This is the conlog replica. It appears to have started around 5:00 PM and repeated each hour after. I had to restart the database replication, it appears that the database has been crashing in response. It may not be a coincidence that the search for frequently changing channels also runs every hour, so I have disabled it. cdsadmin@h1conlog3:/var/log$ grep error syslog Feb 4 17:04:08 h1conlog3 kernel: [2335398.323116] res 51/40:0a:16:e8:88/00:00:00:00:00/0b Emask 0x9 (media error) Feb 4 17:04:08 h1conlog3 kernel: [2335398.323407] ata3.00: error: { UNC } Feb 4 17:04:08 h1conlog3 kernel: [2335398.344358] Add. Sense: Unrecovered read error - auto reallocate failed Feb 4 17:04:08 h1conlog3 kernel: [2335398.344367] end_request: I/O error, dev sda, sector 193521686 Feb 4 17:04:11 h1conlog3 kernel: [2335401.397976] res 51/40:02:16:e8:88/00:00:00:00:00/0b Emask 0x9 (media error) Feb 4 17:04:11 h1conlog3 kernel: [2335401.398264] ata3.00: error: { UNC } Feb 4 17:04:11 h1conlog3 kernel: [2335401.420344] Add. Sense: Unrecovered read error - auto reallocate failed Feb 4 17:04:11 h1conlog3 kernel: [2335401.420352] end_request: I/O error, dev sda, sector 193521686 ...