SUMMARY: Usage of NFS

From: Browett, Darren <dbrowett_at_city.coquitlam.bc.ca>
Date: Fri, 25 Jan 2002 13:53:00 -0800

First, thank you to :alan_at_nabeth.cxo.cpqcorp.net, Steve VanDevender
[stevev_at_hexadecimal.uoregon.edu]
and system administration account [sysadmin_at_astro.su.se]

Summarization :

>From the responses, the big concern is obviously performance, and the
ability of NFS to read and
write the necessary information in a timely fashion.

I will certainly monitor the amount of activity on the drive, as I have
"broken" the NFS system before
with pushing too much data to it.

As for file, it is most likely not a "lock" but a "status" file. I have
noticed it disappears
when I stop the "mrtg" process.

The orignal question and responses follow.

Thanks again

Darren
-----Original Message-----
From: Browett, Darren
Sent: January 24, 2002 10:23 AM
To: Tru64-Unix-Managers (E-mail)
Subject: Usage of NFS


Hi there,

This is more of a general question about the use of NFS as opposed to a
specific Tru64 issue.

I am in the process of setting up a monitoring product called mrtg, which I
am sure some of you
are aware of, I have configured the software such that all the output is
being dumped to a NFS
mounted drive. That way I can access the databases from a different system
(running apache) for reporting purposes.

I have two mrtg daemons running, one every minute, and one every 5 minutes.

One thing I noticed in one of the directories is a file called : .nfsXXXX
This appears to be some kind of a lock file.

The question I have is :

1. Is it okay to dump data continously to a NFS drive.

2. By having a lock (I am assuming that is what .nfsXXXX) on the NFS drive,
will this cause problems for other systems

Thank You

Darren

Responses

------------------------------------------------------------------------
From: alan_at_nabeth.cxo.cpqcorp.net [mailto:alan_at_nabeth.cxo.cpqcorp.net]
Sent: None
To: Browett, Darren
Subject: Re: Usage of NFS



        I think the .nfs files are less lock and more status. You can
        have multiple write streams to a single NFS mount point at the
        same time.

        The issue will be performance. If the application can generate
        data at a rate faster than the capacity of your network interface
        and the remote file system, something in the chain is going to
        be saturated. Saturation causes bottlenecks, which cause
        performance problems. NFS V2 writes must be synchronous,
        which affects the performance of the application and the write
        load on the remote device. Even if the application I/O load
        doesn't directly saturate the network interface or remote
        device, the extra load may do so.

        Any extra load has the potential of causing a problem. You
        need to see if this particular load will cause a problem
        for you.
------------------------------------------------------------------------
-----Original Message-----
From: Steve VanDevender [mailto:stevev_at_hexadecimal.uoregon.edu]
Sent: January 24, 2002 10:46 AM
To: Browett, Darren
Subject: Usage of NFS


> 1. Is it okay to dump data continously to a NFS drive.

Sure.

> 2. By having a lock (I am assuming that is what .nfsXXXX) on the NFS
drive,
> will this cause problems for other systems

It's not a lock file. It's a file that has been unlinked by one of the
NFS clients while still being held open (commonly done for temporary
files). When that happens the NFS server renames the file to a unique
".nfsXXXX" name until the client closes the file.

------------------------------------------------------------------------
----Original Message-----
From: system administration account [mailto:sysadmin_at_astro.su.se]
Sent: January 24, 2002 11:06 AM
To: Browett, Darren
Subject: Re: Usage of NFS


On 2002-01-24 10:22:44 -0800, Browett, Darren wrote:
> I am in the process of setting up a monitoring product called mrtg, which
I
> am sure some of you
> are aware of, I have configured the software such that all the output is
> being dumped to a NFS
> mounted drive. That way I can access the databases from a different
system
> (running apache) for reporting purposes.

NFS writes are more expensive (or less reliable, if you choose not to wait
for them to complete) than NFS reads. So it would be better for you to write
the data to a local drive and export that to the other system for reading.

> One thing I noticed in one of the directories is a file called : .nfsXXXX
> This appears to be some kind of a lock file.

Isn't it rather NFS's way of keeping a link to a file that has been
unlink()ed
but may still be held open by remote clients? (Just so that the filehandle
can survive a server reboot?) Sometimes these are left around and need to
be cleaned up manually; I have seen crontab entries to do just that, along
Received on Fri Jan 25 2002 - 21:53:08 NZDT

This archive was generated by hypermail 2.4.0 : Wed Nov 08 2023 - 11:53:43 NZDT