[CentOS] Re: exports options

Akemi Yagi amyagi at gmail.com
Sun Mar 25 15:53:56 UTC 2007

On Sun, 25 Mar 2007 14:33:28 +0100, James Pearson wrote:

> On 24/03/07, Akemi Yagi <amyagi at gmail.com>
> wrote:
>> I have been running a local repository on a CentOS4 server.  It serves
>> CentOS4 clients (and FC5, FC6, and SuSE10.x if I bother to mention).  My
>> current options for exports is (ro,wdelay,insecure,root_squash).  The ro
>> and insecure options were added manually and others are default.  I
>> understand 'sync' is the default although it is not shown by exportfs
>> -v. I also found this description in the NFS FAQ:
>> "For the Linux implementation of NFS Version 3, using the "async" export
>> option to allow faster writes is no longer necessary. NFS Version 3
>> explicitly allows a server to reply before writing data to disk, under
>> controlled circumstances. It allows clients and servers to communicate
>> about the disposition of written data so that in the event of a server
>> reboot, a Version 3 client can detect the reboot and resend the data.
>> In summary, be sure all exports on your Linux NFS servers use the "sync"
>> option by setting it explicitly or by upgrading your nfs-utils package
>> to version 1.0.1 or later. If you need fast writes, be sure your clients
>> mount using NFS Version 3. You may also improve write performance by
>> adding the "wdelay" option to your exports."
>> In other words, the default settings (sync and wdelay) seem to be the
>> best choice.  Is this generally true?  Are there any cases in which use
>> of, for example, async is more desirable?
> As you are exporting the file system read-only, then options that effect
> the write performance aren't relevant ...

Thank you for pointing this out.


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