dmesg

顯示Linux系統啟動信息

補充說明

dmesg命令 被用于檢查和控制內核的環形緩沖區。kernel會將開機信息存儲在ring?buffer中。您若是開機時來不及查看信息，可利用dmesg來查看。開機信息保存在/var/log/dmesg文件里。

語法

dmesg(選項)

選項

-c：顯示信息后，清除ring buffer中的內容；
-s<緩沖區大小>：預設置為8196，剛好等于ring buffer的大小；
-n：設置記錄信息的層級。

實例

[root@localhost ~]# dmesg | head
Linux version 2.6.18-348.6.1.el5 (mockbuild@builder17.centos.org) (gcc version 4.1.2 20080704 (Red Hat 4.1.2-54)) #1 SMP Tue May 21 15:34:22 EDT 2013
BIOS-provided physical RAM map:
 BIOS-e820: 0000000000010000 - 000000000009f400 (usable)
 BIOS-e820: 000000000009f400 - 00000000000a0000 (reserved)
 BIOS-e820: 00000000000f0000 - 0000000000100000 (reserved)
 BIOS-e820: 0000000000100000 - 000000007f590000 (usable)
 BIOS-e820: 000000007f590000 - 000000007f5e3000 (ACPI NVS)
 BIOS-e820: 000000007f5e3000 - 000000007f5f0000 (ACPI data)
 BIOS-e820: 000000007f5f0000 - 000000007f600000 (reserved)
 BIOS-e820: 00000000e0000000 - 00000000e8000000 (reserved)

查看硬盤基礎信息

dmesg | grep sda

[    2.442555] sd 0:0:0:0: [sda] 488281250 512-byte logical blocks: (250 GB/232 GiB)
[    2.442590] sd 0:0:0:0: [sda] Write Protect is off
[    2.442592] sd 0:0:0:0: [sda] Mode Sense: 00 3a 00 00
[    2.442607] sd 0:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA
[    2.447533]  sda: sda1
[    2.448503] sd 0:0:0:0: [sda] Attached SCSI disk