[CentOS] NFS help

[m.roth at 5-cent.us]

Larry Martell wrote:
> On Fri, Oct 21, 2016 at 11:21 AM,  <m.roth at 5-cent.us> wrote:
>> Larry Martell wrote:
>>> We have 1 system ruining Centos7 that is the NFS server. There are 50
>>> external machines that FTP files to this server fairly continuously.
>>>
>>> We have another system running Centos6 that mounts the partition the
>>> files
>>> are FTP-ed to using NFS.
>> <snip>
>> What filesystem?
>
> Sorry for being dense, but I am not a sys admin, I am programmer and
> we have no sys admin. I don't know what you mean by your question. I
> am NFS mounting to what ever the default filesystem would be on a
> CentOS6 system.

This *is* a sysadmin issue. Each partition is formatted as a specific type
of filesystem. The standard Linux filesystems for Upsteam-descended have
been ext3, then ext4, and now xfs. Tools to manipulate xfs will not work
with extx, and vice versa.

cat /etc/fstab on the systems, and see what they are. If either is xfs,
and assuming that the systems are on UPSes, then the fstab which controls
drive mounting on a system should have, instead of "defaults",
nobarrier,inode64.

Note that the inode64 is relevant if the filesystem is > 2TB.

The reason I say this is that we we started rolling out CentOS 7, we tried
to put one of our user's home directory on one, and it was a disaster.
100% repeatedly, untarring a 100M tarfile onto an nfs-mounted drive took
seven minutes, where before, it had taken 30 seconds. Timed. It took us
months to discover that NFS 4 tries to make transactions atomic, which is
fine if you're worrying about losing power or connectivity. If you're on a
UPS, and hardwired, adding the nobarrier immediately brought it down to 40
seconds or so.

         mark