Subject: On a hard-mounted file system, NFS operations are retried until they are acknowledged by the server. … If an NFS server goes down, the clients using its file systems hang if they reference these file systems before the server recovers.
Why does NFS mount hang?
New NFS mount attempts, pointing to the same server, may also hang. However, packets on OTHER connections (both new and old) between the same client machine and server machine may be having no problems. … NOTE: There can be many different causes of a hanging NFS mount, or of the “not responding” logs.
Why is NFS bad?
The reason is the NFS write cache, which usually does not get flushed until the file is closed. … So when a client removes a file, it will be gone for good, and the file handle is no longer valid – and and attempt to read from or write to that file will result in a “Stale file handle” error.
How remove NFS mount?
Removing predefined NFS mounts
- Enter the command: umount /directory/to/unmount .
- Open the /etc/filesystems file with your favorite editor.
- Find the entry for the directory you just unmounted, and then delete it.
- Save and close the file.
How do I know if NFS is running?
To verify that NFS is running on each computer:
- AIX® operating systems: Type the following command on each computer: lssrc -g nfs The Status field for NFS processes should indicate active . …
- Linux® operating systems: Type the following command on each computer: showmount -e hostname.
Is NFS unsafe?
NFS is built on the Remote Procedure Call (RPC) mechanism, making it a stateless protocol. In fact, NFS is not stateless from the client point of view, but it is from the server point of view. This means that the server does not keep any information about the clients using it.
Is NFS better than SMB?
NFS offers better performance and is unbeatable if the files are medium-sized or small. For larger files, the timings of both methods are almost the same. In the case of sequential read, the performance of NFS and SMB are almost the same when using plain text. However, with encryption, NFS is better than SMB.
Is NFS still used?
The most common NFS in use today, NFSv3, is 18 years old — and it’s still widely used the world over. … Sure, there are still millions of Unix boxes using NFS, but now there are also millions of virtualized Windows servers that are running from NFS storage through the hypervisor.
Is NFSv4 faster than NFSv3?
NFSv4 file creation is actually about half the speed of file creation over NFSv3, but NFSv4 can delete files quicker than NFSv3. By far the largest speed gains come from running with the async option on, though using this can lead to issues if the NFS server crashes or is rebooted.
What can I use instead of NFS?
Alternatives to NFS include AFS, DFS and RFS.
- AFS – Andrew File System. AFS is a distributed file system that enables co-operating hosts (clients and servers) to efficiently share file system resources across both local area and wide area networks. …
- DFS – Distributed File System. …
- RFS – Remote File Sharing.
How fast is NFS?
The NFS server and client communicate over a 100 MB per second Ethernet network. When sequentially writing a small file, the throughput averages around 10 MB per second. However, when writing a very large file, the throughput average drops to well under 1 MB per second.