[DanielP]

As far as i can see, sh -x does not show any errors. However, this is the last lines:

++ export zimbra_uid=1001
++ zimbra_uid=1001
++ export zimbra_user=zimbra
++ zimbra_user=zimbra
++ export zimlet_directory=/opt/zimbra/tomcat/webapps/service/zimlet
++ zimlet_directory=/opt/zimbra/tomcat/webapps/service/zimlet
+ export zmsetvars=true
+ zmsetvars=true
+ zmassert -d /opt/zimbra/mysql
+ '[' -d /opt/zimbra/mysql ']'
+ return
+ zmassert -x /opt/zimbra/mysql/bin/mysqld_safe
+ '[' -x /opt/zimbra/mysql/bin/mysqld_safe ']'
+ return
+ zmassert -r /opt/zimbra/conf/my.cnf
+ '[' -r /opt/zimbra/conf/my.cnf ']'
+ return
++ dirname /opt/zimbra/db/mysql.pid
+ zmassert -d /opt/zimbra/db
+ '[' -d /opt/zimbra/db ']'
+ return
+ cd /opt/zimbra/mysql
zimbra@mail:~> + /opt/zimbra/mysql/bin/mysqld_safe --defaults-file=/opt/zimbra/conf/my.cnf --ledir=/opt/zimbra/mysql/bin
Starting mysqld daemon with databases from /opt/zimbra/db/data
STOPPING server from pid file /opt/zimbra/db/mysql.pid
060112 15:37:01 mysqld ended

So, it seems like it is trying to start, and then stops it immediatly.

Also:
ls db/data/
ib_logfile0 ib_logfile1 ibdata1 mail-bin.000001 mail-bin.000002 mail-bin.index mysql test

All libraries specified in the quickstart should be present.

Update:

mysqld.log shows:
060112 15:40:17 mysqld started
060112 15:40:17 InnoDB: Database was not shut down normally!
InnoDB: Starting crash recovery.
InnoDB: Reading tablespace information from the .ibd files...
InnoDB: Restoring possible half-written data pages from the doublewrite
InnoDB: buffer...
060112 15:40:17 InnoDB: Starting log scan based on checkpoint at
InnoDB: log sequence number 0 36808.
InnoDB: Doing recovery: scanned up to log sequence number 0 43676
060112 15:40:17 InnoDB: Starting an apply batch of log records to the database...
InnoDB: Progress in percents: 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99
InnoDB: Apply batch completed
InnoDB: Last MySQL binlog file position 0 79, file name ./mail-bin.000001
060112 15:40:17 InnoDB: Flushing modified pages from the buffer pool...
060112 15:40:17 InnoDB: Started; log sequence number 0 43676
060112 15:40:17 [ERROR] Fatal error: Can't open privilege tables: Table 'mysql.host' doesn't exist
060112 15:40:17 mysqld ended

Maybe the install did not work as expected?

/D