Messages in this thread | ![/](/images/icornerl.gif) | | Date | Tue, 22 Jul 2003 11:06:59 -0700 | From | Samuel Flory <> | Subject | Re: 2.4.21, NFS v3, and 3com 920 |
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Valdis.Kletnieks@vt.edu wrote:
>On Tue, 22 Jul 2003 00:42:45 CDT, Matthew Hunter <matthew@infodancer.org> said: > > > >>Running more tests, it turns out the speed problem is isolated to >>the one machine, and only to *receiving* data. Sending goes at >>8 M/s to other machines from the client machine. Sending from >>any machine to the client machine is slowed down, not just from >>the server. >> >> > >These symptoms sound suspiciously like a 100BaseT auto-negotiation >problem. With some combinations of gear, if one end is set to auto-negotiate >and the other end is nailed to full/half duplex (sorry, can't remember which and >I've not my caffiene yet), things go horribly wrong and many packets >dissapear silently on transmission, forcing retransmit timeouts and bad >throughput. Basically, you end up with one end thinking it's full duplex, >the other end at half - and if the full duplex side ever sends a packet while >the half side is sending, the packet's lost. > >Try nailing the devices on both ends of the cat-5 to the same thing (full or >half). This can of course be interesting if you have an unmanaged hub that >doesn't give you a choice... > > > > >
You should be able to use mii-tool, or ethtool (one or both should work) to check the state your ethernet controller thinks it is set to, and change the settings.
[root@sflory cujo]# mii-tool -v eth0 eth0: negotiated 100baseTx-FD, link ok product info: vendor 00:aa:00, model 51 rev 0 basic mode: autonegotiation enabled basic status: autonegotiation complete, link ok capabilities: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD advertising: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD flow-control link partner: 100baseTx-FD 100baseTx-HD 10baseT-FD 10baseT-HD [root@sflory cujo]# ethtool eth0 Settings for eth0: Supported ports: [ TP MII ] Supported link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full Supports auto-negotiation: Yes Advertised link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full Advertised auto-negotiation: Yes Speed: 100Mb/s Duplex: Full Port: Twisted Pair PHYAD: 1 Transceiver: internal Auto-negotiation: on Supports Wake-on: puag Wake-on: g Link detected: yes [root@sflory cujo]#
-- Once you have their hardware. Never give it back. (The First Rule of Hardware Acquisition) Sam Flory <sflory@rackable.com>
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