some errors i've found:
Apr 24 19:32:55 Toshokan kernel: mce: [Hardware Error]: Machine check events logged
Apr 24 19:32:55 Toshokan kernel: mce: [Hardware Error]: CPU 3: Machine Check: 0 Bank 5: bea0000000000108
Apr 24 19:32:55 Toshokan kernel: mce: [Hardware Error]: TSC 0 ADDR 1ffff816bd1ee MISC d012000100000000 SYND 4d000000 IPID 500b000000000
Apr 24 19:32:55 Toshokan kernel: mce: [Hardware Error]: PROCESSOR 2:800f11 TIME 1650846747 SOCKET 0 APIC 8 microcode 8001138
Apr 24 19:32:55 Toshokan kernel: #4 #5 #6
Apr 24 19:32:55 Toshokan kernel: mce: [Hardware Error]: Machine check events logged
Apr 24 19:32:55 Toshokan kernel: #7
Apr 24 19:32:55 Toshokan kernel: mce: [Hardware Error]: CPU 6: Machine Check: 0 Bank 5: bea0000000000108
Apr 24 19:32:55 Toshokan kernel: mce: [Hardware Error]: TSC 0 ADDR 1ffff813c3d3e MISC d012000100000000 SYND 4d000000 IPID 500b000000000
Apr 24 19:32:55 Toshokan kernel: mce: [Hardware Error]: PROCESSOR 2:800f11 TIME 1650846747 SOCKET 0 APIC 1 microcode 8001138
Apr 24 19:33:05 Toshokan ntpd[1954]: kernel reports TIME_ERROR: 0x41: Clock Unsynchronized
Apr 24 19:35:27 Toshokan nginx: 2022/04/24 19:35:27 [error] 10330#10330: *125 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream, client: 127.0.0.1, server: , request: "GET /admin/api.php?version HTTP/1.1", upstream: "fastcgi://unix:/var/run/php5-fpm.sock:", host: "127.0.0.1"
Apr 24 19:35:27 Toshokan nginx: 2022/04/24 19:35:27 [error] 10330#10330: *127 FastCGI sent in stderr: "Primary script unknown" while reading response header from upstream, client: 127.0.0.1, server: , request: "GET /admin/api.php?version HTTP/1.1", upstream: "fastcgi://unix:/var/run/php5-fpm.sock:", host: "localhost"
2022-04-25 00:34:56.971+0000: 8859: error : virNetSocketReadWire:1826 : End of file while reading data: Input/output error
2022-04-25 00:35:00.403+0000: 8859: error : virNetSocketReadWire:1826 : End of file while reading data: Input/output error
2022-04-25 00:35:03.911+0000: 8859: error : virNetSocketReadWire:1826 : End of file while reading data: Input/output error