If asynchronous I/O is enabled, the bpbkar process may hang and can not be killed, requiring a reboot of the system in order to recover.

Problem

If asynchronous I/O is enabled, the bpbkar process may hang and can not be killed, requiring a reboot of the system in order to recover.

Error Message

The bpbkar will report an error reading a file:

16:51:48.621 [277] <16>bpbkar process_file: ERR - Read error at byte 0 reading 23552 bytes in file/BCV/oracle/arch1234.dbf. Errno = -1:

Then, nothing else for that pid.

Cause

On HP-UX 11.11, on rare occasions,the bpbkar process has been seen to hang requiring a reboot of the system to recover if asynchronous I/O is enabled.

Troubleshooting:
A truss of the active bpbkar process may show many of the following type messages:

aio_error64(0x400658d0)........................ ERR#22 EINVAL

Solution

It is possible to resolve this issue by creating the file /usr/openv/netbackup/AIO_READS_MAX with content of the number 1 to disable asynchronous I/O.

echo 1 > /usr/openv/netbackup/AIO_READS_MAX

Note: Be aware this can impact the speed of the backups.