Explanation:
The corefile shows that had daemon and other threads were hung in the /var filesystem. The /var filesystem was using the logging behavior. Logging can cause the filesystem to respond more slowly than normal under load. Suggest turning off logging for the /var / and swap filesystems.


  51 threads in biowait()found.

threads in biowait() by device:
count   device (thread:max idle time)
  11   283(vxio),115001 (0x3002f110640: 5 minutes37.38 seconds) /usr
   8   283(vxio),115002 (0x30002619620: 5minutes 37.26 seconds) /opt
   8   283(vxio),0(0x3000a5d7340: 5 minutes 42.35 seconds)//platform/sun4u-us3/lib/libc_psr.so.1/platform/sun4u-us3/lib/sparcv9/libc_psr.so.1
   5  283(vxio),24005 (0x3000efba3a0: 5 minutes 40.10 seconds)/usr/local/bgs
   4   283(vxio),24010 (0x30006724ca0: 5minutes 40.99 seconds) /opt/mqm
   4   283(vxio),115000(0x30005851660: 5 minutes 42.35 seconds) /var
   3  283(vxio),63005 (0x2a100bfbcc0: 5 minutes 31.00 seconds)/dsgo02/sgo/log
   2   283(vxio),63006 (0x300067252e0: 3minutes 42.43 seconds) /dsgo02/sgo/mqm
   1   283(vxio),24002(0x30006725c40: 2 minutes 14.07 seconds) /opt/tivoli
   1  283(vxio),24006 (0x30003152060: 5 minutes 38.99 seconds)/usr/local/ecc
   1   283(vxio),24001 (0x3000b2e2fe0: 2minutes 23.42 seconds) /usr/local/ccms
   1   283(vxio),24013(0x30002619c60: 5 minutes 37.92 seconds)/usr/local/mqm
   1   283(vxio),63008 (0x30005aa1640: 5minutes 25.65 seconds) /dsgo02/sgo/cduser
   1  283(vxio),63024 (0x30002955900: 5 minutes 32.78 seconds)/dsgo02/sgo/ud72

UFS logging is a UFS file system feature that records file system transactions to a log before applying it to the file system itself. UFS logging is enabled by default starting with Solaris[TM] 9 Update 7 or with Patch ID 113073-09.
In a VERITAS Volume Manager configuration, if the root volume is encapsulated, then the root (/) and user (/usr) file systems are not writable during the early stages of the boot process, when these file systems are being mounted.
As a result, UFS logging will fail.
 

The swap volume is a special case where UFS logging should be explicitly disabled. If /usr is not a separate volume, then there will not be an entry for it in /etc/vfstab. A reboot is necessary after the above changes are made.

Example:
/dev/vx/dsk/bootdg/rootvol  /dev/vx/rdsk/bootdg/rootvol    /        ufs    1  no  nologging
/dev/vx/dsk/bootdg/usr      /dev/vx/rdsk/bootdg/usr        /usr    ufs    2   no  nologging
/dev/vx/dsk/bootdg/var      /dev/vx/rdsk/bootdg/var          /var    ufs    2  no  nologging
/dev/vx/dsk/bootdg/opt      /dev/vx/rdsk/bootdg/usr        /opt    ufs    2  yes   nologging