KVM Host Faulty Disk
Eventually a harddrive will fail. Harddrives have moving parts and they will wear out. Having installed and configured smartmontools an email like the following will show up in your inbox.
From root@kvm02.kallenberg.dk Wed Oct 18 23:14:11 2017 Subject: SMART error (SelfTest) detected on host: kvm02 To: <root@kvm02.kallenberg.dk> X-Mailer: mail (GNU Mailutils 3.1.1) This message was generated by the smartd daemon running on: host name: kvm02 DNS domain: kallenberg.dk The following warning/error was logged by the smartd daemon: Device: /dev/sdd, Self-Test Log error count increased from 0 to 1 Device info: ST2000DM001-1CH164, S/N:Z2F0RD5S, WWN:5-000c50-050214cd9, FW:CC26, 2.00 TB For details see host's SYSLOG. You can also use the smartctl utility for further investigation. Another message will be sent in 24 hours if the problem persists.
Just to be sure, run a thorough test yourself.
# smartctl -t long /dev/sdd smartctl 6.6 2016-05-31 r4324 [x86_64-linux-4.9.0-3-amd64] (local build) Copyright (C) 2002-16, Bruce Allen, Christian Franke, www.smartmontools.org === START OF OFFLINE IMMEDIATE AND SELF-TEST SECTION === Sending command: "Execute SMART Extended self-test routine immediately in off-line mode". Drive command "Execute SMART Extended self-test routine immediately in off-line mode" successful. Testing has begun. Please wait 230 minutes for test to complete. Test will complete after Fri Oct 20 03:45:07 2017 Use smartctl -X to abort test.
Once the test has completed, take a look at the smartctl report.
smartctl -a /dev/sdd
This will show a long report, where the selftest is the interesting part.
SMART Self-test log structure revision number 1 Num Test_Description Status Remaining LifeTime(hours) LBA_of_first_error # 1 Extended offline Completed: read failure 90% 8057 2144 # 2 Extended offline Completed: read failure 90% 8053 2144 # 3 Extended offline Completed: read failure 90% 8051 2144 # 4 Extended offline Completed without error 00% 7986 - # 5 Extended offline Completed without error 00% 7828 - # 6 Extended offline Completed without error 00% 7818 -