topic soft Vs Hard mount in Operating System - Linux

soft Vs Hard mount

Chakravarthi — Fri, 24 Sep 2004 09:52:07 GMT

Hi,

which mount to use if i dont want my df and ls commands to hand when the nfs server is not responding

regards
chakri

Re: soft Vs Hard mount

Steven E. Protter — Fri, 24 Sep 2004 11:29:15 GMT

This document,

http://www.tldp.org/HOWTO/NFS-HOWTO/index.html

In the mount section explains some of the implications of this choice.

I think you want to go with soft to accomplish your goal.

Obviously you should run a test and make sure nothing unusual happens.

SEP

Re: soft Vs Hard mount

David Child_1 — Fri, 24 Sep 2004 13:53:42 GMT

Here is some info I found:

soft
If a file request fails, the NFS client will report an error to the process on the client machine requesting the file access. Some programs can handle this with composure, most won't. We do not recommend using this setting; it is a recipe for corrupted files and lost data. You should especially not use this for mail disks --- if you value your mail, that is.

hard
The program accessing a file on a NFS mounted file system will hang when the server crashes. The process cannot be interrupted or killed (except by a "sure kill") unless you also specify intr. When the NFS server is back online the program will continue undisturbed from where it was. We recommend using hard,intr on all NFS mounted file systems.

David

Re: soft Vs Hard mount

Andrew Cowan — Sat, 25 Sep 2004 05:00:07 GMT

You should always bear in mind when you want this mountpoint to be available and what will happen when it isn't? A hard mount is always preferable in a "stable" environment, however you can still fall foul of a dae-lock situation whereby servers can't be rebooted because they're waiting for a mount to become available upon the other. You can set the "interrupt" option to get out of this, however you will still have to be there.

Which-ever way you decide I would never automatically mount an NFS share as part of your boot sequence, and use a script instead. If it is part of a cluster make it an application.

Re: soft Vs Hard mount

R. Sri Ram Kishore_1 — Sat, 25 Sep 2004 13:35:29 GMT

Hi,

Take a look at this thread:
http://forums1.itrc.hp.com/service/forums/questionanswer.do?threadId=682354

And, this is what the mount_nfs(1M) manpage says:
---
Hard versus Soft
File systems that are mounted read-write or that contain executable files should always be mounted with the hard option. Applications using soft mounted file systems may incur unexpected I/O errors, file corruption, and unexpected program core dumps. The soft option is not recommended.
---

HTH.
Regards,
Sri Ram