Slow disk write speeds over network
matt at deliver3.com
Mon Jun 9 15:51:55 PDT 2003
On 6/9/03 6:16 PM, "Eric Anderson" <anderson at centtech.com> wrote:
> Chuck Swiger wrote:
>> Eric Anderson wrote:
>>> Ok, I have a file server (NFS) running FreeBSD 4.8-RC1, which is
>>> having incredibly slow disk write speeds. Locally, doing something like:
>>> dd if=/dev/zero of=/partition/testfile
>>> Shows 14MB/s - which is what I expect..
>>> However, ftping a file or cp'ing over NFS shows speeds less than 1MB/s
>>> - which is not what I would expect - it's got gigabit ethernet, and
>>> has very fast read times (via ftp or nfs) over the network.
>> If the slowdown was only with regard to NFS, I'd ask you about what your
>> NFS clients looked like. However, if you're seeing a slowdown for FTP
>> and other network protocols, it's more likely to be a physical problem
>> with cabling, a NIC getting flaky, or something along those lines.
> I see it in both NFS and ftp transfers, but like I said in one of my
> other notes, I have 4 network cards in this machine, all act the same way.
>> Do you have this connected to a managed switch so that you can take a
>> look at the interface statistics for problems? Maybe try cranking the
>> NIC down from gigabit to 100Mbs ethernet speed and see whether that
>> makes a difference?
> Yes - and I just tried that suggestion - same thing. No help.
> Interfaces look ok.
Not to beat a dead horse, but are these the same nics as in the other
machines? Is the switch manageable? Does it agree with the nic(s) on
speed/duplex? Tried turning off autonegotiate and forcing on both sides?
This has all the symptoms of a duplex mismatch.
Matt Levine <matt at deliver3.com>
"The Trouble with doing anything right the first time is that nobody
appreciates how difficult it was." -BIX
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