update : NETDEV WATCHDOG gone after driver update form 2009/8/31 Realtek , but still Disconnects occur and the interface is now flapping up/down. in kernel 2.6.28-15-server the system: Gigabyte GA-EX58-UD5 , CPU: Core i7 - 950, RAM: 6x2GB Corsair TR3X6G1600C8D Onboard two Ethernet controller: Realtek 8111D , 4x1TB in raid10 configuration So the rumors persisted that the realtek driver could solve the problem: ( Sorry it's better but the disconnections are still there ) This is what I did and the results : : I download the new realtek linux driver from the webside : from: : http://www.realtek.com/downloads/downloadsView.aspx?Langid=1&PNid=13&PFid=5&Level=5&Conn=4&DownTypeID=3&GetDown=false#2 name / version / Update time / file size LINUX driver for kernel 2.6.x and 2.4.x (Support x86 and x64) / 8.014.00 / 2009/8/31 / 40KB I installed the build-essential and the linux-headres-2.6.28-15-server # apt-get install build-essential # apt-get install linux-headers I flowed the instructions that came whit the driver now to the letter, see 'realtek driver instructions' Begin the transfer testing of small and large files about 24.000 small files and about 1.000 lage files. Just for loading the system. I used three systems to load the server, two with samba smb and one ssh session, but still the local io restrictions of the workstations prevent me form max loading the server. (I want to use real systems and io and not iperf to load the system for now) The system performed well for about 30Min during heavy load of about 330Mbit/sec on average. Then a disconnect occurred for about 4 minutes after that the system recovered for a wile. It's better but the system is still not stable !!!. / system is not production ready until this problem is solved or a work around is found .!! the “NETDEV WATCHDOG” messages are gone but “r8168: eth0 : link up” and “r8168: eth0: link down” messages have appeared. Additional information lspci -vvv ethtool eth0 The following messages were included after the installation ifconfig eth0 realtek driver update procedure -.-.-.-.-.-.-.-.-.-.-.-.-.-.- lspci -vvv 08:00.0 Ethernet controller: Realtek Semiconductor Co., Ltd. RTL8111/8168B PCI Express Gigabit Ethernet controller (rev 03) Subsystem: Giga-byte Technology Device e000 Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- Stepping- SERR- FastB2B- DisINTx+ Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- SERR- Capabilities: [100] Advanced Error Reporting Capabilities: [140] Virtual Channel Capabilities: [160] Device Serial Number 00-e0-4c-68-00-00-00-03 Kernel driver in use: r8168 Kernel modules: r8168, r8169 # ethtool eth0 Settings for eth0: Supported ports: [ TP ] Supported link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Full Supports auto-negotiation: Yes Advertised link modes: 10baseT/Half 10baseT/Full 100baseT/Half 100baseT/Full 1000baseT/Full Advertised auto-negotiation: Yes Speed: 1000Mb/s Duplex: Full Port: Twisted Pair PHYAD: 0 Transceiver: internal Auto-negotiation: on Supports Wake-on: pumbg Wake-on: g Current message level: 0x00000033 (51) Link detected: yes ---- The following messages were included after the installation : Sep 13 21:04:55 btrbl kernel: [ 18.289945] r8169: eth0: link up Sep 13 21:04:55 btrbl kernel: [ 18.289951] r8169: eth0: link up Sep 13 21:11:59 btrbl kernel: [ 442.422552] r8169 0000:09:00.0: PCI INT A disabled Sep 13 21:11:59 btrbl kernel: [ 442.542552] r8169 0000:08:00.0: PCI INT A disabled Sep 13 21:14:15 btrbl kernel: [ 578.863563] r8168 Gigabit Ethernet driver 8.014.00-NAPI loaded Sep 13 21:14:15 btrbl kernel: [ 578.863580] r8168 0000:08:00.0: PCI INT A -> GSI 16 (level, low) -> IRQ 16 Sep 13 21:14:15 btrbl kernel: [ 578.864429] r8168: This product is covered by one or more of the following patents: US5,307,459, US5 ,434,872, US5,732,094, US6,570,884, US6,115,776, and US6,327,625. Sep 13 21:14:15 btrbl kernel: [ 578.864436] eth0: RTL8168B/8111B at 0xffffc2000007a000, 00:24:1d:79:04:35, IRQ 2293 Sep 13 21:14:15 btrbl kernel: [ 578.890709] r8168: eth0: link up Sep 13 21:14:15 btrbl kernel: [ 578.907807] r8168: eth0: link down Sep 13 21:14:15 btrbl kernel: [ 578.907813] r8168 Copyright (C) 2009 Realtek NIC software team