neels has uploaded this change for review. ( https://gerrit.osmocom.org/c/osmo-bsc/+/35173?usp=email )

Change subject: systemd,manual: set LimitNOFILE=65536 ......................................................................

systemd,manual: set LimitNOFILE=65536

A typical OS imposed limit is 1024 open FD, which is too low when there are hundreds of BTS.

In systemd service file, set a super high limit of 65536.

In osmo-bsc's user manual, add section 'Configure limits' describing this in detail.

Related: OS#6256 Change-Id: I26c4058484b11ff1d035a919bf88824c3af14e71 --- M contrib/systemd/osmo-bsc.service M doc/manuals/chapters/running.adoc 2 files changed, 37 insertions(+), 0 deletions(-)

git pull ssh://gerrit.osmocom.org:29418/osmo-bsc refs/changes/73/35173/1

diff --git a/contrib/systemd/osmo-bsc.service b/contrib/systemd/osmo-bsc.service index a345c47..c8dc877 100644 --- a/contrib/systemd/osmo-bsc.service +++ b/contrib/systemd/osmo-bsc.service @@ -7,6 +7,7 @@ [Service] Type=simple Restart=always +LimitNOFILE=65536 StateDirectory=osmocom WorkingDirectory=%S/osmocom ExecStart=/usr/bin/osmo-bsc -c /etc/osmocom/osmo-bsc.cfg -s diff --git a/doc/manuals/chapters/running.adoc b/doc/manuals/chapters/running.adoc index 9ff546c..66d4990 100644 --- a/doc/manuals/chapters/running.adoc +++ b/doc/manuals/chapters/running.adoc @@ -69,6 +69,24 @@ has to configure a distinct point-code. See <<cs7_config>>.

+=== Configure limits + +When connecting many multi-trx BTS to OsmoBSC, it may be necessary to adjust +the operating system's limit on file descriptors for the osmo-bsc process. A +typical default limit imposed by operating systems is 1024 open file +descriptors; this would be exceeded by, for example, about 205 BTS with 4 TRX +each. (Each BTS with 4 TRX requires 5 file descriptors for Abis; 205 * 5 +already exceeds 1024, other interfaces not even considered yet.) + +It should be ok to set an OS limit on open file descriptors as high as 65536 +for osmo-bsc, which practically rules out failure from running out of file +descriptors in setups with less than 50,000 TRX. + +When using systemd, the file descriptor limit may be adjusted in the service +file by the `LimitNOFILE` setting ("Number of Open FILE descriptors"). OsmoBSC +ships a systemd service file a high LimitNOFILE setting. + + === Configure primary links

==== Connect to an MSC's _A_ interface