diff options
Diffstat (limited to 'Documentation/filesystems/nfs/nfsroot.txt')
| -rw-r--r-- | Documentation/filesystems/nfs/nfsroot.txt | 70 |
1 files changed, 60 insertions, 10 deletions
diff --git a/Documentation/filesystems/nfs/nfsroot.txt b/Documentation/filesystems/nfs/nfsroot.txt index 5efae00f6c7f..d2963123eb1c 100644 --- a/Documentation/filesystems/nfs/nfsroot.txt +++ b/Documentation/filesystems/nfs/nfsroot.txt @@ -5,6 +5,7 @@ Written 1996 by Gero Kuhlmann <gero@gkminix.han.de> Updated 1997 by Martin Mares <mj@atrey.karlin.mff.cuni.cz> Updated 2006 by Nico Schottelius <nico-kernel-nfsroot@schottelius.org> Updated 2006 by Horms <horms@verge.net.au> +Updated 2018 by Chris Novakovic <chris@chrisn.me.uk> @@ -79,7 +80,7 @@ nfsroot=[<server-ip>:]<root-dir>[,<nfs-options>] ip=<client-ip>:<server-ip>:<gw-ip>:<netmask>:<hostname>:<device>:<autoconf>: - <dns0-ip>:<dns1-ip> + <dns0-ip>:<dns1-ip>:<ntp0-ip> This parameter tells the kernel how to configure IP addresses of devices and also how to set up the IP routing table. It was originally called @@ -110,6 +111,9 @@ ip=<client-ip>:<server-ip>:<gw-ip>:<netmask>:<hostname>:<device>:<autoconf>: will not be triggered if it is missing and NFS root is not in operation. + Value is exported to /proc/net/pnp with the prefix "bootserver " + (see below). + Default: Determined using autoconfiguration. The address of the autoconfiguration server is used. @@ -123,10 +127,13 @@ ip=<client-ip>:<server-ip>:<gw-ip>:<netmask>:<hostname>:<device>:<autoconf>: Default: Determined using autoconfiguration. - <hostname> Name of the client. May be supplied by autoconfiguration, - but its absence will not trigger autoconfiguration. - If specified and DHCP is used, the user provided hostname will - be carried in the DHCP request to hopefully update DNS record. + <hostname> Name of the client. If a '.' character is present, anything + before the first '.' is used as the client's hostname, and anything + after it is used as its NIS domain name. May be supplied by + autoconfiguration, but its absence will not trigger autoconfiguration. + If specified and DHCP is used, the user-provided hostname (and NIS + domain name, if present) will be carried in the DHCP request; this + may cause a DNS record to be created or updated for the client. Default: Client IP address is used in ASCII notation. @@ -162,12 +169,55 @@ ip=<client-ip>:<server-ip>:<gw-ip>:<netmask>:<hostname>:<device>:<autoconf>: Default: any - <dns0-ip> IP address of first nameserver. - Value gets exported by /proc/net/pnp which is often linked - on embedded systems by /etc/resolv.conf. + <dns0-ip> IP address of primary nameserver. + Value is exported to /proc/net/pnp with the prefix "nameserver " + (see below). + + Default: None if not using autoconfiguration; determined + automatically if using autoconfiguration. + + <dns1-ip> IP address of secondary nameserver. + See <dns0-ip>. + + <ntp0-ip> IP address of a Network Time Protocol (NTP) server. + Value is exported to /proc/net/ipconfig/ntp_servers, but is + otherwise unused (see below). + + Default: None if not using autoconfiguration; determined + automatically if using autoconfiguration. + + After configuration (whether manual or automatic) is complete, two files + are created in the following format; lines are omitted if their respective + value is empty following configuration: + + - /proc/net/pnp: + + #PROTO: <DHCP|BOOTP|RARP|MANUAL> (depending on configuration method) + domain <dns-domain> (if autoconfigured, the DNS domain) + nameserver <dns0-ip> (primary name server IP) + nameserver <dns1-ip> (secondary name server IP) + nameserver <dns2-ip> (tertiary name server IP) + bootserver <server-ip> (NFS server IP) + + - /proc/net/ipconfig/ntp_servers: + + <ntp0-ip> (NTP server IP) + <ntp1-ip> (NTP server IP) + <ntp2-ip> (NTP server IP) + + <dns-domain> and <dns2-ip> (in /proc/net/pnp) and <ntp1-ip> and <ntp2-ip> + (in /proc/net/ipconfig/ntp_servers) are requested during autoconfiguration; + they cannot be specified as part of the "ip=" kernel command line parameter. + + Because the "domain" and "nameserver" options are recognised by DNS + resolvers, /etc/resolv.conf is often linked to /proc/net/pnp on systems + that use an NFS root filesystem. - <dns1-ip> IP address of second nameserver. - Same as above. + Note that the kernel will not synchronise the system time with any NTP + servers it discovers; this is the responsibility of a user space process + (e.g. an initrd/initramfs script that passes the IP addresses listed in + /proc/net/ipconfig/ntp_servers to an NTP client before mounting the real + root filesystem if it is on NFS). nfsrootdebug |