topic Re: Need some clarification about async and sync option of /etc/exports in Operating System - Linux

Need some clarification about async and sync option of /etc/exports

senthil_kumar_1 — Wed, 16 Dec 2009 17:59:22 GMT

Hi All,

what is the purpose of "async" and "sync" of /etc/exports.

Re: Need some clarification about async and sync option of /etc/exports

Michal Kapalka (mikap) — Wed, 16 Dec 2009 18:23:01 GMT

hi,

check this link :

Synchronous vs. Asynchronous Behavior in NFS

http://www.faqs.org/docs/Linux-HOWTO/NFS-HOWTO.html#SYNC-ASYNC

mikap

Re: Need some clarification about async and sync option of /etc/exports

Steven E. Protter — Wed, 16 Dec 2009 21:54:58 GMT

Shalom,

async allows reads and writes at the same time. I/O is duplexed.

sync has lower risk to data, becasue writes gets completed before reads are allowed to happen.

SEP

Re: Need some clarification about async and sync option of /etc/exports

Jeeshan — Thu, 17 Dec 2009 09:38:40 GMT

async- This option allows the NFS server to violate the NFS protocol and reply to requests before any changes made by that request have been committed to stable storage (e.g. disc drive).

sync is the default, and async must be explicit requested if needed. To help make system adminstrators aware of this change, 'exportfs' will issue a warning if neither sync nor async is specified.

Re: Need some clarification about async and sync option of /etc/exports

Kranti Mahmud — Tue, 22 Dec 2009 05:55:21 GMT

Hi Senthil,

Check the below link:
http://nfs.sourceforge.net/nfs-howto/ar01s05.html

Rgds-Kranti

Re: Need some clarification about async and sync option of /etc/exports

GUNASEKARAN_1 — Fri, 25 Dec 2009 12:16:33 GMT

HI Senthil,

Sync-- This option does not allow the server reply to requests before the changes made by the request are written to the disk.

Async-- The NFS server can respond that the data is commited when it really isn't on disk. Thus, when the NFS server crashes, the NFS client does not think it has to re-commit the data

Re: Need some clarification about async and sync option of /etc/exports

Kranti Mahmud — Mon, 04 Jan 2010 05:32:30 GMT

Hi Senthil,

Check the below links:

http://linux.die.net/man/5/exports
http://www.redhat.com/docs/manuals/linux/RHL-9-Manual/custom-guide/s1-nfs-export.html

Rgds-Kranti