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Ci-dessous, les différences entre deux révisions de la page.

--- tech:notes_nfs [2025/10/01 15:54] – Jean-Baptiste
+++ tech:notes_nfs [2026/06/07 19:12] (Version actuelle) – modification externe 127.0.0.1
@@ Ligne 1: / Ligne 1: @@
+<!DOCTYPE markdown>
+{{tag>Brouillon Réseaux FS}}
+# Notes NFS
+Voir :
+* [[NFS - Exécuter NFSv3 derrière un pare-feu]]
+* GPFS
+~~~bash
+findmnt --fstab -t nfs
+~~~
+## Serveur
+Voir :
+* `rclone serv`
+Si SNMP
+`/etc/snmp/snmpd.conf`
+~~~
+skipNFSInHostResources 1
+~~~
+Disable NFS4 delegations
+~~~bash
+# On the NFS server
+echo 0 > /proc/sys/fs/leases-enable
+sysctl -w fs.leases-enable=0
+~~~
+## Client NFS
+Mapper un utilisateur - monter le FS pour un utilisateur précis
+~~~
+all_squash,anonuid=1010,anongid=1010
+~~~
+l'option **no_root_squash** spécifie que le root de la machine sur laquelle le répertoire est monté a les droits de root sur le répertoire). L'option **root_squash** est l'option par défaut
+### NFS3
+Dans les logs Oracle
+~~~
+WARNING:NFS file system /import/oracle/plop mounted with incorrect options(rw,sync,vers=3,rsize=32768,wsize=32768,acregmin=0,acregmax=0,acdirmin=0,acdirmax=0,hard,noac,proto=tcp,timeo=600,retrans=2,sec=sys,addr=sicile)
+WARNING:Expected NFS mount options for ADR directory: rsize>=4096,wsize>=4096,hard
+WARNING:Expected NFS mount options for ADR directory: The 'noac' option should not be set
+WARNING: The directory specified for the diagnostic_dest location has
+WARNING: incorrect mount options. [/app/oracle/oradata/plop/dump]
+~~~
+~~~
+NFSv3
+hard,bg,intr,vers=3,proto=tcp, rsize=32768, wsize=32768,…
+rsize/wsize. Determines the NFS request size for reads/writes. The values of these parameters should match the values for nfs.tcp.xfersize on the NetApp system. A value of 32,768 (32kB) has been shown to maximize database performance in the environment of NetApp and Solaris. In all circumstances, the NFS read/write size should be the same as or greater than the Oracle block size. For example, specifying a DB_FILE_MULTIBLOCK_READ_COUNT of 4 multiplied by a database block size of 8kB results in a read buffer size (rsize) of 32kB.
+NetApp recommended mount options for Oracle single-instance database on Solaris:
+rw,bg,vers=3,proto=tcp,hard,intr,rsize=32768,wsize=32768,forcedirectio
+NetApp recommended mount options for Oracle9i RAC on Solaris:
+rw,bg,vers=3,proto=tcp,hard,intr,rsize=32768,wsize=32768,forcedirectio,noac
+nas1:/shared_config /u01/shared_config  nfs  rw,bg,hard,nointr,tcp,vers=3,timeo=600,rsize=32768,wsize=32768,actimeo=0  0 0
+nas1:/shared_grid   /u01/app/11.2.0/grid  nfs  rw,bg,hard,nointr,tcp,vers=3,timeo=600,rsize=32768,wsize=32768,actimeo=0  0 0
+nas1:/shared_home   /u01/app/oracle/product/11.2.0/db_1  nfs  rw,bg,hard,nointr,tcp,vers=3,timeo=600,rsize=32768,wsize=32768,actimeo=0  0 0
+nas1:/shared_data   /u01/oradata  nfs  rw,bg,hard,nointr,tcp,vers=3,timeo=600,rsize=32768,wsize=32768,actimeo=0  0 0
+~~~
+NFS4
+~~~
+el01sn01:/export/common/patches /u01/common/patches nfs4 rw,bg,hard,nointr,rsize=131072,wsize=131072,proto=tcp
+~~~
+NFS performance can come close to FC
+Requires
+Network topology be clean
+no routers, fast switches
+Mount options correct :
+Rsize / wsize at maximum
+* Avoid actimeo=0 and noac
+* TCP configuration :MTU 9000 (tricky)
+Exemple AWS EFS (NFS)
+~~~bash
+yum install -y nfs-utils
+sudo mount -t nfs4 -o nfsvers=4.1,rsize=1048576,wsize=1048576,hard,timeo=600,retrans=2 MOUNT_TARGET_IP:/ efs
+~~~
+The Amazon EFS client uses the following mount options that are optimized for Amazon EFS:
+* _netdev
+* nfsvers=4.1 – used when mounting on EC2 Linux instances
+* rsize=1048576
+* wsize=1048576
+* hard
+* timeo=600
+* retrans=2
+* noresvport
+~~~bash
+#rpm -ql nfs-utils
+rpm -q --filesbypkg nfs-utils | grep bin
+~~~
+~~~
+nfs-utils                 /sbin/mount.nfs
+nfs-utils                 /sbin/mount.nfs4
+nfs-utils                 /sbin/nfs_cache_getent
+nfs-utils                 /sbin/rpc.statd
+nfs-utils                 /sbin/umount.nfs
+nfs-utils                 /sbin/umount.nfs4
+nfs-utils                 /usr/sbin/exportfs
+nfs-utils                 /usr/sbin/mountstats
+nfs-utils                 /usr/sbin/nfsidmap
+nfs-utils                 /usr/sbin/nfsiostat
+nfs-utils                 /usr/sbin/nfsstat
+nfs-utils                 /usr/sbin/rpc.gssd
+nfs-utils                 /usr/sbin/rpc.idmapd
+nfs-utils                 /usr/sbin/rpc.mountd
+nfs-utils                 /usr/sbin/rpc.nfsd
+nfs-utils                 /usr/sbin/rpc.svcgssd
+nfs-utils                 /usr/sbin/rpcdebug
+nfs-utils                 /usr/sbin/showmount
+nfs-utils                 /usr/sbin/sm-notify
+nfs-utils                 /usr/sbin/start-statd
+~~~
+## Selinux
+~~~bash
+#mount -t nfs -o vers=3,context="system_u:object_r:container_file_t:s0" <server>:/shared_folder /opt/ufm/files
+mount -t nfs4        -o context="system_u:object_r:container_file_t:s0" <server>:/shared_folder /opt/ufm/files
+~~~
+## Diag
+Diag
+~~~bash
+tshark -Y 'tcp.port == 2049' -r tcpdump.pcap > tcpdump.txt
+~~~
+## Pb
+### Pb avec la commande `df`
+A la place il est possible d'utiliser la commande `df -l`
+~~~bash
+sudo umount -a -t nfs -l
+sudo umount -a -t nfs4 -l
+sudo umount -a -t autofs -l
+~~~
+### Err access denied by server while mounting
+~~~
+# mount -t nfs 127.0.0.1:/exports/plop1 /mnt/nfs
+mount.nfs: access denied by server while mounting 127.0.0.1:/exports/plop1
+# chmod 1777 /exports/plop1
+# chmod 1777 /exports
+# mount -t nfs 127.0.0.1:/exports/plop1 /mnt/nfs
+~~~
+### Err Read-only file system
+`/etc/exports`
+~~~
+#specific IP addresses to appear first, IP ranges after.
+#/exports/plop1 192.168.56.0/24(ro,sync,no_subtree_check)
+#/exports/plop1 192.168.56.101(rw,sync,no_subtree_check)
+/exports/plop1 192.168.56.101(rw,sync,no_subtree_check)
+/exports/plop1 192.168.56.0/24(ro,sync,no_subtree_check)
+~~~
+### Pb tail latency
+How do I use the noac option
+Source https://partners-intl.aliyun.com/help/en/nas/latest/67dca4
+#### Problem
+A user mounts the same network file system on two ECS servers (ESC-A and ESC-B). The user writes data in append mode on ECS-A, and monitors file content changes with the `tail -f` command on ECS-B.
+After data is written on ECS-A, the file content changes on ECS-B may experience latency of up to 30 seconds.
+However, if a file is directly opened (such as using `vi`) on ECS-B under the same conditions, the updated content is visible immediately.
+#### Analysis
+This is related to the mount option and the `tail -f` implementation.
+The user uses the following mount command : `mount -t nfs4 /mnt/`
+For file systems mounted on ECS-B using the NFS protocol, the kernel maintains a copy of metadata cache for the file and directory attributes. The cached file and directory attributes (including permission, size, and time stamp) are used to reduce the `NFSPROC_GETATTR RPC` requests.
+The `tail -f` command uses `sleep+fstat` to monitor changes to the file attributes (primarily the file size), read files, and then output the results. However, file content output by using the `tail -f` command is dependent on the `fstat` result. Due to the metadata cache, the `fstat` command may not be monitoring real-time file attributes. Therefore, even if the file has been updated on the NFS server, the `tail -f` command cannot detect in real time whether the file has been changed or not, resulting in the latency.
+#### Solution
+Use the `noac` option of the `mount` command to disable the caching of file and directory attributes. The command is as follows:
+~~~bash
+mount -t nfs4 -o noac /mnt/
+~~~
+## Autres
+Cluster multi DC (NFS4 RH8)
+~~~
+rw, sync, noac, actime=0, _netdev
+~~~
+Option exports : `rw, sync`