Troubleshooting

Improving NFS Performance on HPC Clusters with Dell Fluid Cache for DAS
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Example on the client:
[root@compute-0-0 ~]# mount –o vers=3 <ib0-IP-of-NFS-server>:/home/xfs
<mount-point-on-client>
A.6. Useful commands and references
DFC is installed in /opt/dell/fluidcache.
1. fldc is the command-line utility to configure DFC. Use fldc –h for the flags available.
2. To check status use fldc –-status.
3. Check for fldc events with fldc –-events. Use fldc –-num=<n> --events to see more than
last 10 events.
4. /opt/dell/fluidcache/bin/fldcstat is the utility to view and monitor DFC statistics. Check
the fldcstat manual pages for options and descriptions of the statistics that are available.
5. Dell OpenManage Server Administrator provides a GUI to configure, administer, and monitor the
server. Browse to https://localhost:1311
on the NFS server to see this GUI.
6. Enable IP ports on both the cluster servers. The list of ports to be enabled is in the Red Hat Storage
Administration Guide.
https://access.redhat.com/knowledge/docs/en-
US/Red_Hat_Enterprise_Linux/6/html/Storage_Administration_Guide/s2-nfs-nfs-firewall-
config.html
Alternately, turn off the firewall. Ensure that your public and private interfaces are on a secure
network and be aware of the security implications of turning off the firewall before implementing
this alternative:
[root@nfs-dfc ~]# service iptables stop; chkconfig iptables off
A.7. Performance tuning on clients
1. For each client, add the following to /etc/sysctl.conf to increase the TCP receive memory
buffer size
# increasing the default TCP receive memory size
net.ipv4.tcp_rmem = 4096 2621440 16777216
Activate the changes with sysctl -p.
2. Mount clients using NFS v3. A previous study
reported that NFSv3 has dramatically better metadata
create performance than NFS v4. This solution recommends NFS v3 except in cases where the
security enhancements in NFS v4 are critical.
[root@compute-0-0 ~]# mount –o vers=3 <ib0-IP-of-NFS-server>:/home/xfs
<mount-point-on-client>