文章描述了在SUSELinuxEnterpriseServer15SP2和12SP5上，NFS客户端出现超时问题，表现为服务器无响应。该问题由内核中的lockless优化在pfifo_fast队列调度器中导致，已在上游报告并正在解决。SUSE提供了内核维护更新来禁用此优化。此外，还提供了一种无需更新内核的临时解决方案，即切换到fq_codel队列调度器。
Environment
SUSE Linux Enterprise Server 15 SP2
SUSE Linux Enterprise Server 12 SP5
Situation
This problem manifests itself in several ways; the one observed in the field was Linux NFS client timing out, with the following message logged in the system log:
nfs: server *HOSTNAME* not responding, still trying
and after several minutes
nfs: server *HOSTNAME* OK
Because of an in-kernel retransmit timer (or another packet being queued), the stuck packet will eventually be sent out, after a delay.
In tcpdump packet capture analysis, this problem can be identified by spurious resend attempts of the same packet (with equal TSVal) a long time apart.
Resolution
This problem has been reported upstream [3] and the proper fix is still in the works by the Linux Kernel community.
SUSE has released kernel maintanance update that will mitigate this probl
最低0.47元/天 解锁文章
扫一扫
1091
到【灌水乐园】发言
