为什么 gluster-block 设备上显示 SCSI 写错误？

Issue

• 在一个 OCP 节点的消息文件中，连续出现指向 gluster-block 磁盘设备的 SCSI 写错误：

  Sep 27 03:27:10 host1 kernel: XFS (sdb): Failing async write on buffer block 0x1. Retrying async write.
  Sep 27 03:27:13 host1 kernel: sd 109:0:0:0: [sda] Add. Sense: Write error
  Sep 27 03:27:13 host1 kernel: sd 109:0:0:0: [sda] CDB: Write(10) 2a 00 00 a1 d3 28 00 00 08 00
  Sep 27 03:27:13 host1 kernel: sd 109:0:0:0: [sda] Add. Sense: Write error
  Sep 27 03:27:13 host1 kernel: sd 109:0:0:0: [sda] CDB: Write(10) 2a 00 00 00 20 18 00 00 08 00
  Sep 27 03:27:13 host1 kernel: sd 109:0:0:0: [sda] Add. Sense: Write error
  Sep 27 03:27:13 host1 kernel: sd 109:0:0:0: [sda] CDB: Write(10) 2a 00 00 f0 c7 88 00 00 08 00
  Sep 27 03:27:13 host1 kernel: sd 109:0:0:0: [sda] Add. Sense: Write error
  Sep 27 03:27:13 host1 kernel: sd 109:0:0:0: [sda] CDB: Write(10) 2a 00 00 a0 55 88 00 00 08 00
  Sep 27 03:27:13 host1 kernel: sd 109:0:0:0: [sda] Add. Sense: Write error
  Sep 27 03:27:13 host1 kernel: sd 109:0:0:0: [sda] CDB: Write(10) 2a 00 00 a1 cf a8 00 00 08 00
  Sep 27 03:27:13 host1 kernel: sd 109:0:0:0: [sda] Add. Sense: Write error
  Sep 27 03:27:13 host1 kernel: sd 109:0:0:0: [sda] CDB: Write(10) 2a 00 00 00 1a 38 00 00 08 00
  Sep 27 03:27:13 host1 kernel: sd 109:0:0:0: [sda] Add. Sense: Write error
  Sep 27 03:27:13 host1 kernel: sd 109:0:0:0: [sda] CDB: Write(10) 2a 00 00 a1 cf e0 00 00 08 00
  Sep 27 03:27:13 host1 kernel: sd 109:0:0:0: [sda] Add. Sense: Write error
  Sep 27 03:27:13 host1 kernel: sd 109:0:0:0: [sda] Add. Sense: Write error
  Sep 27 03:27:13 host1 kernel: sd 109:0:0:0: [sda] CDB: Write(10) 2a 00 00 f0 c5 c0 00 00 08 00
  Sep 27 03:27:13 host1 kernel: sd 109:0:0:0: [sda] CDB: Write(10) 2a 00 00 a1 cf b0 00 00 08 00
  Sep 27 03:27:13 host1 kernel: sd 109:0:0:0: [sda] Add. Sense: Write error
  Sep 27 03:27:13 host1 kernel: sd 109:0:0:0: [sda] CDB: Write(10) 2a 00 00 a0 26 b5 00 00 07 00
  Sep 27 03:27:22 host1 kernel: sd 163:0:0:0: [sdb] Add. Sense: Write error
  Sep 27 03:27:22 host1 kernel: sd 163:0:0:0: [sdb] CDB: Write(10) 2a 00 00 00 00 08 00 00 10 00
  Sep 27 03:27:22 host1 kernel: XFS (sdb): Failing async write on buffer block 0x8. Retrying async write.
  Sep 27 03:27:22 host1 kernel: XFS (sdb): Failing async write on buffer block 0x10. Retrying async write.
  

  在上例中，这些消息显示磁盘 sdb 和 sda 中出现这个问题。它们是多路径设备 mpatha 的三个可用路径中的两个：

  multipath -ll
  
  mpatha (36001405ef316567bd45440cae3aa58f9) dm-17 LIO-ORG ,TCMU device
  size=1.0G features='1 queue_if_no_path' hwhandler='1 alua' wp=rw
  |-+- policy='round-robin 0' prio=-1 status=active
  | `- 3:0:0:0 sdb 8:16 active ready running
  |-+- policy='round-robin 0' prio=-1 status=enabled
  | `- 2:0:0:0 sda 8:0  active ready running
  |`-+- policy='round-robin 0' prio=-1 status=enabled
  |  `- 4:0:0:0 sdc 8:32 active ready running
  

  这个设备是一个持久性 gluster-block 卷：

  mount -l | grep -i mpath
  
   /dev/mapper/mpatha on /var/lib/origin/openshift.local.volumes/plugins/kubernetes.io/iscsi/iface-default/10.74.176.231:3260-iqn.2016-12.org.gluster-block:ef316567-bd45-440c-ae3a-a58f922b2229-lun-0 type xfs (rw,relatime,seclabel,attr2,inode64,noquota)
  /dev/mapper/mpatha on /var/lib/origin/openshift.local.volumes/pods/cedd7de2-1a9d-11eb-8bed-fa163eea5134/volumes/kubernetes.io~iscsi/pvc-c74d8637-1a9d-11eb-8bed-fa163eea5134 type xfs (rw,relatime,seclabel,attr2,inode64,noquota)
  

  根据上面的输出，在 Openshift 中这个磁盘映射到持久卷 pvc-c74d8637-1a9d-11eb-8bed-fa163eea5134。

• 为什么会出现这些错误信息？如何解决这个问题？