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

[senthil_kumar_1]

Hi All,

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

[Michal Kapalka (mikap) · Accepted solution]

hi,

check this link :

Synchronous vs. Asynchronous Behavior in NFS

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

mikap

[Steven E. Protter]

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

[Jeeshan]

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.

[Kranti Mahmud]

Hi Senthil,

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

Rgds-Kranti

[GUNASEKARAN_1]

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

[Kranti Mahmud]

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