Dong, Qiu Jian
86fb05065f
Reviewed-by: Eotvos, Oliver <oliver.eotvos@t-systems.com> Co-authored-by: Dong, Qiu Jian <qiujiandong1@huawei.com> Co-committed-by: Dong, Qiu Jian <qiujiandong1@huawei.com>
2.5 KiB
What Should I Do If I/O Suspension Occasionally Occurs When SCSI EVS Disks Are Used?
Symptom
When SCSI EVS disks are used and containers are created and deleted on a CentOS node, the disks are frequently mounted and unmounted. The read/write rate of the system disk may instantaneously surge. As a result, the system is suspended, affecting the normal node running.
When this problem occurs, the following information is displayed in the dmesg log:
Attached SCSI disk task jdb2/xxx blocked for more than 120 seconds.
Example:
Possible Cause
After a PCI device is hot added to BUS 0, the Linux OS kernel will traverse all the PCI bridges mounted to BUS 0 for multiple times, and these PCI bridges cannot work properly during this period. During this period, if the PCI bridge used by the device is updated, due to a kernel defect, the device considers that the PCI bridge is abnormal, and the device enters a fault mode and cannot work normally. If the front end is writing data into the PCI configuration space for the back end to process disk I/Os, the write operation may be deleted. As a result, the back end cannot receive notifications to process new requests on the I/O ring. Finally, the front-end I/O suspension occurs.
Impact
CentOS Linux kernels of versions earlier than 3.10.0-1127.el7 are affected.
Solution
Upgrade the kernel to a later version by resetting the node.