Performance implications of hard or soft NFS mounts

One of the choices you have when configuring NFS-mounted directories is whether you want hard (mount-o hard) or soft (mount-o soft) mounts.

After the filesystem is mounted, the soft mounts retry requests up to a value that is specified by the retrans option before the mount operation is failed. The default value of the retrans mount option is 5.

After the filesystem is mounted, the hard mounts retry requests indefinitely. The intr mount option is used by default, so the request can still be interrupted by a user signal unless the nointr mount option is specified. For description of all mount flags and options, see the mount command.

Although soft-mounting the directories causes the error to be detected by failing an operation rather than appearing to hang, the soft-mount operation runs a serious risk of data corruption. In general, read or write directories must be hard-mounted.