nfs-utils

From Gentoo Wiki
Jump to:navigation Jump to:search
This page is a translated version of the page Nfs-utils and the translation is 36% complete.
Other languages:
Not to be confused with NTFS.
Resources
This article has some todo items:
  • Review systemd support in article. man nfs.systemd, /etc/nfs.conf, etc.
  • Add ss example above netstat

Network File System (NFS) は、ホストシステムが提供するネットワークアタッチドファイルシステム (エクスポートとも呼ばれます) にクライアントマシンがアクセスできるようにする、ファイルシステムプロトコルです。 NFS は Linux カーネルによってサポートされており、ユーザスペースデーモンとユーティリティは net-fs/nfs-utils パッケージにあります。

インストール

カーネル

NFS サーバサポートは NFS クライアントには不要です。逆も同様で、NFS クライアントサポートは NFS サーバには不要です。inotify サポートは NFSv4 でのみ必要です。NFSv3 はレガシークライアントとの互換性のためだけに必要です。例えば、BusyBox の mount コマンドは NFSv4 に対応していません。

クライアントサポート

クライアントカーネルサポートは、NFS エクスポートを実行するホストに接続する各システムで有効化する必要があります。

カーネル NFS クライアントサポートを有効化する
File systems --->
  [*] Inotify support for userspace
  [*] Network File Systems --->
        <*>   NFS client support
        <*>     NFS client support for NFS version 3
        <*>     NFS client support for NFS version 4
        [*]   NFS client support for NFSv4.1

サーバサポート

サーバカーネルサポートは、NFS エクスポートを提供するシステムでのみ必要です。ローカル上のテスト目的では、サーバ上でも前節で示したクライアントサポートも同様に有効化しておくと役に立つかもしれません。

カーネル NFS サーバサポートを有効化する
File systems --->
  [*] Inotify support for userspace
  [*] Network File Systems --->
        <*>   NFS server support
        [*]     NFS server support for NFS version 3
        [*]     NFS server support for NFS version 4
        [*]       NFSv4.1 server support for Parallel NFS (pNFS)

USE フラグ

USE flags for net-fs/nfs-utils NFS client and server daemons

caps Use Linux capabilities library to control privilege
junction Enable NFS junction support in nfsref
kerberos Add kerberos support
ldap Add ldap support
libmount Link mount.nfs with libmount
nfsdcld Enable nfsdcld NFSv4 clientid tracking daemon
nfsidmap Enable support for newer nfsidmap helper
nfsv4 Enable support for NFSv4
nfsv41 Enable support for NFSv4.1
sasl Add support for the Simple Authentication and Security Layer
selinux !!internal use only!! Security Enhanced Linux support, this must be set by the selinux profile or breakage will occur
tcpd Add support for TCP wrappers
uuid Support UUID lookups in rpc.mountd
Data provided by the Gentoo Package Database · Last update: 2022-12-26 08:32 More information about USE flags

Emerge

net-fs/nfs-utils をインストールしてください:

root #emerge --ask net-fs/nfs-utils

設定

サーバ

次の表に、サーバがエクスポートしようとしているファイルシステムを示します:

デバイス マウントディレクトリ 説明
/dev/sdb1 /home ユーザのホームディレクトリを格納するファイルシステム。
/dev/sdc1 /data ユーザのデータを格納するファイルシステム。

仮想ルート

エクスポートするファイルシステム群を、単一のディレクトリの下からアクセスできるようにすることがあります。このディレクトリは仮想ルートディレクトリとして知られています:

root #mkdir /export
注意
この記事では仮想ルートディレクトリとして /export ディレクトリを使用していますが、/nfs や /srv/nfs など、好きなディレクトリを使用することができます。

仮想ルートディレクトリ内に、エクスポートしたいファイルシステムのためのディレクトリ (例えば /home と /data) を作成してください:

root #mkdir /export/home
root #mkdir /export/data

エクスポートするファイルシステム群を、仮想ルートディレクトリ内の対応するディレクトリからアクセスできるようにする必要があります。これは mount コマンドの --bind オプションによって実現できます:

root #mount --bind /home /export/home
root #mount --bind /data /export/data

上のマウントを永続的なものにするには、/etc/fstab に以下を追記してください:

ファイル /etc/fstab
/home    /export/home    none    bind    0    0
/data    /export/data    none    bind    0    0

エクスポート

The filesystems to be made accessible for clients are specified in /etc/exports. This file consists of the directories to be exported, the clients allowed to access those directories, and a list options for each client. Refer to man exports for more information about the NFS export configuration options.

The following table briefly describes the server options used in the configuration below:

Option Description
insecure The server will require that client requests originate on unprivileged ports (those above 1024). This option is required when mounting exported directories from OS X or by the nfs:/ kioslave in KDE. The default is to use privileged ports.
rw The client will have read and write access to the exported directory. The default is to allow read-only access.
sync The server must wait until filesystem changes are committed to storage before responding to further client requests. This is the default.
no_subtree_check The server will not verify that a file requested by a client is in the appropriate filesystem and exported tree. This is the default.
crossmnt The server will reveal filesystems that are mounted under the virtual root directory that would otherwise be hidden when a client mounts the virtual root directory.
fsid=0 This option is required to uniquely identify the virtual root directory.

If changes are made to /etc/exports after the NFS server has started, issue the following command to propagate the changes to clients:

root #exportfs -rv
注意
Even though the contrary is written in a lot of places, it is also possible to directly export the required directory, without creating a virtual root:
ファイル /etc/exports
/home    192.0.2.0/24(insecure,rw,sync,no_subtree_check)
IPv4

Configuration grants access to the exported local shares, access is granted to the clients in the192.0.2.0/24 IP network. Client access can also be specified as a single host (IP address or fully qualified domain name), NIS netgroup, or with a single * character which grants all clients access.

ファイル /etc/exports
/export         192.0.2.0/24(insecure,rw,sync,no_subtree_check,crossmnt,fsid=0)
/export/home    192.0.2.0/24(insecure,rw,sync,no_subtree_check)
/export/data    192.0.2.0/24(insecure,rw,sync,no_subtree_check)
IPv6

IPv6 only configuration. Allowed IPv6 prefixes are put after the already configured IPv4 networks. The above configuration grants access to the exported directories by IP network, in this case 2001:db8:1::/64. These IP networks are allowed to access the exported shares on the NFS server:

ファイル /etc/exports
/export         2001:db8:1::/64(insecure,rw,sync,no_subtree_check,crossmnt,fsid=0)
/export/home    2001:db8:1::/64(insecure,rw,sync,no_subtree_check)
/export/data    2001:db8:1::/64(insecure,rw,sync,no_subtree_check)
Dual stack configuration

IPv4 and IPv6 networks which are allowed to access the exported shares on the NFS server, here 192.0.2.0/24 and 2001:db8:1::/64.

ファイル /etc/exports
/export         192.0.2.0/24(insecure,rw,sync,no_subtree_check,crossmnt,fsid=0) 2001:db8:1::/64(insecure,rw,sync,no_subtree_check,crossmnt,fsid=0)
/export/home    192.0.2.0/24(insecure,rw,sync,no_subtree_check) 2001:db8:1::/64(insecure,rw,sync,no_subtree_check)
/export/data    192.0.2.0/24(insecure,rw,sync,no_subtree_check) 2001:db8:1::/64(insecure,rw,sync,no_subtree_check)

デーモン

OpenRC

The NFS daemon on OpenRC is configured via the OPTS_RPC_NFSD variable:

ファイル /etc/conf.d/nfs
OPTS_RPC_NFSD="8 -N 2 -V 3 -V 4 -V 4.1"
systemd

The NFS daemon on systemd is configured via the RPCNFSDARGS variable:

ファイル /etc/conf.d/nfs
RPCNFSDARGS="8 -N 2 -V 3 -V 4 -V 4.1"

The option 8 is the number of NFS server threads to start. Since only one thread is started by default, the thread count should be increased for optimal performance. The option -N 2 disables NFS version 2, while options -V 3, -V 4 and -V 4.1 enable NFS versions 3, 4, and 4.1. Refer to man nfsd for more information about the NFS daemon configuration options. Technical differences between major NFS versions explained in the wikipedia article.

サービス

OpenRC

To start the NFS server:

root #rc-service nfs start
 * Starting rpcbind ...                                                   [ ok ]
 * Starting NFS statd ...                                                 [ ok ]
 * Starting idmapd ...                                                    [ ok ]
 * Exporting NFS directories ...                                          [ ok ]
 * Starting NFS mountd ...                                                [ ok ]
 * Starting NFS daemon ...                                                [ ok ]
 * Starting NFS smnotify ...                                              [ ok ]

The above output shows that many other services are also started along with the nfs service. To stop all NFS services, stop the rpcbind service:

root #rc-service rpcbind stop

To start the NFS server at boot:

root #rc-update add nfs default
systemd

To start the NFS server:

root #systemctl start rpcbind nfs-server

To start the NFS server at boot:

root #systemctl enable rpcbind nfs-server

Client

Service

OpenRC

To be able to mount exported directories, start the NFS client:

root #rc-service nfsclient start
 * Starting rpcbind                                                       [ ok ]
 * Starting NFS statd                                                     [ ok ]
 * Starting NFS sm-notify                                                 [ ok ]

To start the NFS client at boot:

root #rc-update add nfsclient default

systemd

The nfs-client service will be started automatically when systemd detects that exported directories are being mounted.

エクスポートをマウントする

注意
The commands and configuration files below use the IPv4 address 192.0.2.1 and IPv6 address2001:db8:1::1 to represent the NFS server.

Mount the exported directories:

root #mount 192.0.2.1:/home /home
root #mount 192.0.2.1:/data /data

To make the above mounts persistent, add the following to /etc/fstab:

ファイル /etc/fstab
192.0.2.1:/home    /home    nfs    rw,_netdev    0    0
192.0.2.1:/data    /data    nfs    rw,_netdev    0    0


root #mount 192.0.2.1:/home -t nfs4 -o _netdev,rsize=1048576,wsize=1048576,vers=4

The virtual root directory can be mounted instead of each individual exported directory. This will make all exported directories available to the client:

root #mount 192.0.2.1:/ /mnt

To make the above mount persistent, add the following to /etc/fstab:

ファイル /etc/fstab
192.0.2.1:/        /mnt     nfs    rw,_netdev    0    0

When using /etc/fstab to mount the exported directories, add the netmount service to the default runlevel:

root #rc-update add netmount default
注意
It will probably be necessary to specify the network management dependencies in /etc/conf.d/netmount.

If the NFS server or client support NFSv3 only, the full path to the exported directory (e.g. /export/home or /export/data) needs to be specified when mounting:

root #mount 192.0.2.1:/export/home /home
root #mount 192.0.2.1:/export/data /data

The same applies when mounting the virtual root directory:

root #mount 192.0.2.1:/export /mnt

When mounting exported directories on an IPv6 network, enclose the IPv6 NFS server address in square brackets:

root #mount [2001:db8:1::1]:/home /home
root #mount [2001:db8:1::1]:/data /data

When mounting a link-local IPv6 address, the outgoing local network interface must also be specified:

root #mount [fe80::215:c5ff:fb3e:e2b1%eth0]:/home /home
root #mount [fe80::215:c5ff:fb3e:e2b1%eth0]:/data /data

With NFSv4, the virtual root directory can be rather 'invisible' depending on server configuration; you may need to use relative path:

root #mount -t nfs4 192.0.2.1:home /home
root #mount -t nfs4 192.0.2.1:data /data
重要
I/O on large files over NFSv4 can be *strongly* improved by the following, which increases the maximum read and write size to 1024^2 bytes, or 1MB.
root #mount 192.0.2.1:/home /home rsize=1048576,wsize=1048576,vers=4

For persistence:

ファイル /etc/fstab
192.0.2.1:/data   /data nfs4 _netdev,rw,rsize=1048576,wsize=1048576,vers=4

Kerberos

It is possible to identify NFS client using Kerberos GSS. This will require a few modifications. In the following instruction, it is supposed that Kerberos is already installed on the same server as NFS (which hostname is server.domain.tld) and that the client (client.domain.tld) is able to kinit to it. The Kerberos default realm it DOMAIN_REALM.TLD.

First, enable the following kernel option (CONFIG_RPCSEC_GSS_KRB5) for both server and client. Note that this option may not appear if all cryptographic dependencies are not selected. See kernel option dependencies for more information:

カーネル Enabling Keberos for RPC
File systems --->
  [*] Network File Systems --->
        <*>   Secure RPC: Kerberos V mechanism

Then, create principals for the NFS service for both the server and the client. On the server, execute:

root #kadmin.local add_principal -randkey nfs/server.domain.tld
root #kadmin.local add_principal -randkey nfs/client.domain.tld

Each computer must have its password saved in a local keytab. The easiest way to do it is (on the server):

root #kadmin.local ktadd nfs/server.domain.tld
root #kadmin.local ktadd -k /root/krb5.keytab nfs/client.domain.tld

and then transfer the /root/krb5.keytab to the client, with the name /etc/krb5.keytab. Note that the file should be owned by root with 0600 mode.

The service rpc.gssd must run at client side. The following line must appear in /etc/conf.d/nfsclient of the client:

ファイル /etc/conf.d/nfsclient
rc_need="!rpc.statd rpc.gssd"

The services rpc.idmapd and rpc.svcgssd must run at server side. The following line must appear in /etc/conf.d/nfs of the server:

ファイル /etc/conf.d/nfs
NFS_NEEDED_SERVICES="rpc.idmapd rpc.svcgssd"

The rpc.idmapd service must be correctly configured (on the server):

ファイル /etc/idmapd.conf
[General]

Domain = domain.tld
Local-Realms = DOMAIN_REALM.TLD

Add sec=krb5 to the export options.

ファイル /etc/exports
/home    192.0.2.0/24(insecure,rw,sync,no_subtree_check,sec=krb5)

It is also possible to increase security with sec=krb5i (user authentication and integrity checking) or even sec=krb5p (user authentication, integrity checking and NFS traffic encryption). The more security, the more resources are needed.

The same option must be added to the mount command at client side.

Troubleshooting

  • The system may become unresponsive during shutdown when the NFS client attempts to unmount exported directories after udev has stopped. To prevent this issue, a local.d script can be used to forcibly unmount the exported directories during shutdown:
ファイル /etc/local.d/nfs.stop
/bin/umount -a -f -t nfs,nfs4
root #chmod a+x /etc/local.d/nfs.stop
  • Verify that the NFS server is running and listening for connections:
root #netstat -tupan | egrep 'rpc|Active|Proto'
Active Internet connections (servers and established)
Proto Recv-Q Send-Q Local Address           Foreign Address         State       PID/Program name
tcp        0      0 0.0.0.0:34950           0.0.0.0:*               LISTEN      1891/rpc.statd
tcp        0      0 0.0.0.0:111             0.0.0.0:*               LISTEN      1875/rpcbind
udp        0      0 0.0.0.0:111             0.0.0.0:*                           1875/rpcbind
udp        0      0 0.0.0.0:57655           0.0.0.0:*                           1891/rpc.statd
udp        0      0 0.0.0.0:774             0.0.0.0:*                           1875/rpcbind
udp        0      0 0.0.0.0:795             0.0.0.0:*                           1891/rpc.statd
  • Verify which NFS daemons are running:
root #rpcinfo -p
   program vers proto   port  service
    100000    4   tcp    111  portmapper
    100000    3   tcp    111  portmapper
    100000    2   tcp    111  portmapper
    100000    4   udp    111  portmapper
    100000    3   udp    111  portmapper
    100000    2   udp    111  portmapper
    100024    1   udp  57655  status
    100024    1   tcp  34950  status
    100003    2   tcp   2049  nfs
    100003    3   tcp   2049  nfs
    100003    4   tcp   2049  nfs
    100003    2   udp   2049  nfs
    100003    3   udp   2049  nfs
    100003    4   udp   2049  nfs
    100021    1   udp  44208  nlockmgr
    100021    3   udp  44208  nlockmgr
    100021    4   udp  44208  nlockmgr
    100021    1   tcp  44043  nlockmgr
    100021    3   tcp  44043  nlockmgr
    100021    4   tcp  44043  nlockmgr
  • List the exported directories from the NFS server:
root #exportfs -v
/export       	192.0.2.0/24(rw,wdelay,crossmnt,insecure,root_squash,no_subtree_check,fsid=0,sec=sys,no_all_squash)
/export/home  	192.0.2.0/24(rw,wdelay,insecure,root_squash,no_subtree_check,sec=sys,no_all_squash)
/export/data  	192.0.2.0/24(rw,wdelay,insecure,root_squash,no_subtree_check,sec=sys,no_all_squash)
  • List the current open connections to the NFS server:
user $netstat -tn | egrep '2049|Active|Proto'
Active Internet connections (w/o servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State      
tcp        0      0 192.0.2.1:2049       192.0.2.10:884        ESTABLISHED
  • Verify that the exported directories are mounted by the NFS client:
user $netstat -tn | egrep '2049|Active|Proto'
Active Internet connections (w/o servers)
Proto Recv-Q Send-Q Local Address           Foreign Address         State
tcp        0      0 192.0.2.10:997        192.0.2.1:2049        ESTABLISHED

See also

  • Samba — a re-implementation of the SMB/CIFS networking protocol, a Microsoft Windows alternative to Network File System (NFS).

External resources

Retrieved from "https://wiki.gentoo.org/index.php?title=Nfs-utils/ja&oldid=1167031"