集群云盘报错问题排查

当存储和计算分离之后，给容器挂载的硬盘一般是块设备，但这个块设备可能是在其他主机上，使用iscsi协议来读写。

最近遇到一个问题，当iscsi的对应target出问题之后，容器中写盘出现io error，

 [1808657.505206] blk_update_request: critical medium error, dev sdh, sector 4456448
 [1808657.505695] Buffer I/O error on dev sdh, logical block 557056, lost sync page write
 [1808657.506178] JBD2: Error -5 detected when updating journal superblock for sdh-8.
 [1808657.506657] Aborting journal on device sdh-8.
 [1808657.508173] blk_update_request: critical medium error, dev sdh, sector 4456448
 [1808657.508657] Buffer I/O error on dev sdh, logical block 557056, lost sync page write
 [1808657.509152] JBD2: Error -5 detected when updating journal superblock for sdh-8.

[1808657.510929] blk_update_request: critical medium error, dev sdh, sector 0
[1808657.511396] Buffer I/O error on dev sdh, logical block 0, lost sync page write
[1808657.511875] EXT4-fs error (device sdh): ext4_put_super:800: Couldn't clean up the journal
[1808657.512373] EXT4-fs (sdh): Remounting filesystem read-only
[1808657.512869] EXT4-fs (sdh): previous I/O error to superblock detected
[1808657.514869] blk_update_request: critical medium error, dev sdh, sector 0

 [1808657.515402] Buffer I/O error on dev sdh, logical block 0, lost sync page write

[1808657.516635] VFS: Dirty inode writeback failed for block device sdh (err=-5).

 

查这类问题的时候，因为硬盘不在本机，所以需要根据四种持久化命名方案：by-label、by-uuid、by-id 和 by-path等找到对应的硬盘提供侧的宿主机，

然后查看对应的状态即可。