How to start ARCHIVELOG ?

Hi!

I have a database created with NOARCHIVELOG option. Now, I would like to start ARCHIVELOG. What I have to do exactly? Here is what I've tryied:

Parameters in initxxx.ora:

    log_archive_start       = true
    log_archive_dest        = /users/oracle7/dbs/test7/arch/arch.log
    log_archive_format      = 'log%s_%t.arc'
    log_archive_buffer_size = 32
    log_archive_buffers     = 4

As sqldba:

    sqldba> alter database close;
    sqldba> alter database dismount;
    sqldba> alter database mount exclusive;

    sqldba> alter database archivelog;

    sqldba> shutdown
    sqldba> startup open test7

    sqldba> show parameters arch

    NAME                       TYPE    VALUE
    -------------------------- ------- ------------------------------
    log_archive_buffer_size    integer 32
    log_archive_buffers        integer 4
    log_archive_dest           string  /users/oracle7/dbs/test7/arch/arch.log
    log_archive_format         string  'log%s_%t.arc'
    log_archive_start          boolean TRUE

The /users/oracle7/dbs/test7/arch directory is still void... why ?? Stefano

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