25
votes
Accepted
How to get NFSv4 idmap working with sec=sys?
There are a couple of things to note when using NFSv4 id mapping on mounts which use the default AUTH_SYS authentication (sec=sys mount option) instead of Kerberos.
NOTE: With AUTH_SYS idmapping only ...
- 15.2k
8
votes
Accepted
implications of using NFSv4 fsid=0 and exporting the NFS root to entire LAN (or not)
The man page for exports says about the fsid parameter
NFS needs to be able to identify each filesystem that it exports. Normally it will use a UUID for the filesystem (if the filesystem has such a ...
- 2,190
8
votes
Accepted
NFS performance over high latency is poor, rsync over ssh is about 100x faster
It seems to me you're trying to use rsync wrong. Rsync's protocol is designed for the exact senario of comparing / synchronising large file systems on two separate servers. It does at much as it can ...
- 19.4k
7
votes
Accepted
Mount NFS - "operation not permitted" in Proxmox container
I found the issue.
Basically, I've created a Debian unprivileged container in Proxmox.
That means NFS is unavailable. Until now, I was unaware of that restriction while using Proxmox containers.
To be ...
- 365
6
votes
Accepted
difference NFS proto and mountproto
In older NFS versions (v2 and v3) there are two distinct RPC services handled by separate software: the "MOUNT" protocol that's used only to obtain the initial filesystem handles from rpc....
- 7,548
5
votes
NFSv4 wrong effective user / owner, sec=krb5 mount squashes to anonymous user
Well, I've figured out that it's worthwhile to understand how NFS and Kerberos deal with users, and how principal names come to play here - topics that are frequently left out in most guides.
In ...
- 81
4
votes
Accepted
Why is NFSv4 not translating POSIX ACL's in a usable way?
My problem turned out to be a failure to understand how POSIX ACLs work; in particular I assumed that default ACLs set permissions on the directory they've been applied to, when in fact these only ...
- 732
3
votes
NFS4, insecure, port number, rdma contradiction help
You have several questions and concerns regarding NFS (Network File System) version 4, its security options, port numbers, and the usage of RDMA (Remote Direct Memory Access).
NFS version 4, ...
- 3,316
3
votes
How can I identify who is writing to NFS server and where are these writes coming from?
I found some good answers in this AskUbuntu question.
I would stress the answer that uses:
iftop -P -i <interface name (e.g. enp1s0)>
to show traffic sorted by volume on a port and then uses:
...
3
votes
difference NFS proto and mountproto
From man 5 nfs:
mountproto=netid
The transport the NFS client uses to transmit requests
to the NFS server's mountd service when performing this
...
- 6,502
2
votes
Why is NFSv4 not translating POSIX ACL's in a usable way?
Something that might be called POSIX ACLs does not exist.
There was a standard proposal draft from aprox. 1993 that was withdrawn in 1997 because users did not like this kind of ACL implementation.
...
- 19.4k
2
votes
NFSv4 mount that works fine for Ubuntu 20.04, fails on RHEL 8.6
Sigh.... All the detail checking before I made this post and I missed the most important part. I would have said that the parameters for the RHEL client were copied from the others and were ...
- 51
2
votes
NFS causes linux system to hang, doing ls or df for example
Next time you have this problem, look into /proc/fs/nfsfs/volumes on server B.
You should find there a list of mounted NFS filesystems, listing a FSID for each. Note the FSIDs of the hanging mount(s). ...
- 103k
2
votes
NFS4, insecure, port number, rdma contradiction help
regarding /proc/fs/nfsd/portlist which is largely the problem
https://patchwork.kernel.org/project/linux-nfs/patch/[email protected]/
the /etc/nfs.conf file in RHEL 8 ...
- 7,423
2
votes
Accepted
Debian 10 fstab - Is there an option to prevent boot sequence hanging when device does not exist?
For automatically mounting NFS when present, autofs can be used (autofs)
As mentioned in man fstab(5)
nofail
do not report errors for this device if it does not exist.
AFAIK nobootwait was only ...
- 3,147
2
votes
Getting NFS RDMA to work in RHEL 8
for those interest, in RHEL 8.7 this is the deal
clean install from rhel-8.7-x86_64-dvd.iso
On the NFS Server side you must edit /etc/nfs.conf and uncomment rdma=n and set that to rdma=y. This does ...
- 7,423
2
votes
Accepted
why is NFS copy speed half that of SSH scp?
The primary cause is probably the fact that the NFS share is mounted with the sync option. This theoretically improves data safety in scenarios where the server might suddenly disappear or the client ...
- 12.3k
2
votes
Accepted
NFS mount mixing up ctime and mtime
From looking at a packet capture in Wireshark, it appears this is a bug in the Linux server, not the FreeBSD client.
I believe this is a bug in Linux kernel commit e377a3e698fb, first included in ...
- 813
2
votes
How to make hardlinks across two NFS shares?
General observation
They are shared separately so the clients can mount them separately.
This reasoning makes little sense. If the parent directory was shared, clients could mount subdirectories ...
- 22.9k
2
votes
Accepted
Why does df shows same as "du --apparent-size"?
The man page for du right in the short description says it estimates file space usage. There are many filesystem features that can make its output inaccurate.
For sparse files, block size would ...
- 7,737
1
vote
How to make hardlinks across two NFS shares?
A usual implementation of most file systems, including a NFS share, defines - like in an oriented object language - a set of operations (open, read...) you can do INSIDE the mounted filesystem. The ...
- 2,808
1
vote
Accepted
does NFS proto=rdma bypass firewalld?
RDMA is technology to by-passing the kernel , and iptables is a module of the linux kernel , so firewalld will not work for any RDMA connections.
- 26
1
vote
NFS4 and remote clients: how to show info?
as NFSv4 only uses port tcp/2049 you can simply check connected nfs clients on the server using:
ss -tano state established sport nfs
- 339
1
vote
Accepted
NFS4 and remote clients: how to show info?
Solution found.
netstat -ta | grep nfsd|grep ESTA|awk '{print $5}'|cut -d : -f 1
or
ss -rta | grep nfsd|grep ESTA|awk '{print $5}'|cut -d : -f 1
and show all my clients connected.
To show the ...
- 12.9k
1
vote
NFS causes linux system to hang, doing ls or df for example
You can sometimes recover it using:
mount -o remount /nfs/mountpoint
If that fails then can force the unmount. NOTE that there is a risk of corruption by doing this - probably same risk as ...
- 392
1
vote
NFS causes linux system to hang, doing ls or df for example
That is kind of the nature of NFS. It was that way in the 90s when I started on Unix.
Have you tried mounting with the -o soft option? See if that helps.
Here's from the man page for nfs:
soft /...
- 179
1
vote
rsync hangs after 100% to-chk output
Try using the ‘sync’ mount option
https://wiki.archlinux.org/title/NFS/Troubleshooting#Intermittent_client_freezes_when_copying_large_files
1
vote
Accepted
samba sharing nfs mounted folder and SELINUX
regarding samba not working with an NFS mounted folder...
getsebool -a | grep samba
by default samba_share_nfs is off.
doing an setsebool -P samba_share_nfs on
fixes that. The -P is for persistence, ...
- 7,423
1
vote
Accepted
getting nfs 4 to work in redhat/centos 7
If the systems that are connecting to the CentOS 7.9 NFS server are older then CentOS 7.0, they will only be able to connect using NFS 4.1 or NFS 3.
To force the system to try NFS4 and version 4.2 ...
1
vote
NFS Mount keeps coming back after deleted
Have you run systemctl daemon-reload after editing /etc/fstab?
In distributions that use systemd, /etc/fstab is parsed by [/usr]/lib/systemd/system-generators/systemd-fstab-generator, which will ...
- 103k
Only top scored, non community-wiki answers of a minimum length are eligible