kewastUnPackStats(): bad magic 1資訊說明

在告警日誌中，可能遇到大量如下提示資訊：
Fri Dec 27 08:51:40 2013
kewastUnPackStats(): bad magic 1 (0x0000000067C4BE54, 0)
kewastUnPackStats(): bad magic 1 (0x0000000067C4BE54, 0)
kewastUnPackStats(): bad magic 1 (0x0000000067C4BD04, 0)
kewastUnPackStats(): bad magic 1 (0x0000000067C4BD04, 0)
kewastUnPackStats(): bad magic 1 (0x0000000067C4BE44, 0)
kewastUnPackStats(): bad magic 1 (0x0000000067C4BE44, 0)
kewastUnPackStats(): bad magic 1 (0x0000000067C4BE49, 0)
kewastUnPackStats(): bad magic 1 (0x0000000067C4BE49, 0)
Fri Dec 27 09:18:18 2013
kewastUnPackStats(): bad magic 1 (0x000000006A699AF9, 0)
kewastUnPackStats(): bad magic 1 (0x000000006A699AF9, 0)
kewastUnPackStats(): bad magic 1 (0x000000006A699BF9, 0)
kewastUnPackStats(): bad magic 1 (0x000000006A699BF9, 0)
Fri Dec 27 09:33:52 2013
kewastUnPackStats(): bad magic 1 (0x0000000074FE9E6C, 0)
kewastUnPackStats(): bad magic 1 (0x0000000074FE9E6C, 0)
kewastUnPackStats(): bad magic 1 (0x0000000074FE9D44, 0)
kewastUnPackStats(): bad magic 1 (0x0000000074FE9D44, 0)
kewastUnPackStats(): bad magic 1 (0x0000000074FE9C0C, 0)
kewastUnPackStats(): bad magic 1 (0x0000000074FE9C0C, 0)
kewastUnPackStats(): bad magic 1 (0x0000000074FE9C14, 0)
kewastUnPackStats(): bad magic 1 (0x0000000074FE9C14, 0)

這已經是一個已知的BUG。
這時由於ASH資訊讀取處錯誤導致的。
It is caused by the variable part of the Active Session History rows (the module, action program, etc. information) not being stored properly, causing any read-back of this data through views like (G)V$ACTIVE_SESSION_HISTORY to fail.

還有一個變通的方案就是設定如下引數

Some suggest setting the control_management_pack_access to none as a temporary workaround:

alter system set control_management_pack_access='none' scope=memory;

這個BUG不會引起帶嚴重的問題，打patch  可以解決問題。

參考文件：
"kewastUnPackStats(): bad magic 1 (0xXXXXXXXXX, 0)" in Alert Logfile After Upgrading to 11.2.0.1 (文件 ID 1227524.1)
Bug 8730312 - wrong Null ASH data may cause dumps and kew* messages in alert.log (文件 ID 8730312.8)