Cannot allocate new log

Question

Hello,
I use Oracle 10.2. I have 3 redo groups, two members in each. I lost member of redo2 group, added it (alter system drop logfile member/alter system add logfile member). NOw I am getting alerts:
Thread 1 advanced to log sequence xx
Current log# 2 seq# (...) /redo02.log
Current log# 2 seq# (...) /redo02b.log <- this is the one that was lost
Thread 1 cannot allocate new log, sequence xxx
Checkpoint not complete
Current log# 2 seq# (...) /redo02.log
Current log# 2 seq# (...) /redo02b.log
Tue Mar 04 (..)
Thread 1 advanced to log sequence xxx
Current log# 3 seq# (...) /redo03.log
Current log# 3 seq# (...) /redo03b.log
I've read previous posts about it, but my problems seems to me to be different, because before losing that redo member I didn't have any alerts. Only after adding it again I have. I neither change anything in number of redo groups nor in redo member sizes.
Greets
A.

Answer 1

The message has nothing to do with your dropping and adding a member.
The "checkpoint not complete" indicates that the Checkpoint that Oracle
implicitly issued when switching out of a log group hadn't completed by the
time the logwriter came around back to the same log group.
The checkpoint is taking approximately the same time as it takes the logwriter
to cycle through your 3 groups. Group 2 just happens to be the boundary case.
You should either
a Add more groups
b Add new groups of larger sizes and drop the existing groups (of smaller sizes).