请教大家一下生产环境 Linux 服务器文件系统的一些问题

[zhoudaiyu]

我们的系统盘是 xfs （红帽 7 的操作系统），数据盘 ext4 ，但是昨天机器突然所有进程都 hung 了，CPU 使用率从 40 多降低到了个位数，进程状态基本都为 D ，负载从几十到了 20000 多，系统日志显示 jbd2 卡了 120s ，其他进程也有卡主 120s 的(Flink on K8s)。机器 reboot 之后恢复了，现在怀疑是内核的 ext4 文件系统有问题，但是也不能 100%确定。从我的角度上考虑，可以将 ext4 换成 xfs 去规避问题。请大家给个建议吧，目前看只能长时间用红帽 7 了，内核就到 3.10.1160 了。

[iyiluo]

你应该先怀疑是不是硬盘快坏了，这个几率比遇到文件系统出故障几率大得多

[barrysj]

确实考虑硬盘的问题更大
有监控 cpu iowait 和硬盘的读写延迟之类的数据吗

[zzlyzq]

硬盘可能有故障，而非文件系统问题。

[zhoudaiyu]

@iyiluo #1 当时看带外硬盘信息是正常的，而且 reboot 后恢复了，运行 1 天了也正常了
@barrysj #2 有，从监控数据看到当时有一块盘的 I/O 掉下去了，突然没有读/写了，进程也都 hung 了，iowait 当时没有
硬盘是 3 块 SAS 的 SSD 组的 RAID

[hefish]

op 心里已经有答案了。

[liuchao719]

是有什么需求要用这么低版本的内核嘛，通常来讲开发者对低版本会关照少一些，我觉得能用高版本还是尽量用高版本？因为之前做项目很多问题都是版本过旧引起的，升级一下就没有问题了。

[zhoudaiyu]

@hefish #5 只是怀疑，因为 reboot 了就好了
@liuchao719 #6 没人敢用新系统，没人背得起锅，大家都用老的

[Hormazed]

我们也在用 Red Hat Enterprise Linux Server release 7.9 (Maipo)为了避免内核问题，最近陆续把内核升级到 6.6.8 ，数量已有 20 台左右
Linux version 6.6.8 (root@VTW12NET) (gcc (GCC) 11.2.1 20220127 (Red Hat 11.2.1-9), GNU ld version 2.27-44.base.el7_9.1) #1 SMP PREEMPT_DYNAMIC Thu Dec 20 12:01:06 CST 2023
就我们使用情况来说。没出现过问题，IO 平均每周 300G 。

[Hormazed]

Resolution
Red Hat Enterprise Linux 7

This issue has been resolved with the errata RHSA-2020:1016 for the package(s) kernel-3.10.0-1127.el7 or later.
Red Hat Enterprise Linux 8

This issue has been resolved with the errata RHSA-2019:3517 for the package(s) kernel-4.18.0-147.el8 or later.
Root Cause
Ext4/jbd2 deadlock involving the jdb2 checkpoint thread and the jdb2 commit thread.
Each thread is waiting for the other to move forward:
The checkpoint thread aquires the and waits for the commit thread to finish ( waitqueue), but the commit thread cannot progress since it's trying to acquire the same mutex () owned by the checkpoint thread, leading to the deadlock.j_checkpoint_mutexj_wait_done_commitj_checkpoint_mutex
The deadlock is resolved by upstream commit 53cf978457325d8fb2cdecd7981b31a8229e446e (jbd2: fix deadlock while checkpoint thread waits commit thread to finish).
On Red Hat Enterprise Linux 7, the patch resolving this issue has been backported as part of a more general update in (private) BZ 1747387 - ext4 jbd2: stable update for 7.8
On Red Hat Enterprise Linux 8, the patch resolving this issue has been backported as part of a more general update in (private) BZ 1698815 - [ext4][jbd2] Stable update for rhel8.1

[Kumo31]

给出的信息太少 不足以判断是哪里的问题。不过不用迷信内核，这么老的内核版本 bug 可不少，我们做存储碰上过一篮子的各种内核 bug

[JackSlowFcck]

要不，换块硬盘试试？

[zhoudaiyu]

@Hormazed #8 生产系统不是非常敢用 elrepo 提供的内核，尽管我也想用新的
@Hormazed #9 我们的内核版本已经比这个新了，是 1160
@JackSlowFcck #11 周期太长了，机器托管到别的机房了，现在有的业务是单点，只能先再用上了
@Kumo31 #10 大概率我们要 3.10 一直用上去了，我们还有信创的机器是 4.19 的内核，也反馈过 bug ，厂商也没管

[lrvy]

RHEL 的话直接找售后查😁

[ruidoBlanco]

用红帽，内核问题，首先选择升级内核到当前版本最新看看还有没有问题，其次是找红帽，问社区能有多大用处？

即便是问社区，日志什么也不贴，让人猜？

[zhoudaiyu]

@ruidoBlanco 一会就补上老哥
@lrvy 一言难尽，反正就是能用红帽的包，但是人家不管我们出的问题

[julyclyde]

-t long 诊断一下吧
不应该没问题

[msg7086]

不敢用 elrepo 的内核的话，那要不要看看 UEK 内核？

[zhoudaiyu]

hang 住时候的内核日志截取了部分
Aug 15 09:33:53 node16 kernel: INFO: task jbd2/dm-2-8:1839 blocked for more than 120 seconds.
Aug 15 09:33:53 node16 kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
Aug 15 09:33:53 node16 kernel: jbd2/dm-2-8 D ffff8e7efea1acc0 0 1839 2 0x00000000
Aug 15 09:33:53 node16 kernel: Call Trace:
Aug 15 09:33:53 node16 kernel: [<ffffffff8e8d2ba0>] ? task_rq_unlock+0x20/0x20
Aug 15 09:33:53 node16 kernel: [<ffffffff8ef87169>] schedule+0x29/0x70
Aug 15 09:33:53 node16 kernel: [<ffffffffc118433c>] jbd2_journal_commit_transaction+0x23c/0x19c0 [jbd2]
Aug 15 09:33:53 node16 kernel: [<ffffffff8e8e111e>] ? account_entity_dequeue+0xae/0xd0
Aug 15 09:33:53 node16 kernel: [<ffffffff8e8e48bc>] ? dequeue_entity+0x11c/0x5c0
Aug 15 09:33:53 node16 kernel: [<ffffffff8e8e5ec1>] ? put_prev_entity+0x31/0x400
Aug 15 09:33:53 node16 kernel: [<ffffffff8e82b59e>] ? __switch_to+0xce/0x580
Aug 15 09:33:53 node16 kernel: [<ffffffff8e8c6d10>] ? wake_up_atomic_t+0x30/0x30
Aug 15 09:33:53 node16 kernel: [<ffffffff8ef86c8f>] ? __schedule+0x3af/0x860
Aug 15 09:33:53 node16 kernel: [<ffffffff8e8adf0e>] ? try_to_del_timer_sync+0x5e/0x90
Aug 15 09:33:53 node16 kernel: [<ffffffffc118af89>] kjournald2+0xc9/0x260 [jbd2]
Aug 15 09:33:53 node16 kernel: [<ffffffff8e8c6d10>] ? wake_up_atomic_t+0x30/0x30
Aug 15 09:33:53 node16 kernel: [<ffffffffc118aec0>] ? commit_timeout+0x10/0x10 [jbd2]
Aug 15 09:33:53 node16 kernel: [<ffffffff8e8c5c21>] kthread+0xd1/0xe0
Aug 15 09:33:53 node16 kernel: [<ffffffff8e8c5b50>] ? insert_kthread_work+0x40/0x40
Aug 15 09:33:53 node16 kernel: [<ffffffff8ef93ddd>] ret_from_fork_nospec_begin+0x7/0x21
Aug 15 09:33:53 node16 kernel: [<ffffffff8e8c5b50>] ? insert_kthread_work+0x40/0x40
Aug 15 09:33:53 node16 kernel: INFO: task containerd:225811 blocked for more than 120 seconds.
Aug 15 09:33:53 node16 kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
Aug 15 09:33:53 node16 kernel: containerd D ffff8e7efef1acc0 0 225811 1 0x00000080
Aug 15 09:33:53 node16 kernel: Call Trace:
Aug 15 09:33:53 node16 kernel: [<ffffffff8ef87169>] schedule+0x29/0x70
Aug 15 09:33:53 node16 kernel: [<ffffffffc1181085>] wait_transaction_locked+0x85/0xd0 [jbd2]
Aug 15 09:33:53 node16 kernel: [<ffffffff8e8c6d10>] ? wake_up_atomic_t+0x30/0x30
Aug 15 09:33:53 node16 kernel: [<ffffffffc1181378>] add_transaction_credits+0x278/0x310 [jbd2]
Aug 15 09:33:53 node16 kernel: [<ffffffff8ea2830b>] ? __kmalloc+0x1eb/0x230
Aug 15 09:33:53 node16 kernel: [<ffffffffc11dd8c4>] ? ext4_htree_store_dirent+0x34/0x120 [ext4]
Aug 15 09:33:53 node16 kernel: [<ffffffffc1181601>] start_this_handle+0x1a1/0x430 [jbd2]
Aug 15 09:33:53 node16 kernel: [<ffffffff8ea287c2>] ? kmem_cache_alloc+0x1c2/0x1f0
Aug 15 09:33:53 node16 kernel: [<ffffffffc1181ab3>] jbd2__journal_start+0xf3/0x1f0 [jbd2]
Aug 15 09:33:53 node16 kernel: [<ffffffffc11eb0ba>] ? ext4_dirty_inode+0x2a/0x60 [ext4]
Aug 15 09:33:53 node16 kernel: [<ffffffffc1217759>] __ext4_journal_start_sb+0x69/0xe0 [ext4]
Aug 15 09:33:53 node16 kernel: [<ffffffffc11eb0ba>] ext4_dirty_inode+0x2a/0x60 [ext4]
Aug 15 09:33:53 node16 kernel: [<ffffffff8ea7f00d>] __mark_inode_dirty+0x15d/0x270
Aug 15 09:33:53 node16 kernel: [<ffffffff8ea6b8e9>] update_time+0x89/0xd0
Aug 15 09:33:53 node16 kernel: [<ffffffff8ea6bdfa>] touch_atime+0x10a/0x220
Aug 15 09:33:53 node16 kernel: [<ffffffff8ea63694>] iterate_dir+0xe4/0x130
Aug 15 09:33:53 node16 kernel: [<ffffffff8ea63c8c>] SyS_getdents64+0x9c/0x120
Aug 15 09:33:53 node16 kernel: [<ffffffff8ea63900>] ? fillonedir+0x110/0x110
Aug 15 09:33:53 node16 kernel: [<ffffffff8ef93f92>] system_call_fastpath+0x25/0x2a
Aug 15 09:33:53 node16 kernel: INFO: task containerd:2700571 blocked for more than 120 seconds.
Aug 15 09:33:53 node16 kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
Aug 15 09:33:53 node16 kernel: containerd D ffff8e3eff79acc0 0 2700571 1 0x00000080
Aug 15 09:33:53 node16 kernel: Call Trace:
Aug 15 09:33:53 node16 kernel: [<ffffffff8ef87169>] schedule+0x29/0x70
Aug 15 09:33:53 node16 kernel: [<ffffffffc1181085>] wait_transaction_locked+0x85/0xd0 [jbd2]
Aug 15 09:33:53 node16 kernel: [<ffffffff8e8c6d10>] ? wake_up_atomic_t+0x30/0x30
Aug 15 09:33:53 node16 kernel: [<ffffffffc1181378>] add_transaction_credits+0x278/0x310 [jbd2]
Aug 15 09:33:53 node16 kernel: [<ffffffff8ef86c8f>] ? __schedule+0x3af/0x860
Aug 15 09:33:53 node16 kernel: [<ffffffffc1181601>] start_this_handle+0x1a1/0x430 [jbd2]
Aug 15 09:33:53 node16 kernel: [<ffffffff8ef87169>] ? schedule+0x29/0x70
Aug 15 09:33:53 node16 kernel: [<ffffffff8ef84c51>] ? schedule_timeout+0x221/0x2d0
Aug 15 09:33:53 node16 kernel: [<ffffffff8ea287c2>] ? kmem_cache_alloc+0x1c2/0x1f0
Aug 15 09:33:53 node16 kernel: [<ffffffffc1181ab3>] jbd2__journal_start+0xf3/0x1f0 [jbd2]
Aug 15 09:33:53 node16 kernel: [<ffffffffc11eb0ba>] ? ext4_dirty_inode+0x2a/0x60 [ext4]
Aug 15 09:33:53 node16 kernel: [<ffffffffc1217759>] __ext4_journal_start_sb+0x69/0xe0 [ext4]
Aug 15 09:33:53 node16 kernel: [<ffffffffc11eb0ba>] ext4_dirty_inode+0x2a/0x60 [ext4]
Aug 15 09:33:53 node16 kernel: [<ffffffff8ea7f00d>] __mark_inode_dirty+0x15d/0x270
Aug 15 09:33:53 node16 kernel: [<ffffffff8ea6b8e9>] update_time+0x89/0xd0
Aug 15 09:33:53 node16 kernel: [<ffffffff8eb8cfe4>] ? __radix_tree_lookup+0x84/0xf0
Aug 15 09:33:53 node16 kernel: [<ffffffff8ea6b9d0>] file_update_time+0xa0/0xf0
Aug 15 09:33:53 node16 kernel: [<ffffffff8e9c03d8>] __generic_file_aio_write+0x198/0x400
Aug 15 09:33:53 node16 kernel: [<ffffffff8e9c0699>] generic_file_aio_write+0x59/0xa0
Aug 15 09:33:53 node16 kernel: [<ffffffffc11de5c8>] ext4_file_write+0x348/0x600 [ext4]
Aug 15 09:33:53 node16 kernel: [<ffffffff8ea010bc>] ? page_add_file_rmap+0x8c/0xc0
Aug 15 09:33:53 node16 kernel: [<ffffffff8e9f339e>] ? do_numa_page+0x1be/0x250
Aug 15 09:33:53 node16 kernel: [<ffffffff8ea4d063>] do_sync_write+0x93/0xe0
Aug 15 09:33:53 node16 kernel: [<ffffffff8ea4db50>] vfs_write+0xc0/0x1f0
Aug 15 09:33:53 node16 kernel: [<ffffffff8ea4eaf2>] SyS_pwrite64+0x92/0xc0
Aug 15 09:33:53 node16 kernel: [<ffffffff8ef93f92>] system_call_fastpath+0x25/0x2a
Aug 15 09:33:53 node16 kernel: INFO: task dcgm-exporter:68381 blocked for more than 120 seconds.
Aug 15 09:33:53 node16 kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
Aug 15 09:33:53 node16 kernel: dcgm-exporter D ffff8e3eff81acc0 0 68381 57193 0x00000080
Aug 15 09:33:53 node16 kernel: Call Trace:
Aug 15 09:33:53 node16 kernel: [<ffffffff8ef87169>] schedule+0x29/0x70
Aug 15 09:33:53 node16 kernel: [<ffffffffc1181085>] wait_transaction_locked+0x85/0xd0 [jbd2]
Aug 15 09:33:53 node16 kernel: [<ffffffff8e8c6d10>] ? wake_up_atomic_t+0x30/0x30
Aug 15 09:33:53 node16 kernel: [<ffffffffc1181378>] add_transaction_credits+0x278/0x310 [jbd2]
Aug 15 09:33:53 node16 kernel: [<ffffffffc1181601>] start_this_handle+0x1a1/0x430 [jbd2]
Aug 15 09:33:53 node16 kernel: [<ffffffff8e8e8a43>] ? load_balance+0x1a3/0xa10
Aug 15 09:33:53 node16 kernel: [<ffffffff8ea287c2>] ? kmem_cache_alloc+0x1c2/0x1f0
Aug 15 09:33:53 node16 kernel: [<ffffffffc1181ab3>] jbd2__journal_start+0xf3/0x1f0 [jbd2]
Aug 15 09:33:53 node16 kernel: [<ffffffffc11eb0ba>] ? ext4_dirty_inode+0x2a/0x60 [ext4]
Aug 15 09:33:53 node16 kernel: [<ffffffffc1217759>] __ext4_journal_start_sb+0x69/0xe0 [ext4]
Aug 15 09:33:53 node16 kernel: [<ffffffffc11eb0ba>] ext4_dirty_inode+0x2a/0x60 [ext4]
Aug 15 09:33:53 node16 kernel: [<ffffffff8ea7f00d>] __mark_inode_dirty+0x15d/0x270
Aug 15 09:33:53 node16 kernel: [<ffffffff8ea6b8e9>] update_time+0x89/0xd0
Aug 15 09:33:53 node16 kernel: [<ffffffff8ea6b9d0>] file_update_time+0xa0/0xf0
Aug 15 09:33:53 node16 kernel: [<ffffffff8e9c03d8>] __generic_file_aio_write+0x198/0x400
Aug 15 09:33:53 node16 kernel: [<ffffffff8e9c0699>] generic_file_aio_write+0x59/0xa0
Aug 15 09:33:53 node16 kernel: [<ffffffffc11de5c8>] ext4_file_write+0x348/0x600 [ext4]
Aug 15 09:33:53 node16 kernel: [<ffffffff8e9f339e>] ? do_numa_page+0x1be/0x250
Aug 15 09:33:53 node16 kernel: [<ffffffff8ea4d063>] do_sync_write+0x93/0xe0
Aug 15 09:33:53 node16 kernel: [<ffffffff8ea4db50>] vfs_write+0xc0/0x1f0
Aug 15 09:33:53 node16 kernel: [<ffffffff8ea4e92f>] SyS_write+0x7f/0xf0
Aug 15 09:33:53 node16 kernel: [<ffffffff8ef93f92>] system_call_fastpath+0x25/0x2a
Aug 15 09:33:53 node16 kernel: INFO: task gcs_server:21032 blocked for more than 120 seconds.

[ruidoBlanco]

@zhoudaiyu 升级内核吧。不像是什么简单能解的。即便能定位到 bug ，最后一定还是得升内核。

[zhoudaiyu]

@ruidoBlanco #19 已经是 1160 了，是红帽 7 的最新的内核了，再升就得用 elrepo 或者楼上说的 uek 内核了，领导估计不大支持升级