[libvirt] [PATCH 1/2] Increase default file handle limits for virtlogd

[Christian Ehrhardt]

The initial assumption was ~2 files per guest, but some common setups
like Openstack drive up to 4 files per guest.

E.g. on Arm where the following XML leads to 4 file handles:
    <serial type='file'>
      <source path='/var/lib/nova/instances/7c0dcd78-.../console.log'/>
      <target port='0'/>
      <alias name='serial0'/>
    </serial>
    <console type='file'>
      <source path='/var/lib/nova/instances/7c0dcd78-.../console.log'/>
      <target type='serial' port='0'/>
      <alias name='serial0'/>
    </console>

With that in mind and the target to support 4k guests by default we
should raise the limit to 16k.

Signed-off-by: Christian Ehrhardt <christian.ehrhardt at canonical.com>
---
 src/logging/virtlogd.service.in | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/src/logging/virtlogd.service.in b/src/logging/virtlogd.service.in
index ec7712b..aa9aa69 100644
--- a/src/logging/virtlogd.service.in
+++ b/src/logging/virtlogd.service.in
@@ -15,9 +15,11 @@ ExecReload=/bin/kill -USR1 $MAINPID
 OOMScoreAdjust=-900
 # Need to have at least one file open per guest (eg QEMU
 # stdio log), but might be more (eg serial console logs)
+# A common case is OpenStack which often has up to 4 file
+# handles per guest.
 # libvirtd.service written to expect 4096 guests, so if we
-# guess at 2 log files per guest here (stdio + 1 serial):
-LimitNOFILE=8192
+# guess at 4 files per guest here that is 16k:
+LimitNOFILE=16384
 
 [Install]
 Also=virtlogd.socket
-- 
2.7.4