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Options

Commonly used NFS options.

See man page for all options.

Tip

async increases write speed only - do not use for RO mounts as it will have no effect.

Option Purpose
all_squash[no_all_squash] Map all UID/GIDs to anonymous user; this is nobody for Debian.
anonuid Anonymous user ID.
anongid Anonymous group ID.
async Violate NFS protocol and reply before changes committed (unsafe).
sync Reply after changes are committed to disk (safe).
crossmnt Enable traversing of directories below exported root.
fsc Use filesystem cache. NFS will not use cache unless explicitly set.
fsid root or 0 has special meaning in which all other exports are mounted underneath it. Root should only be used if the filesystem does not have a UUID. Modern systems shouldn't use this.
mountpoint Only export if successfully mounted first (ZFS only).
no_subtree_check Disable checking if file is in exported subtree (slow) this is disabled by default.
nohide Do not hide sub-exports on same filesystems.
rw Read/write.
ro Readonly.
root_squash[no_root_squash] Map UID/GID 0 to anonymous user; this is nobody (65534) for debian.
sec=sys Use local UIDs/GIDs authentication.
sec=krb5 Kerberos authentication only.
sec=krb5i Kerberos authentication and secure checksums.
sec=krb5p Kerberos authentication, secure checksums, NFS traffic encryption.
nocto lose-to-open consistency - client trusts freshness of its view of the file and directory until cache attribute timers (actimo) elapses. Improves performance for read-only mounts only if ata changes occasionally. Reduces getattr access calls ~65-70%.
cto close-to-open consistency (default) - ensures that on open the most recent data for a file is always presented to the application.
actimo Sets acregmin, acregmax, acdirmin, acdirmax. actimo=600 additionally reduces getattr access calls ~20-25% with nocto.
noatime Disable inode access time update on read. Implies nodiratime.
nodiratime Disable directory inode access time update on read.

Reference:1234567

  1. https://man7.org/linux/man-pages/man5/nfs.5.html ↩

  2. https://www.thegeekdiary.com/common-nfs-mount-options-in-linux/ ↩

  3. https://learn.microsoft.com/en-us/azure/azure-netapp-files/performance-linux-mount-options ↩

  4. https://www.admin-magazine.com/HPC/Articles/Useful-NFS-Options-for-Tuning-and-Management ↩

  5. https://wiki.archlinux.org/title/NFS ↩

  6. https://docs.redhat.com/en/documentation/red_hat_enterprise_linux/4/html/reference_guide/s2-nfs-client-config-options#s2-nfs-client-config-options ↩

  7. https://unix.stackexchange.com/questions/427597/implications-of-using-nfsv4-fsid-0-and-exporting-the-nfs-root-to-entire-lan-or ↩