NBU異機還原oracle，使用者不同問題

今天在執行nbu恢復oracle的問題，發現總是出現問題
恢復指令碼是沒問題的
RMAN> run
{
allocate channel c1 type 'sbt_tape';
send 'NB_ORA_CLIENT=mytest1';
restore controlfile from '/cntrl_6255_1_880381344';
release channel c1;
}

using target database control file instead of recovery catalog
allocated channel: c1
channel c1: SID=59 device type=SBT_TAPE
channel c1: Veritas NetBackup for Oracle - Release 7.6 (2013111313)

sent command to channel: c1

Starting restore at 22-MAY-15

channel c1: restoring control file
released channel: c1
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of restore command at 05/22/2015 14:45:16
ORA-19870: error while restoring backup piece /cntrl_6255_1_880381344
ORA-19507: failed to retrieve sequential file, handle="/cntrl_6255_1_880381344", parms=""
ORA-27029: skgfrtrv: sbtrestore returned error
ORA-19511: Error received from media manager layer, error text:
   Backup file </cntrl_6255_1_880381344> not found in NetBackup catalog
  
但透過bplist從nbu備份伺服器上檢視也是可以看到的，但就是報這個錯，經過分析，感覺可能是使用者的問題，原來備份時的使用者是oracle，而現在的恢復環境是oratest。所以新建新建一個oracle使用者來，建好後對oracle使用者授好權後，再恢復報如下錯誤：
RMAN> run
{
allocate channel c1 type 'sbt_tape';
send 'NB_ORA_CLIENT=mytest1';
restore controlfile from '/cntrl_6255_1_880381344';
release channel c1;
}

using target database control file instead of recovery catalog
allocated channel: c1
channel c1: SID=59 device type=SBT_TAPE
channel c1: Veritas NetBackup for Oracle - Release 7.6 (2013111313)

sent command to channel: c1

Starting restore at 25-MAY-15

released channel: c1
RMAN-00571: ===========================================================
RMAN-00569: =============== ERROR MESSAGE STACK FOLLOWS ===============
RMAN-00571: ===========================================================
RMAN-03002: failure of restore command at 05/25/2015 17:23:18
RMAN-06172: no AUTOBACKUP found or specified handle is not a valid copy or piece

後來經過諮詢nbu的工程師，得到了答案！

原因是：
1、ORACLE_HOME的屬主，要與原環境相同。也就是說原環境中是oracle使用者，那麼新環境也必須是oracle
2、在使用oracle_link連結時，必須是使用與原環境相同的使用者進行執行
2、恢復時，使用的執行使用者，必須與原環境相同的使用者。

這些是nbu沒有公佈的，真坑！