Hello,
tried to simulate some maintenance operations and restart the f18 server where I installed the engine, version
3.2.0-1.20130113.gitc954518

I'm unable to connect to it after 
shutdown -r now

The engine seems started correctly

Even after 

systemctl restart ovirt-engine.service 
I'm not able to connect via web
I can see this in httpd logs:

[Tue Jan 15 13:38:08.512923 2013] [mpm_prefork:notice] [pid 1132] AH00170: caught SIGWINCH, shutting down gracefully
[Tue Jan 15 13:38:50.950219 2013] [core:notice] [pid 1097] SELinux policy enabled; httpd running as context system_u:system_r:httpd_t:s0
[Tue Jan 15 13:38:51.014967 2013] [suexec:notice] [pid 1097] AH01232: suEXEC mechanism enabled (wrapper: /usr/sbin/suexec)
[Tue Jan 15 13:38:52.000997 2013] [ssl:notice] [pid 1097] AH01886: SSL FIPS mode disabled
[Tue Jan 15 13:38:52.146753 2013] [auth_digest:notice] [pid 1097] AH01757: generating secret for digest authentication ...
[Tue Jan 15 13:38:53.000950 2013] [lbmethod_heartbeat:notice] [pid 1097] AH02282: No slotmem from mod_heartmonitor
[Tue Jan 15 13:38:53.001039 2013] [ssl:notice] [pid 1097] AH01886: SSL FIPS mode disabled
[Tue Jan 15 13:38:53.012520 2013] [mpm_prefork:notice] [pid 1097] AH00163: Apache/2.4.3 (Fedora) OpenSSL/1.0.1c-fips configured -- resuming normal operations
[Tue Jan 15 13:38:53.012539 2013] [core:notice] [pid 1097] AH00094: Command line: '/usr/sbin/httpd -D FOREGROUND'

# getenforce 
Permissive

# systemctl status httpd.service
httpd.service - The Apache HTTP Server
 Loaded: loaded (/usr/lib/systemd/system/httpd.service; enabled)
 Active: active (running) since Tue, 2013-01-15 13:38:53 CET; 9min ago
Main PID: 1097 (httpd)
 Status: "Total requests: 0; Current requests/sec: 0; Current traffic:   0 B/sec"
 CGroup: name=systemd:/system/httpd.service
 ├ 1097 /usr/sbin/httpd -DFOREGROUND
 ├ 1267 /usr/sbin/httpd -DFOREGROUND
 ├ 1268 /usr/sbin/httpd -DFOREGROUND
 ├ 1269 /usr/sbin/httpd -DFOREGROUND
 ├ 1270 /usr/sbin/httpd -DFOREGROUND
 └ 1271 /usr/sbin/httpd -DFOREGROUND

Jan 15 13:38:53 f18engine.ceda.polimi.it systemd[1]: Started The Apache HTTP Server.

# systemctl status ovirt-engine.service
ovirt-engine.service - oVirt Engine
 Loaded: loaded (/usr/lib/systemd/system/ovirt-engine.service; enabled)
 Active: active (running) since Tue, 2013-01-15 13:38:53 CET; 9min ago
Process: 1233 ExecStart=/usr/bin/engine-service start (code=exited, status=0/SUCCESS)
Main PID: 1274 (java)
 CGroup: name=systemd:/system/ovirt-engine.service
 └ 1274 engine-service -server -XX:+TieredCompilation -Xms1g -Xmx1g -XX:PermSize=256m -XX:MaxPermSize=256m -D...

Jan 15 13:38:51 f18engine systemd[1]: Starting oVirt Engine...
Jan 15 13:38:53 f18engine engine-service[1233]: Started engine process 1274.
Jan 15 13:38:53 f18engine engine-service[1233]: Starting engine-service: [  OK  ]
Jan 15 13:38:53 f18engine systemd[1]: Started oVirt Engine.

On browser I get after trying 
server is taking to much to answer...

Before shutdown it was ok....