ORA-01115 and ORA-27067 during crash recovery

Yesterday, one of our development server got a power outage because of which all our databases running on that server crashed.

After the server was brought up, I started these databases manually. One of the db refused to startup with normal "startup" command.

Here was the front-end error.

SQL> startup
ORACLE instance started.

Total System Global Area 432013312 bytes
Fixed Size 2169944 bytes
Variable Size 356115368 bytes
Database Buffers 62914560 bytes
Redo Buffers 10813440 bytes
Database mounted.
ORA-01115: IO error reading block from file 2 (block # 575701)
ORA-01110: data file 2: '/mnt/user/oracle/data/initdb/undotbs01.dbf'
ORA-27067: size of I/O buffer is invalid
Additional information: 2
Additional information: 1572864

And here is what I saw in alert.log

ALTER DATABASE OPEN
Wed Mar 12 10:01:14 2008
Beginning crash recovery of 1 threads
parallel recovery started with 2 processes
Wed Mar 12 10:01:15 2008
Started redo scan
Wed Mar 12 10:01:16 2008
Completed redo scan
130874 redo blocks read, 760 data blocks need recovery
Wed Mar 12 10:01:16 2008
Started redo application at
Thread 1: logseq 49756, block 4723
Wed Mar 12 10:01:16 2008
Recovery of Online Redo Log: Thread 1 Group 1 Seq 49756 Reading mem 0
Mem# 0 errs 0: /mnt/filer15adapp/data/adap_dev/redo1.log
Wed Mar 12 10:01:16 2008
Errors in file /mnt/oracle-dev1/admin/adap_dev/bdump/adap_dev_p001_4721.trc:
ORA-01115: IO error reading block from file 2 (block # 575701)
ORA-01110: data file 2: '/mnt/filer15adapp/data/adap_dev/undotbs01.dbf'
ORA-27067: size of I/O buffer is invalid
Additional information: 2
Additional information: 1409024
Wed Mar 12 10:01:19 2008
Aborting crash recovery due to slave death, attempting serial crash recovery
Wed Mar 12 10:01:19 2008
Beginning crash recovery of 1 threads
Wed Mar 12 10:01:19 2008
Started redo scan
Wed Mar 12 10:01:20 2008
Completed redo scan
130874 redo blocks read, 760 data blocks need recovery
Wed Mar 12 10:01:25 2008
Aborting crash recovery due to error 1115
Wed Mar 12 10:01:25 2008
Errors in file /mnt/oracle-dev1/admin/adap_dev/udump/adap_dev_ora_4717.trc:
ORA-01115: IO error reading block from file 2 (block # 575701)
ORA-01110: data file 2: '/mnt/filer15adapp/data/adap_dev/undotbs01.dbf'
ORA-27067: size of I/O buffer is invalid
Additional information: 2
Additional information: 1572864
ORA-1115 signalled during: ALTER DATABASE OPEN...
Wed Mar 12 10:02:37 2008
Shutting down instance: further logons disabled


This was the first time i got this error in my experience. Db being running in noarchive log mode (this being dev server) just added to my worries.

Googling didnt help. After some research work, i encountered a note on metalink Note:423128.1.

Though they didnt explain the cause of the problem, but suggested the workaround.

i.e.

1) Mount the database
2) Issue "recover database" command
-- Wait for "Media recovery complete"
3) alter database open

I'm s not sure about the cause as this Note on metalink refers to a Bug 5362935 - "CRASH RECOVERY FAILS WITH ORA-27067 ERROR", which is closed with status "Suspended, Req'd Info not Avail" and lots of useful information is hidden so people like us, who are not working in Oracle Corp cant see it.