Por que meu mac mini é desligado aleatoriamente?

Eu tenho um Mac Mini final de 2012 executando a 10.10.2 que eu uso como servidor na minha rede doméstica.

Alguns meses atrás, comecei a encontrá-lo desativado em momentos que parecem aleatórios. Ele não está conectado a um monitor, então eu nunca testemunhei o desligamento.

Pensei em duas razões possíveis:

• Configurações de economia de energia que causam o desligamento. Eles parecem bem para mim, mas eu posso estar fazendo algo errado. Tentei desconectar o USB do UPC para removê-lo da equação. Ainda desliga.
• Falha catastrófica causando o desligamento.

Onde eu começaria a procurar diagnosticar isso? Se for um acidente ou um desligamento com economia de energia, qual registro seria um bom lugar para ver a última coisa que aconteceu antes do desligamento?

Aqui está a última parte do log do console antes de inicializá-lo novamente:

4/7/15 1:54:01.035 PM ReportCrash[18379]: Saved crash report for xcssecurity[18377] version 6743 to /Library/Logs/DiagnosticReports/xcssecurity_2015-04-07-135401_Nexts-Mac-mini.crash
4/7/15 1:54:01.059 PM ReportCrash[18379]: Saved crash report for xcssecurity[18375] version 6743 to /Library/Logs/DiagnosticReports/xcssecurity_2015-04-07-135401-1_Nexts-Mac-mini.crash
4/7/15 1:54:01.255 PM ReportCrash[18379]: Saved crash report for xcssecurity[18376] version 6743 to /Library/Logs/DiagnosticReports/xcssecurity_2015-04-07-135401-2_Nexts-Mac-mini.crash
4/7/15 2:01:26.504 PM com.apple.backupd-helper[52]: Attempt to use XPC with a MachService that has HideUntilCheckIn set. This will result in unpredictable behavior: com.apple.backupd.status.xpc
4/7/15 2:01:56.785 PM com.apple.backupd[18749]: Starting automatic backup
4/7/15 2:01:57.008 PM com.apple.backupd[18749]: Backing up to /dev/disk8: /Volumes/Next's Time Capsule/Backups.backupdb
4/7/15 2:01:57.483 PM serveradmin[18753]: Connected to the Notify Service
4/7/15 2:01:57.526 PM serveradmin[18755]: Connected to the Notify Service
4/7/15 2:01:57.564 PM serveradmin[18757]: Connected to the Notify Service
4/7/15 2:01:57.602 PM serveradmin[18759]: Connected to the Notify Service
4/7/15 2:01:57.663 PM servermgr_devicemgr[18760]: Connected to the Notify Service
4/7/15 2:01:57.665 PM serveradmin[18761]: Connected to the Notify Service
4/7/15 2:01:57.688 PM servermgr_devicemgr[18760]: getStateWithRequest:
———————+———————
state : STOPPED
———————+———————
4/7/15 2:01:57.755 PM serveradmin[18768]: Connected to the Notify Service
4/7/15 2:01:57.793 PM serveradmin[18770]: Connected to the Notify Service
4/7/15 2:01:57.833 PM serveradmin[18772]: Connected to the Notify Service
4/7/15 2:01:57.892 PM servermgr_info[18773]: Connected to the Notify Service
4/7/15 2:01:57.913 PM serveradmin[18774]: Connected to the Notify Service
4/7/15 2:01:57.974 PM serveradmin[18777]: Connected to the Notify Service
4/7/15 2:01:58.027 PM serveradmin[18780]: Connected to the Notify Service
4/7/15 2:01:58.066 PM serveradmin[18782]: Connected to the Notify Service
4/7/15 2:01:58.067 PM serveradmin[18782]: getConnectionForModule: module servermgr_postgres not found, returning nil
4/7/15 2:01:58.067 PM serveradmin[18782]: sendRequest: cannot contact servermgr_postgres
4/7/15 2:01:58.085 PM serveradmin[18783]: Connected to the Notify Service
4/7/15 2:01:58.855 PM serveradmin[18790]: Connected to the Notify Service
4/7/15 2:01:58.913 PM serveradmin[18792]: Connected to the Notify Service
4/7/15 2:01:58.956 PM serveradmin[18794]: Connected to the Notify Service
4/7/15 2:01:59.016 PM serveradmin[18796]: Connected to the Notify Service
4/7/15 2:01:59.626 PM servermgr_swupdate[18797]: servermgr_swupdate[WRN]: Missing or invalid language for product items request.  Using default "en".
4/7/15 2:01:59.647 PM serveradmin[18798]: Connected to the Notify Service
4/7/15 2:01:59.682 PM servermgr_timemachine[18799]: Connected to the Notify Service
4/7/15 2:01:59.709 PM serveradmin[18800]: Connected to the Notify Service
4/7/15 2:01:59.991 PM serveradmin[18802]: Connected to the Notify Service
4/7/15 2:02:00.175 PM certadmin[18807]: BundleManager(non-plugin calling servermgr_certs): doCommand waiting for reply from servermgr_certs
4/7/15 2:02:00.174 PM certadmin[18807]: Connected to the Notify Service
4/7/15 2:02:00.217 PM certadmin[18807]: BundleManager(non-plugin calling servermgr_certs): got a reply = {
    exportDirectoryPath = "/etc/certificates";
}
4/7/15 2:02:00.217 PM certadmin[18807]: BundleManager(non-plugin calling servermgr_certs): doCommand finished reply = {
    exportDirectoryPath = "/etc/certificates";
}
4/7/15 2:02:00.301 PM serveradmin[18812]: Connected to the Notify Service
4/7/15 2:02:00.445 PM collabd[18819]: objc[18819]: Class CSArchive is implemented in both /Applications/Server.app/Contents/ServerRoot/System/Library/PrivateFrameworks/CSService.framework/Versions/A/CSService and /Applications/Server.app/Contents/ServerRoot/usr/sbin/collabd. One of the two will be used. Which one is undefined.
4/7/15 2:02:02.210 PM collabd[18819]: [main.m:341 7d465300 +3ms] HTTP server listening at localhost:4444
4/7/15 2:02:02.210 PM collabd[18819]: [main.m:342 7d465300 +0ms] HTTPS server listening at localhost:4443
4/7/15 2:02:02.211 PM collabd[18819]: [main.m:366 7d465300 +0ms] Configured to exit after about 360 seconds idle
4/7/15 2:02:02.350 PM serveradmin[18854]: Connected to the Notify Service
4/7/15 2:02:05.053 PM serveradmin[18903]: Connected to the Notify Service
4/7/15 2:02:05.070 PM serveradmin[18904]: Connected to the Notify Service
4/7/15 2:02:05.073 PM servermgr_accounts[18754]: Connected to the Notify Service
4/7/15 2:02:05.089 PM serveradmin[18905]: Connected to the Notify Service
4/7/15 2:02:05.113 PM serveradmin[18906]: Connected to the Notify Service
4/7/15 2:02:05.130 PM serveradmin[18907]: Connected to the Notify Service
4/7/15 2:02:05.133 PM servermgr_afp[18756]: Connected to the Notify Service
4/7/15 2:02:05.150 PM serveradmin[18908]: Connected to the Notify Service
4/7/15 2:02:05.172 PM serveradmin[18909]: Connected to the Notify Service
4/7/15 2:02:05.189 PM serveradmin[18910]: Connected to the Notify Service
4/7/15 2:02:05.201 PM servermgr_caching[18758]: Connected to the Notify Service
4/7/15 2:02:05.218 PM serveradmin[18911]: Connected to the Notify Service
4/7/15 2:02:05.244 PM serveradmin[18912]: Connected to the Notify Service
4/7/15 2:02:05.264 PM serveradmin[18913]: Connected to the Notify Service
4/7/15 2:02:05.289 PM serveradmin[18914]: Connected to the Notify Service
4/7/15 2:02:05.312 PM serveradmin[18915]: Connected to the Notify Service
4/7/15 2:02:05.370 PM serveradmin[18920]: Connected to the Notify Service
4/7/15 2:02:05.373 PM servermgr_dirserv[18763]: Connected to the Notify Service
4/7/15 2:02:05.389 PM serveradmin[18921]: Connected to the Notify Service
4/7/15 2:02:05.411 PM serveradmin[18922]: Connected to the Notify Service
4/7/15 2:02:05.428 PM serveradmin[18923]: Connected to the Notify Service
4/7/15 2:02:05.431 PM servermgr_dns[18769]: Connected to the Notify Service
4/7/15 2:02:05.447 PM serveradmin[18924]: Connected to the Notify Service
4/7/15 2:02:05.469 PM serveradmin[18925]: Connected to the Notify Service
4/7/15 2:02:05.486 PM serveradmin[18926]: Connected to the Notify Service
4/7/15 2:02:05.499 PM servermgr_ftp[18771]: Connected to the Notify Service
4/7/15 2:02:05.515 PM serveradmin[18927]: Connected to the Notify Service
4/7/15 2:02:05.540 PM serveradmin[18928]: Connected to the Notify Service
4/7/15 2:02:05.561 PM serveradmin[18929]: Connected to the Notify Service
4/7/15 2:02:05.615 PM serveradmin[18930]: Connected to the Notify Service
4/7/15 2:02:05.661 PM serveradmin[18931]: Connected to the Notify Service
4/7/15 2:02:05.697 PM serveradmin[18933]: Connected to the Notify Service
4/7/15 2:02:05.709 PM servermgr_jabber[18775]: Connected to the Notify Service
4/7/15 2:02:05.726 PM serveradmin[18935]: Connected to the Notify Service
4/7/15 2:02:05.757 PM serveradmin[18937]: Connected to the Notify Service
4/7/15 2:02:05.786 PM serveradmin[18938]: Connected to the Notify Service
4/7/15 2:02:06.914 PM servermgr_network[18779]: Connected to the Notify Service
4/7/15 2:02:06.933 PM serveradmin[18939]: Connected to the Notify Service
4/7/15 2:02:08.069 PM serveradmin[18940]: Connected to the Notify Service
4/7/15 2:02:08.085 PM serveradmin[18941]: Connected to the Notify Service
4/7/15 2:02:08.095 PM servermgr_nfs[18781]: Connected to the Notify Service
4/7/15 2:02:08.112 PM serveradmin[18943]: Connected to the Notify Service
4/7/15 2:02:08.142 PM serveradmin[18945]: Connected to the Notify Service
4/7/15 2:02:08.143 PM serveradmin[18945]: getConnectionForModule: module servermgr_postgres not found, returning nil
4/7/15 2:02:08.143 PM serveradmin[18945]: sendRequest: cannot contact servermgr_postgres
4/7/15 2:02:08.159 PM serveradmin[18946]: Connected to the Notify Service
4/7/15 2:02:08.160 PM serveradmin[18946]: getConnectionForModule: module servermgr_postgres not found, returning nil
4/7/15 2:02:08.161 PM serveradmin[18946]: sendRequest: cannot contact servermgr_postgres
4/7/15 2:02:08.178 PM serveradmin[18947]: Connected to the Notify Service
4/7/15 2:02:08.180 PM serveradmin[18947]: getConnectionForModule: module servermgr_postgres not found, returning nil
4/7/15 2:02:08.180 PM serveradmin[18947]: sendRequest: cannot contact servermgr_postgres
4/7/15 2:02:08.201 PM serveradmin[18948]: Connected to the Notify Service
4/7/15 2:02:08.267 PM serveradmin[18951]: Connected to the Notify Service
4/7/15 2:02:08.270 PM servermgr_radius[18784]: Connected to the Notify Service
4/7/15 2:02:08.286 PM serveradmin[18952]: Connected to the Notify Service
4/7/15 2:02:08.308 PM serveradmin[18953]: Connected to the Notify Service
4/7/15 2:02:08.326 PM serveradmin[18954]: Connected to the Notify Service
4/7/15 2:02:08.329 PM servermgr_san[18791]: Connected to the Notify Service
4/7/15 2:02:08.346 PM serveradmin[18955]: Connected to the Notify Service
4/7/15 2:02:08.367 PM serveradmin[18956]: Connected to the Notify Service
4/7/15 2:02:08.387 PM serveradmin[18957]: Connected to the Notify Service
4/7/15 2:02:08.389 PM servermgr_sharing[18793]: Connected to the Notify Service
4/7/15 2:02:08.407 PM serveradmin[18958]: Connected to the Notify Service
4/7/15 2:02:08.428 PM serveradmin[18959]: Connected to the Notify Service
4/7/15 2:02:08.446 PM serveradmin[18961]: Connected to the Notify Service
4/7/15 2:02:08.449 PM servermgr_smb[18795]: Connected to the Notify Service
4/7/15 2:02:08.465 PM serveradmin[18962]: Connected to the Notify Service
4/7/15 2:02:08.488 PM serveradmin[18963]: Connected to the Notify Service
4/7/15 2:02:08.491 PM servermgr_swupdate[18797]: servermgr_swupdate[WRN]: Missing or invalid language for product items request.  Using default "en".
4/7/15 2:02:08.507 PM serveradmin[18964]: Connected to the Notify Service
4/7/15 2:02:08.541 PM servermgr_swupdate[18797]: Connected to the Notify Service
4/7/15 2:02:08.558 PM serveradmin[18965]: Connected to the Notify Service
4/7/15 2:02:08.585 PM serveradmin[18966]: Connected to the Notify Service
4/7/15 2:02:08.610 PM serveradmin[18967]: Connected to the Notify Service
4/7/15 2:02:08.638 PM serveradmin[18968]: Connected to the Notify Service
4/7/15 2:02:08.669 PM serveradmin[18969]: Connected to the Notify Service
4/7/15 2:02:08.689 PM serveradmin[18970]: Connected to the Notify Service
4/7/15 2:02:08.692 PM servermgr_vpn[18801]: Connected to the Notify Service
4/7/15 2:02:08.711 PM serveradmin[18971]: Connected to the Notify Service
4/7/15 2:02:08.733 PM serveradmin[18972]: Connected to the Notify Service
4/7/15 2:02:08.850 PM serveradmin[18974]: Connected to the Notify Service
4/7/15 2:02:08.852 PM servermgr_web[18762]: Connected to the Notify Service
4/7/15 2:02:08.871 PM serveradmin[18975]: Connected to the Notify Service
4/7/15 2:02:08.894 PM serveradmin[18976]: Connected to the Notify Service
4/7/15 2:02:09.001 PM serveradmin[18979]: Connected to the Notify Service
4/7/15 2:02:09.003 PM servermgr_wiki[18813]: Connected to the Notify Service
4/7/15 2:02:09.021 PM serveradmin[18980]: Connected to the Notify Service
4/7/15 2:02:09.044 PM serveradmin[18981]: Connected to the Notify Service
4/7/15 2:02:11.216 PM serveradmin[18987]: Connected to the Notify Service
4/7/15 2:02:12.021 PM servermgr_xcode[18855]: Connected to the Notify Service
4/7/15 2:02:12.040 PM serveradmin[18990]: Connected to the Notify Service
4/7/15 2:02:13.923 PM com.apple.backupd[18749]: Will copy (141.7 MB) from Macintosh HD
4/7/15 2:02:13.924 PM com.apple.backupd[18749]: Found 171 files (141.7 MB) needing backup
4/7/15 2:02:13.954 PM com.apple.backupd[18749]: 876.3 MB required (including padding), 314.35 GB available
4/7/15 2:02:19.192 PM com.apple.backupd[18749]: Copied 181 items (141.7 MB) from volume Macintosh HD. Linked 939.
4/7/15 2:02:20.402 PM com.apple.backupd[18749]: Created new backup: 2015-04-07-140220
4/7/15 2:02:21.317 PM com.apple.xpc.launchd[1]: (com.apple.imfoundation.IMRemoteURLConnectionAgent) The _DirtyJetsamMemoryLimit key is not available on this platform.
4/7/15 2:02:21.000 PM kernel[0]: hfs: mounted Boot OS X on device disk5s6
4/7/15 2:02:21.000 PM kernel[0]: hfs: unmount initiated on Boot OS X on device disk5s6
4/7/15 2:02:21.766 PM AppleFileServer[884]: GetAttrListStandardVolumeInfo:  getattrlist failed with errno: 2!
4/7/15 2:02:23.621 PM com.apple.backupd[18749]: Starting post-backup thinning
4/7/15 2:02:24.026 PM com.apple.backupd[18749]: Deleted /Volumes/Next's Time Capsule/Backups.backupdb/Next’s Mac mini/2015-04-06-130722 (100.7 MB)
4/7/15 2:02:24.026 PM com.apple.backupd[18749]: Post-backup thinning complete: 1 expired backups removed
4/7/15 2:02:24.118 PM com.apple.backupd[18749]: Backup completed successfully.
4/7/15 2:04:25.583 PM SystemUIServer[824]: Attempt to use XPC with a MachService that has HideUntilCheckIn set. This will result in unpredictable behavior: com.apple.backupd.status.xpc
4/7/15 2:04:25.583 PM SystemUIServer[418]: Attempt to use XPC with a MachService that has HideUntilCheckIn set. This will result in unpredictable behavior: com.apple.backupd.status.xpc
4/7/15 2:07:12.439 PM servermgr_accounts[18754]: idle exit
4/7/15 2:07:12.544 PM servermgr_afp[18756]: idle exit
4/7/15 2:07:12.545 PM servermgr_timemachine[18799]: Dispatcher: servermgr_afp plugin disconnected
4/7/15 2:07:12.571 PM servermgr_caching[18758]: idle exit
4/7/15 2:07:12.637 PM servermgr_devicemgr[18760]: idle exit
4/7/15 2:07:12.670 PM servermgr_dirserv[18763]: idle exit
4/7/15 2:07:12.769 PM servermgr_dns[18769]: idle exit
4/7/15 2:07:12.801 PM servermgr_ftp[18771]: idle exit
4/7/15 2:07:12.834 PM servermgr_info[18773]: idle exit
4/7/15 2:07:12.934 PM servermgr_jabber[18775]: idle exit
4/7/15 2:07:13.032 PM servermgr_nfs[18781]: idle exit
4/7/15 2:07:13.032 PM servermgr_radius[18784]: idle exit
4/7/15 2:07:13.140 PM servermgr_network[18779]: idle exit
4/7/15 2:07:13.853 PM servermgr_san[18791]: idle exit
4/7/15 2:07:13.919 PM servermgr_sharing[18793]: idle exit
4/7/15 2:07:13.920 PM servermgr_timemachine[18799]: Dispatcher: servermgr_sharing plugin disconnected
4/7/15 2:07:13.953 PM servermgr_smb[18795]: idle exit
4/7/15 2:07:14.039 PM servermgr_swupdate[18797]: idle exit
4/7/15 2:07:14.648 PM servermgr_timemachine[18799]: idle exit
4/7/15 2:07:14.952 PM servermgr_vpn[18801]: idle exit
4/7/15 2:07:15.202 PM servermgr_certs[18808]: idle exit
4/7/15 2:07:15.365 PM servermgr_wiki[18813]: idle exit
4/7/15 2:07:17.382 PM servermgr_xcode[18855]: idle exit
4/7/15 2:08:12.646 PM servermgr_web[18762]: idle exit
4/7/15 2:17:54.104 PM AppleFileServer[884]: Logged out 0x7fece500c000
4/7/15 2:23:14.994 PM com.apple.xpc.launchd[1]: (com.apple.imfoundation.IMRemoteURLConnectionAgent) The _DirtyJetsamMemoryLimit key is not available on this platform.
4/7/15 2:23:15.059 PM com.apple.iCloudHelper[20168]: objc[20168]: Class FALogging is implemented in both /System/Library/PrivateFrameworks/FamilyCircle.framework/Versions/A/FamilyCircle and /System/Library/PrivateFrameworks/FamilyNotification.framework/Versions/A/FamilyNotification. One of the two will be used. Which one is undefined.
4/7/15 2:23:15.068 PM com.apple.xpc.launchd[1]: (com.apple.imfoundation.IMRemoteURLConnectionAgent) The _DirtyJetsamMemoryLimit key is not available on this platform.
4/7/15 2:24:00.202 PM com.apple.xpc.launchd[1]: (com.apple.ReportCrash.Root[20194]) Endpoint has been activated through legacy launch(3) APIs. Please switch to XPC or bootstrap_check_in(): com.apple.ReportCrash.DirectoryService
4/7/15 2:24:01.693 PM ReportCrash[20194]: Saved crash report for xcssecurity[20191] version 6743 to /Library/Logs/DiagnosticReports/xcssecurity_2015-04-07-142401_Nexts-Mac-mini.crash
4/7/15 2:24:01.709 PM ReportCrash[20194]: Saved crash report for xcssecurity[20190] version 6743 to /Library/Logs/DiagnosticReports/xcssecurity_2015-04-07-142401-1_Nexts-Mac-mini.crash
4/7/15 2:38:20.963 PM awdd[55]: Saved awd report for awdd version awd-osx to /Library/Logs/DiagnosticReports/awdd_2015-04-07-143820_Nexts-Mac-mini.awd
4/7/15 2:38:21.080 PM awdd[55]: Diagnostics Report
4/8/15 11:14:44.000 AM bootlog[0]: BOOT_TIME 1428516884 0
4/8/15 11:15:09.000 AM syslogd[22]: Configuration Notice:
ASL Module "com.apple.AccountPolicyHelper" claims selected messages.
Those messages may not appear in standard system log files or in the ASL database.