F12 NFS Failures

[Rick Stevens]

On 11/21/2009 10:41 AM, John Austin wrote:
> On Sat, 2009-11-21 at 11:11 -0700, Greg Woods wrote:
>> On Sat, 2009-11-21 at 10:09 +0000, John Austin wrote:
>>
>>>
>>> When copying a large file (2.7GB) from the server to the
>>> F12 m/c a complete freeze of the F12 machine occurs.
>>
>>
>> I haven't seen freezes, but I have seen corruption when trying to copy
>> large files (e.g. like a DVD iso image) via NFS. In fact, this happened
>> to me when I was trying to install an F12 virtual machine on my F11 box
>> (so I could try it out before deciding whether or not to bite the bullet
>> and upgrade the host OS). I copied over the DVD iso image, then tried to
>> install a VM from it, and it failed the media test. Sure enough, it also
>> failed the sha256sum test. Copying the same DVD iso file via scp instead
>> worked fine. I do not trust NFS for large files.
>>
>> --Greg
>>
>>
>
> Hi Greg
>
> That's interesting and very worrying - surely it can't/shouldn't happen!
>
> I have been using NFS for years for all types/sizes of files and
> never had a problem until the last couple of months.
>
> 1.  The Centos/RHEL 5.3/5.4 kernel had a serious bug that has been fixed with the
> 	latest kernel update
>
> 2.  Now this F12 problem
>
> Surely a very large worldwide community uses NFS ?
>
> OK the F12 case could be my finger trouble or even a hardware problem
>
> I will install F12 on a second machine and test again (against the same server)

Can you verify that you run into the same issue if you run NFS over TCP
as opposed to NFS over UDP (it's an option in the mount command on the
client, use either "proto=tcp" or "proto=udp").

By default, the system queries the server and selects a protocol based
on what's being asked of it.  See the "TRANSPORT METHODS" section of
"man nfs".
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