a single host?
Comment 5 Daniel Berrangé 2013-12-02 10:12:00 UTC 
Before we even look at doing clever things in autostarting networks, we should get clear data on what is slow about starting them serially. If we can make starting of individual networks faster then that is a better win overall than focusing on playing tricks at libvirtd startup.
Comment 6 Hu Jianwei 2013-12-03 01:48:13 UTC 
(In reply to Jiri Denemark from comment #4)
> This is basically a request to start virtual networks in background so that
> a starting libvirtd is not blocked until all networks are set up. While this
> is a nice idea, I'm not convinced it's worth implementing. Is there any real
> reason one would need to deploy lots of autostarted virtual networks on a
> single host?

No customer requirement for real deployment, only a testing scenario, but I think we could do some optimization to get better user experience, if possible.
Comment 8 Laine Stump 2014-04-28 09:28:21 UTC 
Dan Berrange has just pushed patches upstream that have a very significant effect on network start time when firewalld is enabled on the system - if the testing done above was on a system with firewalld enabled, it would be useful to try it again with a build of the latest upstream source to see if the situation is now acceptable.
Comment 9 Daniel Berrangé 2014-04-28 09:34:23 UTC 
Yes, speed of starting virtual networks when firewalld is running has improved dramatically

https://www.redhat.com/archives/libvir-list/2014-April/msg00335.html

"timing the network driver

 $ for i in `seq 1 10` ; do virsh net-start default; virsh net-destroy default ; done

   Direct iptables:  3 seconds
  Via firewall-cmd: 42 seconds"

So on a firewalld enabled host we cut time to start 10 networks from 42 seconds down to 3 seconds, so it is on a par with non-firewalld based hosts.
Comment 10 Jiri Denemark 2014-08-07 14:50:25 UTC 
As Daniel said, this should be dramatically improved by not using firewalld-cmd anymore.
Comment 11 Hu Jianwei 2014-08-08 06:14:42 UTC 
Compared with former results, libvirt has a great improvement.

For 249 virtual networks, virsh will take 2m4.517s
For 504 virtual networks, virsh will take 5m10.606s
For 759 virtual networks, virsh will take 8m45.235s

(On old libvirt:
256 vnet will spend 19m5.009s
765 vnet will spend 79m39.460s
)

Detail steps:
[root@localhost 1035966]# rpm -q libvirt kernel
libvirt-1.2.7-1.el7.x86_64
kernel-3.10.0-138.el7.x86_64

For 249 virtual networks
[root@localhost 1035966]# virsh net-list | grep active | wc -l
249
[root@localhost 1035966]# service libvirtd restart
Redirecting to /bin/systemctl restart  libvirtd.service

[root@localhost 1035966]# time virsh list --all
 Id    Name                           State
----------------------------------------------------
 20    r7_latest                      running
 -     r7                             shut off
 -     r7_1                           shut off
 -     r7_n                           shut off


real	2m4.517s
user	0m0.007s
sys	0m0.004s
[root@localhost 1035966]# time virsh list --all
 Id    Name                           State
----------------------------------------------------
 20    r7_latest                      running
 -     r7                             shut off
 -     r7_1                           shut off
 -     r7_n                           shut off


real	0m0.015s
user	0m0.007s
sys	0m0.003s

For 504 virtual networks
[root@localhost 1035966]# virsh net-list | grep active | wc -l
504
[root@localhost 1035966]#  time virsh list --all
 Id    Name                           State
----------------------------------------------------
 20    r7_latest                      running
 -     r7                             shut off
 -     r7_1                           shut off
 -     r7_n                           shut off


real	0m0.016s
user	0m0.005s
sys	0m0.005s
[root@localhost 1035966]# service libvirtd restart
Redirecting to /bin/systemctl restart  libvirtd.service
[root@localhost 1035966]#  time virsh list --all
 Id    Name                           State
----------------------------------------------------
 20    r7_latest                      running
 -     r7                             shut off
 -     r7_1                           shut off
 -     r7_n                           shut off


real	5m10.606s
user	0m0.006s
sys	0m0.006s
[root@localhost 1035966]#  time virsh list --all
 Id    Name                           State
----------------------------------------------------
 20    r7_latest                      running
 -     r7                             shut off
 -     r7_1                           shut off
 -     r7_n                           shut off


real	0m0.017s
user	0m0.007s
sys	0m0.005s

For 759 virtual networks
[root@localhost 1035966]#  time virsh list --all
 Id    Name                           State
----------------------------------------------------
 20    r7_latest                      running
 -     r7                             shut off
 -     r7_1                           shut off
 -     r7_n                           shut off


real	0m0.020s
user	0m0.005s
sys	0m0.007s
[root@localhost 1035966]# virsh net-list | grep active | wc -l
759
[root@localhost 1035966]# service libvirtd restart
Redirecting to /bin/systemctl restart  libvirtd.service
[root@localhost 1035966]#  time virsh list --all
 Id    Name                           State
----------------------------------------------------
 20    r7_latest                      running
 -     r7                             shut off
 -     r7_1                           shut off
 -     r7_n                           shut off


real	8m45.235s
user	0m0.005s
sys	0m0.006s
[root@localhost 1035966]#  time virsh list --all
 Id    Name                           State
----------------------------------------------------
 20    r7_latest                      running
 -     r7                             shut off
 -     r7_1                           shut off
 -     r7_n                           shut off


real	0m0.018s
user	0m0.004s
sys	0m0.008s
Comment 12 Hu Jianwei 2014-11-18 13:04:26 UTC 
According to comment 11, it's acceptable, changed to Verified.
Comment 13 Hu Jianwei 2015-01-15 09:00:54 UTC 
I found a machine, its libvirtd has a quicker reply than other machines I used before.

251 networks(real 0m21.877s)
510 networks(real 1m10.441s)
765 networks(real 2m25.811s)

Software environment:
[root@intel-e31225-8-3 network]# rpm -q libvirt kernel
libvirt-1.2.8-12.el7.x86_64
kernel-3.10.0-221.el7.x86_64

[root@intel-e31225-8-3 network]# lscpu 
Architecture:          x86_64
CPU op-mode(s):        32-bit, 64-bit
Byte Order:            Little Endian
CPU(s):                4
On-line CPU(s) list:   0-3
Thread(s) per core:    1
Core(s) per socket:    4
Socket(s):             1
NUMA node(s):          1
Vendor ID:             GenuineIntel
CPU family:            6
Model:                 42
Model name:            Intel(R) Xeon(R) CPU E31225 @ 3.10GHz
Stepping:              7
CPU MHz:               2928.410
BogoMIPS:              6184.19
Virtualization:        VT-x
L1d cache:             32K
L1i cache:             32K
L2 cache:              256K
L3 cache:              6144K
NUMA node0 CPU(s):     0-3
[root@intel-e31225-8-3 network]# free -g
              total        used        free      shared  buff/cache   available
Mem:              7           2           0           0           4           4
Swap:             7           0           7
[root@intel-e31225-8-3 network]# uptime 
 16:25:46 up  5:45,  2 users,  load average: 0.01, 0.06, 10.21
[root@intel-e31225-8-3 network]# service libvirtd restart
Redirecting to /bin/systemctl restart  libvirtd.service
[root@intel-e31225-8-3 network]# time virsh -q net-list |wc -l
765

real	2m20.285s
user	0m0.069s
sys	0m0.050s

Same software environment on another machine:
[root@hp-dl385g7-08 network]# rpm -q libvirt kernel
libvirt-1.2.8-12.el7.x86_64
kernel-3.10.0-221.el7.x86_64

[root@hp-dl385g7-08 network]# lscpu 
Architecture:          x86_64
CPU op-mode(s):        32-bit, 64-bit
Byte Order:            Little Endian
CPU(s):                32
On-line CPU(s) list:   0-31
Thread(s) per core:    2
Core(s) per socket:    8
Socket(s):             2
NUMA node(s):          4
Vendor ID:             AuthenticAMD
CPU family:            21
Model:                 1
Model name:            AMD Opteron(TM) Processor 6272
Stepping:              2
CPU MHz:               2100.010
BogoMIPS:              4199.77
Virtualization:        AMD-V
L1d cache:             16K
L1i cache:             64K
L2 cache:              2048K
L3 cache:              6144K
NUMA node0 CPU(s):     0,2,4,6,8,10,12,14
NUMA node1 CPU(s):     16,18,20,22,24,26,28,30
NUMA node2 CPU(s):     1,3,5,7,9,11,13,15
NUMA node3 CPU(s):     17,19,21,23,25,27,29,31
[root@hp-dl385g7-08 network]# free -g
              total        used        free      shared  buff/cache   available
Mem:             62           3          47           0          11          58
Swap:            31           0          31
[root@hp-dl385g7-08 network]# service libvirtd restart
Redirecting to /bin/systemctl restart  libvirtd.service
[root@hp-dl385g7-08 network]# time virsh net-list | wc -l
768

real	20m54.478s
user	0m0.178s
sys	0m0.308s
Comment 15 errata-xmlrpc 2015-03-05 07:28:41 UTC 
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHSA-2015-0323.html
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