[klibc] nfsmount default timeo=7 causes timeouts on 100 Mbps

Alkis Georgopoulos alkisg at gmail.com
Sat Sep 21 04:14:07 PDT 2019

I managed to get to the bottom of this, and filed a bug report for NFS:

Klibc nfsmount still a bug: it needs to NOT hardcode timeo=7.

Either the NFS defaults should be used,
which result in: timeo=600,rsize=1048576,wsize=1048576,
or at least the kernel documented defaults,
which are: timeo=7,rsize=4096,wsize=4096

But clearly hardcoding (the old) timeo=7 and leaving the (new) default 
rsize=1048576 is wrong and it's causing dmesg errors.

With all the workarounds applied, the traffic for netbooting a client 
with ext4-over-nfs dropped from e.g. 1160 MB to 221 MB, i.e. it's a 
major improvement.

More information about the klibc mailing list