Return-Path: Received: from smtp2.wiktel.com ([69.89.207.152]:33815 "EHLO smtp2.wiktel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752039AbcCHRGK (ORCPT ); Tue, 8 Mar 2016 12:06:10 -0500 Subject: Re: PROBLEM: NFS Client Ignores TCP Resets To: trond.myklebust@primarydata.com, anna.schumaker@netapp.com References: <56BFE55D.1010509@wiktel.com> Cc: linux-nfs@vger.kernel.org From: Richard Laager Message-ID: <56DF067F.4090606@wiktel.com> Date: Tue, 8 Mar 2016 11:06:07 -0600 MIME-Version: 1.0 In-Reply-To: <56BFE55D.1010509@wiktel.com> Content-Type: text/plain; charset=utf-8; format=flowed Sender: linux-nfs-owner@vger.kernel.org List-ID: Is there anything else I can do to help diagnose this? Am I correct in thinking this is a bug? On 02/13/2016 08:24 PM, Richard Laager wrote: > [1.] One line summary of the problem: > > NFS Client Ignores TCP Resets > > [2.] Full description of the problem/report: > > Steps to reproduce: > 1) Mount NFS share from HA cluster with TCP. > 2) Failover the HA cluster. (The NFS server's IP address moves from one > machine to the other.) > 3) Access the mounted NFS share from the client (an `ls` is sufficient). > > Expected results: > Accessing the NFS mount works fine immediately. > > Actual results: > Accessing the NFS mount hangs for 5 minutes. Then the TCP connection > times out, a new connection is established, and it works fine again. > > After the IP moves, the new server responds to the client with TCP RST > packets, just as I would expect. I would expect the client to tear down > its TCP connection immediately and re-establish a new one. But it > doesn't. Am I confused, or is this a bug? > > For the duration of this test, all iptables firewalling was disabled on > the client machine. > > I have a packet capture of a minimized test (just a simple ls): > https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1542826/+attachment/4571304/+files/dovecot-test.upstream-kernel.pcap > > > Note that this is a "single failover" scenario. It is NOT a case of > failing over and then failing back before the TCP connection times out > on the first NFS server. > > [3.] Keywords (i.e., modules, networking, kernel): > > [4.] Kernel version (from /proc/version): > > Linux version 4.5.0-040500rc3-generic (kernel@gomeisa) (gcc version > 5.2.1 20151010 (Ubuntu 5.2.1-22ubuntu2) ) #201602071930 SMP Mon Feb 8 > 00:34:43 UTC 2016 > > [5.] Output of Oops.. message (if applicable) with symbolic information > resolved (see Documentation/oops-tracing.txt) > > N/A. No Oops. > > [6.] A small shell script or example program which triggers the > problem (if possible) > > This is not a self-contained example, but this information may be useful: > > echo 10.20.0.30:/export/krls1/mail /mnt/mail nfs > bg,noacl,noatime,noexec,nordirplus,proto=tcp,vers=3 0 0 >> /etc/fstab > mount /mnt/mail > ls /mnt/mail # Works > # Failover HA cluster > ls /mnt/mail # Hangs for 5 minutes > > [7.] Environment > > $ lsb_release -rd > Description: Ubuntu 15.10 > Release: 15.10 > > [7.1.] Software (add the output of the ver_linux script here) > > $ sh ver_linux > If some fields are empty or look unusual you may have an old version. > Compare to the current minimal requirements in Documentation/Changes. > > Linux dovecot-test 4.5.0-040500rc3-generic #201602071930 SMP Mon Feb 8 > 00:34:43 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux > > GNU C 5.2.1 > GNU Make 4.0 > Binutils 2.25.1 > Util-linux 2.26.2 > Mount 2.26.2 > Module-init-tools 21 > E2fsprogs 1.42.12 > Linux C Library 2.21 > Dynamic linker (ldd) 2.21 > Linux C++ Library 6.0.21 > Procps 3.3.9 > Net-tools 1.60 > Kbd 1.15.5 > Console-tools 1.15.5 > Sh-utils 8.23 > Udev 225 > Wireless-tools 30 > Modules Loaded 8250_fintek autofs4 cirrus drm drm_kms_helper > fb_sys_fops floppy fscache grace i2c_piix4 input_leds ip6table_filter > ip6_tables ip6t_REJECT ip6t_rt iptable_filter ip_tables ipt_REJECT > irqbypass joydev kvm kvm_intel lockd mac_hid nf_conntrack > nf_conntrack_broadcast nf_conntrack_ftp nf_conntrack_ipv4 > nf_conntrack_ipv6 nf_conntrack_netbios_ns nf_defrag_ipv4 nf_defrag_ipv6 > nf_nat nf_nat_ftp nf_reject_ipv4 nf_reject_ipv6 nfs nfs_acl nfsv3 > parport parport_pc pata_acpi ppdev psmouse pvpanic serio_raw sunrpc > syscopyarea sysfillrect sysimgblt ttm x_tables xt_addrtype xt_comment > xt_conntrack xt_hl xt_limit xt_multiport xt_recent xt_tcpudp > > [7.2.] Processor information (from /proc/cpuinfo): > > $ cat /proc/cpuinfo > processor : 0 > vendor_id : GenuineIntel > cpu family : 6 > model : 23 > model name : Intel Core 2 Duo P9xxx (Penryn Class Core 2) > stepping : 3 > microcode : 0x1 > cpu MHz : 2666.764 > cache size : 4096 KB > physical id : 0 > siblings : 1 > core id : 0 > cpu cores : 1 > apicid : 0 > initial apicid : 0 > fpu : yes > fpu_exception : yes > cpuid level : 4 > wp : yes > flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca > cmov pat pse36 clflush mmx fxsr sse sse2 ss syscall nx lm constant_tsc > rep_good nopl pni vmx ssse3 cx16 sse4_1 x2apic hypervisor lahf_lm vnmi ept > bugs : > bogomips : 5333.52 > clflush size : 64 > cache_alignment : 64 > address sizes : 40 bits physical, 48 bits virtual > power management: > > processor : 1 > vendor_id : GenuineIntel > cpu family : 6 > model : 23 > model name : Intel Core 2 Duo P9xxx (Penryn Class Core 2) > stepping : 3 > microcode : 0x1 > cpu MHz : 2666.764 > cache size : 4096 KB > physical id : 1 > siblings : 1 > core id : 0 > cpu cores : 1 > apicid : 1 > initial apicid : 1 > fpu : yes > fpu_exception : yes > cpuid level : 4 > wp : yes > flags : fpu vme de pse tsc msr pae mce cx8 apic sep mtrr pge mca > cmov pat pse36 clflush mmx fxsr sse sse2 ss syscall nx lm constant_tsc > rep_good nopl pni vmx ssse3 cx16 sse4_1 x2apic hypervisor lahf_lm vnmi ept > bugs : > bogomips : 5333.52 > clflush size : 64 > cache_alignment : 64 > address sizes : 40 bits physical, 48 bits virtual > power management: > > [7.3.] Module information (from /proc/modules): > > $ cat /proc/modules > nfsv3 40960 1 - Live 0x0000000000000000 > nfs_acl 16384 1 nfsv3, Live 0x0000000000000000 > nfs 253952 2 nfsv3, Live 0x0000000000000000 > lockd 94208 2 nfsv3,nfs, Live 0x0000000000000000 > grace 16384 1 lockd, Live 0x0000000000000000 > fscache 61440 1 nfs, Live 0x0000000000000000 > ppdev 20480 0 - Live 0x0000000000000000 > kvm_intel 184320 0 - Live 0x0000000000000000 > kvm 561152 1 kvm_intel, Live 0x0000000000000000 > joydev 20480 0 - Live 0x0000000000000000 > input_leds 16384 0 - Live 0x0000000000000000 > irqbypass 16384 1 kvm, Live 0x0000000000000000 > serio_raw 16384 0 - Live 0x0000000000000000 > i2c_piix4 24576 0 - Live 0x0000000000000000 > 8250_fintek 16384 0 - Live 0x0000000000000000 > pvpanic 16384 0 - Live 0x0000000000000000 > parport_pc 32768 0 - Live 0x0000000000000000 > parport 49152 2 ppdev,parport_pc, Live 0x0000000000000000 > mac_hid 16384 0 - Live 0x0000000000000000 > ip6t_REJECT 16384 1 - Live 0x0000000000000000 > nf_reject_ipv6 16384 1 ip6t_REJECT, Live 0x0000000000000000 > xt_hl 16384 22 - Live 0x0000000000000000 > ip6t_rt 16384 3 - Live 0x0000000000000000 > nf_conntrack_ipv6 20480 9 - Live 0x0000000000000000 > nf_defrag_ipv6 36864 1 nf_conntrack_ipv6, Live 0x0000000000000000 > ipt_REJECT 16384 1 - Live 0x0000000000000000 > nf_reject_ipv4 16384 1 ipt_REJECT, Live 0x0000000000000000 > xt_comment 16384 8 - Live 0x0000000000000000 > xt_multiport 16384 2 - Live 0x0000000000000000 > xt_recent 20480 4 - Live 0x0000000000000000 > xt_limit 16384 1 - Live 0x0000000000000000 > xt_tcpudp 16384 26 - Live 0x0000000000000000 > xt_addrtype 16384 4 - Live 0x0000000000000000 > nf_conntrack_ipv4 16384 9 - Live 0x0000000000000000 > nf_defrag_ipv4 16384 1 nf_conntrack_ipv4, Live 0x0000000000000000 > xt_conntrack 16384 18 - Live 0x0000000000000000 > ip6table_filter 16384 1 - Live 0x0000000000000000 > ip6_tables 28672 1 ip6table_filter, Live 0x0000000000000000 > nf_conntrack_netbios_ns 16384 0 - Live 0x0000000000000000 > nf_conntrack_broadcast 16384 1 nf_conntrack_netbios_ns, Live > 0x0000000000000000 > nf_nat_ftp 16384 0 - Live 0x0000000000000000 > nf_nat 24576 1 nf_nat_ftp, Live 0x0000000000000000 > nf_conntrack_ftp 20480 1 nf_nat_ftp, Live 0x0000000000000000 > nf_conntrack 106496 8 > nf_conntrack_ipv6,nf_conntrack_ipv4,xt_conntrack,nf_conntrack_netbios_ns,nf_conntrack_broadcast,nf_nat_ftp,nf_nat,nf_conntrack_ftp, > Live 0x0000000000000000 > iptable_filter 16384 1 - Live 0x0000000000000000 > ip_tables 28672 1 iptable_filter, Live 0x0000000000000000 > x_tables 36864 15 > ip6t_REJECT,xt_hl,ip6t_rt,ipt_REJECT,xt_comment,xt_multiport,xt_recent,xt_limit,xt_tcpudp,xt_addrtype,xt_conntrack,ip6table_filter,ip6_tables,iptable_filter,ip_tables, > Live 0x0000000000000000 > sunrpc 335872 17 nfsv3,nfs_acl,nfs,lockd, Live 0x0000000000000000 > autofs4 40960 2 - Live 0x0000000000000000 > cirrus 28672 1 - Live 0x0000000000000000 > ttm 98304 1 cirrus, Live 0x0000000000000000 > drm_kms_helper 147456 1 cirrus, Live 0x0000000000000000 > syscopyarea 16384 1 drm_kms_helper, Live 0x0000000000000000 > sysfillrect 16384 1 drm_kms_helper, Live 0x0000000000000000 > sysimgblt 16384 1 drm_kms_helper, Live 0x0000000000000000 > fb_sys_fops 16384 1 drm_kms_helper, Live 0x0000000000000000 > floppy 73728 0 - Live 0x0000000000000000 > drm 364544 4 cirrus,ttm,drm_kms_helper, Live 0x0000000000000000 > psmouse 126976 0 - Live 0x0000000000000000 > pata_acpi 16384 0 - Live 0x0000000000000000 > > [7.4.] Loaded driver and hardware information (/proc/ioports, /proc/iomem) > > $ cat /proc/ioports > 0000-0cf7 : PCI Bus 0000:00 > 0000-001f : dma1 > 0020-0021 : pic1 > 0040-0043 : timer0 > 0050-0053 : timer1 > 0060-0060 : keyboard > 0064-0064 : keyboard > 0070-0071 : rtc0 > 0080-008f : dma page reg > 00a0-00a1 : pic2 > 00c0-00df : dma2 > 00f0-00ff : fpu > 0170-0177 : 0000:00:01.1 > 0170-0177 : ata_piix > 01f0-01f7 : 0000:00:01.1 > 01f0-01f7 : ata_piix > 0376-0376 : 0000:00:01.1 > 0376-0376 : ata_piix > 03f2-03f2 : floppy > 03f4-03f5 : floppy > 03f6-03f6 : 0000:00:01.1 > 03f6-03f6 : ata_piix > 03f7-03f7 : floppy > 03f8-03ff : serial > 0cf8-0cff : PCI conf1 > 0d00-adff : PCI Bus 0000:00 > 5658-565b : vmmouse > ae0f-aeff : PCI Bus 0000:00 > af20-afdf : PCI Bus 0000:00 > afe0-afe3 : ACPI GPE0_BLK > afe4-ffff : PCI Bus 0000:00 > b000-b03f : 0000:00:01.3 > b000-b003 : ACPI PM1a_EVT_BLK > b004-b005 : ACPI PM1a_CNT_BLK > b008-b00b : ACPI PM_TMR > b100-b10f : 0000:00:01.3 > b100-b107 : piix4_smbus > c000-c03f : 0000:00:04.0 > c000-c03f : virtio-pci-legacy > c040-c07f : 0000:00:05.0 > c040-c07f : virtio-pci-legacy > c080-c09f : 0000:00:01.2 > c080-c09f : uhci_hcd > c0a0-c0bf : 0000:00:03.0 > c0a0-c0bf : virtio-pci-legacy > c0c0-c0df : 0000:00:06.0 > c0c0-c0df : virtio-pci-legacy > c0e0-c0ff : 0000:00:08.0 > c0e0-c0ff : virtio-pci-legacy > c100-c10f : 0000:00:01.1 > c100-c10f : ata_piix > > $ cat /proc/iomem > 00000000-00000fff : reserved > 00001000-0009fbff : System RAM > 0009fc00-0009ffff : reserved > 000a0000-000bffff : PCI Bus 0000:00 > 000c0000-000c8dff : Video ROM > 000c9000-000c99ff : Adapter ROM > 000ca000-000ca9ff : Adapter ROM > 000cb000-000cd3ff : Adapter ROM > 000f0000-000fffff : reserved > 000f0000-000fffff : System ROM > 00100000-3fffdfff : System RAM > 01000000-018284f9 : Kernel code > 018284fa-01f4497f : Kernel data > 020c3000-02205fff : Kernel bss > 3fffe000-3fffffff : reserved > 40000000-febfffff : PCI Bus 0000:00 > fc000000-fdffffff : 0000:00:02.0 > fc000000-fdffffff : cirrusdrmfb_vram > feb40000-feb7ffff : 0000:00:03.0 > feb80000-febbffff : 0000:00:08.0 > febc0000-febcffff : 0000:00:02.0 > febd0000-febd0fff : 0000:00:02.0 > febd0000-febd0fff : cirrusdrmfb_mmio > febd1000-febd1fff : 0000:00:03.0 > febd2000-febd2fff : 0000:00:04.0 > febd3000-febd3fff : 0000:00:05.0 > febd4000-febd400f : 0000:00:07.0 > febd5000-febd5fff : 0000:00:08.0 > fec00000-fec003ff : IOAPIC 0 > fed00000-fed003ff : HPET 0 > fed00000-fed003ff : PNP0103:00 > fee00000-fee00fff : Local APIC > feffc000-feffffff : reserved > fffc0000-ffffffff : reserved > > [7.5.] PCI information ('lspci -vvv' as root) > > $ sudo lspci -vvv > 00:00.0 Host bridge: Intel Corporation 440FX - 82441FX PMC [Natoma] (rev > 02) > Subsystem: Red Hat, Inc Qemu virtual machine > Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- > Stepping- SERR- FastB2B- DisINTx- > Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- > SERR- Latency: 0 > > 00:01.0 ISA bridge: Intel Corporation 82371SB PIIX3 ISA [Natoma/Triton II] > Subsystem: Red Hat, Inc Qemu virtual machine > Control: I/O+ Mem+ BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- > Stepping- SERR+ FastB2B- DisINTx- > Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=medium >TAbort- > SERR- > 00:01.1 IDE interface: Intel Corporation 82371SB PIIX3 IDE > [Natoma/Triton II] (prog-if 80 [Master]) > Subsystem: Red Hat, Inc Qemu virtual machine > Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- > Stepping- SERR+ FastB2B- DisINTx- > Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- > SERR- Latency: 0 > Region 0: [virtual] Memory at 000001f0 (32-bit, non-prefetchable) > [size=8] > Region 1: [virtual] Memory at 000003f0 (type 3, non-prefetchable) > Region 2: [virtual] Memory at 00000170 (32-bit, non-prefetchable) > [size=8] > Region 3: [virtual] Memory at 00000370 (type 3, non-prefetchable) > Region 4: I/O ports at c100 [size=16] > Kernel driver in use: ata_piix > > 00:01.2 USB controller: Intel Corporation 82371SB PIIX3 USB > [Natoma/Triton II] (rev 01) (prog-if 00 [UHCI]) > Subsystem: Red Hat, Inc QEMU Virtual Machine > Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- > Stepping- SERR+ FastB2B- DisINTx- > Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- > SERR- Latency: 0 > Interrupt: pin D routed to IRQ 10 > Region 4: I/O ports at c080 [size=32] > Kernel driver in use: uhci_hcd > > 00:01.3 Bridge: Intel Corporation 82371AB/EB/MB PIIX4 ACPI (rev 03) > Subsystem: Red Hat, Inc Qemu virtual machine > Control: I/O+ Mem+ BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- > Stepping- SERR+ FastB2B- DisINTx- > Status: Cap- 66MHz- UDF- FastB2B+ ParErr- DEVSEL=medium >TAbort- > SERR- Interrupt: pin A routed to IRQ 9 > Kernel driver in use: piix4_smbus > > 00:02.0 VGA compatible controller: Cirrus Logic GD 5446 (prog-if 00 [VGA > controller]) > Subsystem: Red Hat, Inc QEMU Virtual Machine > Control: I/O+ Mem+ BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- > Stepping- SERR+ FastB2B- DisINTx- > Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- > SERR- Region 0: Memory at fc000000 (32-bit, prefetchable) [size=32M] > Region 1: Memory at febd0000 (32-bit, non-prefetchable) [size=4K] > Expansion ROM at febc0000 [disabled] [size=64K] > Kernel driver in use: cirrus > > 00:03.0 Ethernet controller: Red Hat, Inc Virtio network device > Subsystem: Red Hat, Inc Device 0001 > Physical Slot: 3 > Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- > Stepping- SERR+ FastB2B- DisINTx+ > Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- > SERR- Latency: 0 > Interrupt: pin A routed to IRQ 0 > Region 0: I/O ports at c0a0 [size=32] > Region 1: Memory at febd1000 (32-bit, non-prefetchable) [size=4K] > Expansion ROM at feb40000 [disabled] [size=256K] > Capabilities: [40] MSI-X: Enable+ Count=3 Masked- > Vector table: BAR=1 offset=00000000 > PBA: BAR=1 offset=00000800 > Kernel driver in use: virtio-pci > > 00:04.0 SCSI storage controller: Red Hat, Inc Virtio block device > Subsystem: Red Hat, Inc Device 0002 > Physical Slot: 4 > Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- > Stepping- SERR+ FastB2B- DisINTx+ > Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- > SERR- Latency: 0 > Interrupt: pin A routed to IRQ 0 > Region 0: I/O ports at c000 [size=64] > Region 1: Memory at febd2000 (32-bit, non-prefetchable) [size=4K] > Capabilities: [40] MSI-X: Enable+ Count=2 Masked- > Vector table: BAR=1 offset=00000000 > PBA: BAR=1 offset=00000800 > Kernel driver in use: virtio-pci > > 00:05.0 SCSI storage controller: Red Hat, Inc Virtio block device > Subsystem: Red Hat, Inc Device 0002 > Physical Slot: 5 > Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- > Stepping- SERR+ FastB2B- DisINTx+ > Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- > SERR- Latency: 0 > Interrupt: pin A routed to IRQ 0 > Region 0: I/O ports at c040 [size=64] > Region 1: Memory at febd3000 (32-bit, non-prefetchable) [size=4K] > Capabilities: [40] MSI-X: Enable+ Count=2 Masked- > Vector table: BAR=1 offset=00000000 > PBA: BAR=1 offset=00000800 > Kernel driver in use: virtio-pci > > 00:06.0 Unclassified device [00ff]: Red Hat, Inc Virtio memory balloon > Subsystem: Red Hat, Inc Device 0005 > Physical Slot: 6 > Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- > Stepping- SERR+ FastB2B- DisINTx- > Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- > SERR- Latency: 0 > Interrupt: pin A routed to IRQ 11 > Region 0: I/O ports at c0c0 [size=32] > Kernel driver in use: virtio-pci > > 00:07.0 System peripheral: Intel Corporation 6300ESB Watchdog Timer > Subsystem: Red Hat, Inc QEMU Virtual Machine > Physical Slot: 7 > Control: I/O+ Mem+ BusMaster- SpecCycle- MemWINV- VGASnoop- ParErr- > Stepping- SERR+ FastB2B- DisINTx- > Status: Cap- 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- > SERR- Region 0: Memory at febd4000 (32-bit, non-prefetchable) [size=16] > > 00:08.0 Ethernet controller: Red Hat, Inc Virtio network device > Subsystem: Red Hat, Inc Device 0001 > Physical Slot: 8 > Control: I/O+ Mem+ BusMaster+ SpecCycle- MemWINV- VGASnoop- ParErr- > Stepping- SERR+ FastB2B- DisINTx+ > Status: Cap+ 66MHz- UDF- FastB2B- ParErr- DEVSEL=fast >TAbort- > SERR- Latency: 0 > Interrupt: pin A routed to IRQ 0 > Region 0: I/O ports at c0e0 [size=32] > Region 1: Memory at febd5000 (32-bit, non-prefetchable) [size=4K] > Expansion ROM at feb80000 [disabled] [size=256K] > Capabilities: [40] MSI-X: Enable+ Count=3 Masked- > Vector table: BAR=1 offset=00000000 > PBA: BAR=1 offset=00000800 > Kernel driver in use: virtio-pci > > [7.6.] SCSI information (from /proc/scsi/scsi) > > $ cat /proc/scsi/scsi > Attached devices: > Host: scsi1 Channel: 00 Id: 00 Lun: 00 > Vendor: QEMU Model: QEMU DVD-ROM Rev: 2.0. > Type: CD-ROM ANSI SCSI revision: 05 > > [7.7.] Other information that might be relevant to the problem > (please look in /proc and include all information that you > think to be relevant): > > $ grep mail /proc/mounts > 10.20.0.30:/export/krls1/mail /mnt/mail nfs > rw,noexec,noatime,vers=3,rsize=1048576,wsize=1048576,namlen=255,hard,noacl,nordirplus,proto=tcp,timeo=600,retrans=2,sec=sys,mountaddr=10.20.0.30,mountvers=3,mountport=59274,mountproto=tcp,local_lock=none,addr=10.20.0.30 > 0 0 > > [X.] Other notes, patches, fixes, workarounds: > > This particular system is a virtual machine, but we have seen this on > physical hardware as well. > > If we use UDP instead of TCP, then the NFS client handles the failover > in a timely manner. > > The NFS HA cluster is a system from Nexenta running their latest > software, which is based on Illumos. Our Nexenta reseller's standard > recommendation for HA clusters is to use UDP, because of this behavior. > > For our physical machines acting as virtual hosts, it doesn't make a lot > of difference, but in the virtual machine, I'd especially like to use > TCP, as it performs quite a bit better. > -- Richard