Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Hello, here we have a two nodes setup that are running CentOS 5.4, Xen 3.0 (CentOS RPMs) and DRBD 8.3.2 (again CentOS RPM). Both servers are Dell PowerEdge 1950 servers with two Quad-Core Xeon processors and 32GB of memory. The network card used by DRBD is an Intel 82571EB Gigabit Ethernet card (e1000 driver). Both are connected directly with a crossover cable. DRBD is configured so that I have one resource (drbd0) on which I have configured a LVM VolumeGroup which is then sliced in two LVs. Both LVs are mapped to my Xen VM (PV) as sda and sdb disks. Recently, we've had issues where the node that is in Primary state and hence running the VM locks up and throws a kernel panic. The situation seems to indicate that this might be a problem related to DRBD and/or the network stack because if we disconnect the DRBD resource, this problem will not occur. Even worse, the problem occur very quickly after we connect the DRBD resource, either during resynchronization after being out-of-sync for a while or during normal syncing operations. No errors show up on the network interface (ifconfig, ethtool) One thing to note is that the kernel panic seems to complain about checksum functions so that might be related (see below) Here are the relevant informations # rpm -qa | grep -e xen -e drbd drbd83-8.3.2-6.el5_3 kmod-drbd83-xen-8.3.2-6.el5_3 xen-3.0.3-94.el5 kernel-xen-2.6.18-164.el5 xen-libs-3.0.3-94.el5 # cat /etc/drbd.conf global { usage-count no; } common { protocol C; syncer { rate 33M; verify-alg crc32c; al-extents 1801; } net { cram-hmac-alg sha1; max-epoch-size 8192; max-buffers 8192; } disk { on-io-error detach; no-disk-flushes; no-disk-barrier; no-md-flushes; } } resource drbd0 { device /dev/drbd0; disk /dev/sda6; flexible-meta-disk internal; on node1 { address 10.11.1.1:7788; } on node2 { address 10.11.1.2:7788; } } ### Kernel Panic ### Unable to handle kernel paging request at ffff880011e3cc64 RIP: [<ffffffff80212bad>] csum_partial+0x56/0x4bc PGD ed8067 PUD ed9067 PMD f69067 PTE 0 Oops: 0000 [1] SMP last sysfs file: /class/scsi_host/host0/proc_name CPU 0 Modules linked in: xt_physdev netconsole drbd(U) netloop netbk blktap blkbk ipt_MASQUERADE iptable_nat ip_nat bridge ipv6 xfrm_nalgo crypto_api xt_tcpudp xt_state ip_conntrack_irc xt_conntrack ip_conntrack_ftp xt_mac xt_length xt_limit xt_multiport ipt_ULOG ipt_TCPMSS ipt_TOS ipt_ttl ipt_owner ipt_REJECT ipt_ecn ipt_LOG ipt_recent ip_conntrack iptable_mangle iptable_filter ip_tables nfnetlink x_tables autofs4 dm_mirror dm_multipath scsi_dh video hwmon backlight sbs i2c_ec i2c_core button battery asus_acpi ac parport_pc lp parport joydev ide_cd e1000e cdrom serial_core i5000_edac edac_mc bnx2 serio_raw pcspkr sg dm_raid45 dm_message dm_region_hash dm_log dm_mod dm_mem_cache ata_piix libata shpchp megaraid_sas sd_mod scsi_mod ext3 jbd uhci_hcd ohci_hcd ehci_hcd Pid: 12887, comm: drbd0_receiver Tainted: G 2.6.18-128.1.16.el5xen #1 RIP: e030:[<ffffffff80212bad>] [<ffffffff80212bad>] csum_partial+0x56/0x4bc RSP: e02b:ffff88000c347718 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffff880010ced500 RDX: 00000000000000e7 RSI: 000000000000039c RDI: ffff880011e3cc64 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000025b85e7c R11: 0000000000000002 R12: 0000000000000028 R13: 0000000000000028 R14: ffff88001c56f7b0 R15: 0000000025b85e7c FS: 00002b391e123f60(0000) GS:ffffffff805ba000(0000) knlGS:0000000000000000 CS: e033 DS: 0000 ES: 0000 Process drbd0_receiver (pid: 12887, threadinfo ffff88000c346000, task ffff88001c207820) Stack: 000000000000039c 00000000000005b4 ffffffff8023d496 ffff88001e7e48d8 0000001400000000 ffff8800000003c4 ffff88001c56f7b0 ffff88001e7e48d8 ffff88001e7e48ec ffff88000c3478e8 Call Trace: [<ffffffff8023d496>] skb_checksum+0x11b/0x260 [<ffffffff80411472>] skb_checksum_help+0x71/0xd0 [<ffffffff8853f33e>] :iptable_nat:ip_nat_fn+0x56/0x1c3 [<ffffffff8853f6cf>] :iptable_nat:ip_nat_local_fn+0x32/0xb7 [<ffffffff8023550c>] nf_iterate+0x41/0x7d [<ffffffff8042f004>] dst_output+0x0/0xe [<ffffffff80258b28>] nf_hook_slow+0x58/0xbc [<ffffffff8042f004>] dst_output+0x0/0xe [<ffffffff802359ab>] ip_queue_xmit+0x41c/0x48c [<ffffffff8022c1cb>] local_bh_enable+0x9/0xa5 [<ffffffff8020b6b7>] kmem_cache_alloc+0x62/0x6d [<ffffffff8023668d>] alloc_skb_from_cache+0x74/0x13c [<ffffffff80222a0b>] tcp_transmit_skb+0x62f/0x667 [<ffffffff8043903a>] tcp_retransmit_skb+0x53d/0x638 [<ffffffff80439353>] tcp_xmit_retransmit_queue+0x21e/0x2bb [<ffffffff80225cff>] tcp_ack+0x1705/0x1879 [<ffffffff8021c6b1>] tcp_rcv_established+0x804/0x925 [<ffffffff80263710>] schedule_timeout+0x1e/0xad [<ffffffff8023cef3>] tcp_v4_do_rcv+0x2a/0x2fa [<ffffffff8040bbfe>] sk_wait_data+0xac/0xbf [<ffffffff8029b018>] autoremove_wake_function+0x0/0x2e [<ffffffff80434f71>] tcp_prequeue_process+0x65/0x78 [<ffffffff8021dd39>] tcp_recvmsg+0x492/0xb1f [<ffffffff80233102>] sock_common_recvmsg+0x2d/0x43 [<ffffffff80233102>] sock_common_recvmsg+0x2d/0x43 [<ffffffff80231c18>] sock_recvmsg+0x101/0x120 [<ffffffff80231c18>] sock_recvmsg+0x101/0x120 [<ffffffff8029b018>] autoremove_wake_function+0x0/0x2e [<ffffffff80343366>] swiotlb_map_sg+0xf7/0x205 [<ffffffff880b563c>] :megaraid_sas:megasas_make_sgl64+0x78/0xa9 [<ffffffff880b61bc>] :megaraid_sas:megasas_queue_command+0x343/0x3ed [<ffffffff884e119f>] :drbd:drbd_recv+0x7b/0x109 [<ffffffff884e53b2>] :drbd:receive_DataRequest+0x3b/0x655 [<ffffffff884e1c4b>] :drbd:drbdd+0x77/0x152 [<ffffffff884e4870>] :drbd:drbdd_init+0xea/0x1dc [<ffffffff884f432a>] :drbd:drbd_thread_setup+0xa2/0x18b [<ffffffff80260b2c>] child_rip+0xa/0x12 [<ffffffff884f4288>] :drbd:drbd_thread_setup+0x0/0x18b [<ffffffff80260b22>] child_rip+0x0/0x12 Code: 44 8b 0f ff ca 83 ee 04 48 83 c7 04 4d 01 c8 41 89 d2 41 89 RIP [<ffffffff80212bad>] csum_partial+0x56/0x4bc RSP <ffff88000c347718> CR2: ffff880011e3cc64 Kernel panic - not syncing: Fatal exception ####### Any ideas on how to diagnose this properly and eventually find the culprit? Regards, -- Jean-François Chevrette [iWeb]