我们有 rhel 7.2 服务器
从dmesg -T我们只看到当前日期 -Mon Jan 11
而不是历史日期jan 10，或者小于jan 10
dmesg -T
[Mon Jan 11 12:02:53 2021] Initializing cgroup subsys cpuset
[Mon Jan 11 12:02:53 2021] Initializing cgroup subsys cpu
[Mon Jan 11 12:02:53 2021] Initializing cgroup subsys cpuacct
[Mon Jan 11 12:02:53 2021] Disabled fast string operations
[Mon Jan 11 12:02:53 2021] e820: BIOS-provided physical RAM map:
[Mon Jan 11 12:02:53 2021] BIOS-e820: [mem 0x0000000000000000-0x000000000009ebff] usable
[Mon Jan 11 12:02:53 2021] BIOS-e820: [mem 0x000000000009ec00-0x000000000009ffff] reserved
[Mon Jan 11 12:02:53 2021] BIOS-e820: [mem 0x00000000000dc000-0x00000000000fffff] reserved
[Mon Jan 11 12:02:53 2021] BIOS-e820: [mem 0x0000000000100000-0x00000000bfecffff] usable
[Mon Jan 11 12:02:53 2021] BIOS-e820: [mem 0x00000000bfed0000-0x00000000bfefefff] ACPI data
[Mon Jan 11 12:02:53 2021] BIOS-e820: [mem 0x00000000bfeff000-0x00000000bfefffff] ACPI NVS
[Mon Jan 11 12:02:53 2021] BIOS-e820: [mem 0x00000000bff00000-0x00000000bfffffff] usable
[Mon Jan 11 12:02:53 2021] BIOS-e820: [mem 0x00000000f0000000-0x00000000f7ffffff] reserved
[Mon Jan 11 12:02:53 2021] BIOS-e820: [mem 0x00000000fec00000-0x00000000fec0ffff] reserved
[Mon Jan 11 12:02:53 2021] BIOS-e820: [mem 0x00000000fee00000-0x00000000fee00fff] reserved
[Mon Jan 11 12:02:53 2021] BIOS-e820: [mem 0x00000000fffe0000-0x00000000ffffffff] reserved
[Mon Jan 11 12:02:53 2021] BIOS-e820: [mem 0x0000000100000000-0x0000000427ffffff] usable
[Mon Jan 11 12:02:53 2021] NX (Execute Disable) protection: active
[Mon Jan 11 12:02:53 2021] SMBIOS 2.7 present.
[Mon Jan 11 12:02:53 2021] DMI: VMware, Inc. VMware Virtual Platform/440BX Desktop Reference Platform, BIOS 6.00 12/12/2018
[Mon Jan 11 12:02:53 2021] Hypervisor detected: VMware
[Mon Jan 11 12:02:53 2021] vmware: TSC freq read from hypervisor : 2397.223 MHz
[Mon Jan 11 12:02:53 2021] vmware: Host bus clock speed read from hypervisor : 66000000 Hz
[Mon Jan 11 12:02:53 2021] vmware: using sched offset of 8561845015 ns
[Mon Jan 11 12:02:53 2021] e820: update [mem 0x00000000-0x00000fff] usable ==> reserved
[Mon Jan 11 12:02:53 2021] e820: remove [mem 0x000a0000-0x000fffff] usable
[Mon Jan 11 12:02:53 2021] e820: last_pfn = 0x428000 max_arch_pfn = 0x400000000
[Mon Jan 11 12:02:53 2021] MTRR default type: uncachable
[Mon Jan 11 12:02:53 2021] MTRR fixed ranges enabled:
[Mon Jan 11 12:02:53 2021] 00000-9FFFF write-back
[Mon Jan 11 12:02:53 2021] A0000-BFFFF uncachable
[Mon Jan 11 12:02:53 2021] C0000-CBFFF write-protect
[Mon Jan 11 12:02:53 2021] CC000-EFFFF uncachable
[Mon Jan 11 12:02:53 2021] F0000-FFFFF write-protect
[Mon Jan 11 12:02:53 2021] MTRR variable ranges enabled:
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为了扩展 dmesg 详细信息并查看 dmesg 信息，我们需要做哪些 dmesg 设置或 dmesg 更改？