Fix speed issue when writing to NAS system

I just fixed an issue with my FreeBSD home server. It is set up as a file server for Mac (AFP) and Linux Clients (NFS). My local network is Gigabit-based sothe limitating factor on read/write speeds should be the hard disk drives in the server.

The server has a Core i3-6100T CPU @ 3.20GHz, 8GB RAM, a ZFS setup with two mirror vdevs each consisting of two disks connected to the board via SATA3. And of course the onboard Gbit NIC (Realtek).

I know very well that write speed was at around 50–60MB/sec, which I would expect. But lately, it dropped amazingly to ~1MB/sec. And I just couldn't think of, why. I suspected the cable, the AFP, the RAM anything.

What I didn't suspect — until today, that is — was the network interface. But I had time today for some googling and even if I didn't found the solution directly, I stumbled across something related to the output of ifconfig. So I hacked that into the console and stared at it.

re0: flags=8843<UP,BROADCAST,RUNNING,SIMPLEX,MULTICAST> metric 0 mtu 1500 options=8209b<RXCSUM,TXCSUM,VLAN_MTU,VLAN_HWTAGGING,VLAN_HWCSUM,WOL_MAGIC,LINKSTATE> ether 4c:cc:6a:b3:3c:f5 hwaddr 4c:cc:6a:b3:3c:f5 inet6 fd23:16:7:7::1 prefixlen 64 inet6 fe80::4ecc:6aff:feb3:3cf5%re0 prefixlen 64 scopeid 0x1 inet 192.168.10.118 netmask 0xffffff00 broadcast 192.168.10.255 nd6 options=21<PERFORMNUD,AUTO_LINKLOCAL> media: Ethernet autoselect (10baseT/UTP <full-duplex>) status: active 

Do you spot it?

 media: Ethernet autoselect (10baseT/UTP <full-duplex>) 

Well, that is … unfortunate. The output of ifconfig -m re0 gave me:

 supported media: media autoselect mediaopt flowcontrol media autoselect media 1000baseT mediaopt full-duplex,flowcontrol,master media 1000baseT mediaopt full-duplex,flowcontrol media 1000baseT mediaopt full-duplex,master media 1000baseT mediaopt full-duplex media 100baseTX mediaopt full-duplex,flowcontrol media 100baseTX mediaopt full-duplex media 100baseTX media 10baseT/UTP mediaopt full-duplex,flowcontrol media 10baseT/UTP mediaopt full-duplex media 10baseT/UTP media none 

So I ran sudo ifconfig re0 media 1000baseTX mediaopt full-duplex and it worked. After that I also ran sudo ifconfig re0 media autoselect which also set the media type to 1000baseT full-duplex. I have no idea why the system did that wrong (or when) but I will monitor what happens after the next reboot. Maybe I have to do some configuration but maybe it was just an hickup.

Speeds are up to 60MB/sec again.