Present since version 1.8.1. Is it intentional?
Flush all has not been supported by Couchbase since version 1.6 and has been disabled by default in 1.8.1. The reason is that the flush all can cause strange behavior due to the asynchronous nature of the command when combined with a persistent bucket.
If you would still like to use if (I do for testing) then you can reenable it by running the following command:
./cbflushctl localhost:11210 flushall_enabled true
© 2013 COUCHBASE All rights reserved.