NFS Services Administrator Guide (5900-3045, March 2013)

To fix the krb5.conf file for proper domain name to realm matching, modify the file based
on the following sample:
#
# Kerberos configuration
# This krb5.conf file is intended as an example only.
# see krb5.conf(4) for more details
# hostname is the fully qualified hostname(FQDN) of host on
which kdc is running
# domain_name is the fully qualified name of your domain
[libdefaults]
default_realm = krbhost.anyrealm.com
default_tkt_enctypes = DES-CBC-CRC
default_tgs_enctypes = DES-CBC-CRC
ccache_type = 2
[realms]
krbhost.anyrealm.com = {
kdc = krbhost.anyrealm.com:88
admin_server = krbhost.anyrealm.com
}
[domain_realm]
.anyrealm.com = krbhost.anyrealm.com
[logging]
kdc = FILE:/var/log/krb5kdc.log
admin_server = FILE:/var/log/kadmin.log
default = FILE:/var/log/krb5lib.log
• The user who is trying to access the mounted filesystem has not obtained a TGT using their
login.
For example, if you are a guest user and are attempting to access the NFS mounted filesystem
with Kerberos security option, you need to have a TGT.
To identify the default principal name, enter the following command:
klist
If the default principal name is not ‘guest’, enter the following command to obtain a TGT for
the guest principal:
kinit guest
Performance Tuning
This section gives suggestions for identifying performance problems in your network and improving
NFS performance on your servers and clients. This section addresses the following topics:
• “Diagnose NFS Performance Problems” (page 100)
• “Improve NFS Server Performance” (page 101)
• “Improving NFS Client Performance” (page 101)
Diagnose NFS Performance Problems
1. Enter the following command on several of your NFS clients:
nfsstat -rc
2. If the timeout and retrans values displayed by nfsstat -rc are high, but the badxid
value is close to zero, packets are being dropped before they get to the NFS server.
Try decreasing the values of the wsize and rsize mount options to 4096 or 2048 on the
NFS clients. See “Changing the Default Mount Options” (page 38)“Changing the Default
Mount Options” on page 51 .
100 Troubleshooting NFS Services