Error Message

On Linux system panic'ed with the following stack.

crash> bt
PID: 111303  TASK: ffff885f045b6040  CPU: 1   COMMAND: "bpbkar"
#0 [ffff88481f7cf060] machine_kexec at ffffffff8103fdcb
#1 [ffff88481f7cf0c0] crash_kexec at ffffffff810d1dc2
#2 [ffff88481f7cf190] oops_end at ffffffff8154d110
#3 [ffff88481f7cf1c0] no_context at ffffffff810518cb
#4 [ffff88481f7cf210] __bad_area_nosemaphore at ffffffff81051b55
#5 [ffff88481f7cf260] bad_area at ffffffff81051c7e
#6 [ffff88481f7cf290] __do_page_fault at ffffffff81052483
#7 [ffff88481f7cf3b0] do_page_fault at ffffffff8154f09e
#8 [ffff88481f7cf3e0] page_fault at ffffffff8154c3a5
    [exception RIP: vx_dio_done_xfer+253]
....
#9 [ffff88481f7cf520] vx_dio_physio at ffffffffa073466c [vxfs]
#10 [ffff88481f7cf6f0] vx_pdio_clone_reread at ffffffffa073560f [vxfs]
#11 [ffff88481f7cf860] vx_pdio_wait at ffffffffa073598a [vxfs]
#12 [ffff88481f7cf8b0] vx_pdio_rdwri at ffffffffa0735bac [vxfs]    
#13 [ffff88481f7cf9a0] vx_dio_rdwri at ffffffffa05f5194 [vxfs]
#14 [ffff88481f7cfbe0] vx_dio_read at ffffffffa070b00c [vxfs]
#15 [ffff88481f7cfca0] vx_read1 at ffffffffa070bb0c [vxfs]
#16 [ffff88481f7cfd60] vx_vop_read at ffffffffa06ebc7e [vxfs]
#17 [ffff88481f7cfdc0] vx_read at ffffffffa06ec49b [vxfs]
#18 [ffff88481f7cfef0] vfs_read at ffffffff8119a3a5
#19 [ffff88481f7cff30] sys_read at ffffffff8119a6f1
#20 [ffff88481f7cff80] system_call_fastpath at ffffffff8100b0d2
....

The panic was caused by the following Etrack incident.

Etrack 3950391 - Netbackup 5330 Applicance - kernel panic

vx_parallel_dio is a VxFS kernel module parameter to enable the Parallel Direct I/O.  Parallel Direct I/O is a VxFS feature which can improve the performance of Direct I/O with some specific I/O workloads.   Under normal circumstances vx_parallel_dio will not improve the performance significantly and is not required.

Veritas engineering is working on the fix.  Please disable vx_parallel_dio at the meaning as a workaround.

For example, on Linux set vx_parallel_dio to 0 or just remove the setting from the /etc/modprobe.d/local.conf file.

/etc/modprobe.d/local.conf:
options vxfs  vx_parallel_dio=0