7 Kmandi dmesg għal Soluzzjoni ta' Problemi u Ġbir ta' Informazzjoni ta' Sistemi Linux
Il-kmand 'dmesg' juri l-messaġġi mill-buffer taċ-ċirku tal-kernel. Sistema tgħaddi minn diversi runlevel minn fejn nistgħu niksbu ħafna informazzjoni bħall-arkitettura tas-sistema, CPU, apparat imwaħħal, RAM eċċ. Meta l-kompjuter jibda, kernel (qalba ta’ sistema operattiva) jitgħabba fil-memorja. Matul dak il-perjodu numru ta 'messaġġi qed jintwerew fejn nistgħu naraw apparati tal-ħardwer misjuba mill-kernel.
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Il-messaġġi huma importanti ħafna f'termini ta 'skop ta' dijanjosi f'każ ta 'ħsara fl-apparat. Meta nikkonnettjaw jew skonnettjaw apparat tal-ħardwer fuq is-sistema, bl-għajnuna tal-kmand dmesg insiru nafu informazzjoni skoperta jew skonnettjata fuq il-fly. Il-kmand dmesg huwa disponibbli fuq il-biċċa l-kbira tas-Sistema Operattiva bbażata fuq Linux u Unix.
Ejja nitfgħu ftit dawl fuq l-aktar għodda famuża msejħa kmand 'dmesg' bl-eżempji prattiċi tagħhom kif diskuss hawn taħt. Is-sintassi eżatta ta' dmesg kif ġej.
# dmseg [options...]
1. Elenka s-Sewwieqa kollha mgħobbija fil-kernel
Nistgħu nużaw għodod għall-manipulazzjoni tat-test jiġifieri 'aktar', 'denb', 'inqas' jew 'grep 'b'kmand dmesg. Peress li l-output tad-dmesg log ma joqgħodx fuq paġna waħda, l-użu ta 'dmesg b'pipe kmand aktar jew inqas se juri zkuk f'paġna waħda.
dmesg | more dmesg | less
[ 0.000000] Initializing cgroup subsys cpuset [ 0.000000] Initializing cgroup subsys cpu [ 0.000000] Initializing cgroup subsys cpuacct [ 0.000000] Linux version 3.11.0-13-generic ([email ) (gcc version 4.8.1 (Ubuntu/Linaro 4.8.1-10ubuntu8) ) #20-Ubuntu SMP Wed Oct 23 17:26:33 UTC 2013 (Ubuntu 3.11.0-13.20-generic 3.11.6) [ 0.000000] KERNEL supported cpus: [ 0.000000] Intel GenuineIntel [ 0.000000] AMD AuthenticAMD [ 0.000000] NSC Geode by NSC [ 0.000000] Cyrix CyrixInstead [ 0.000000] Centaur CentaurHauls [ 0.000000] Transmeta GenuineTMx86 [ 0.000000] Transmeta TransmetaCPU [ 0.000000] UMC UMC UMC UMC [ 0.000000] e820: BIOS-provided physical RAM map: [ 0.000000] BIOS-e820: [mem 0x0000000000000000-0x000000000009fbff] usable [ 0.000000] BIOS-e820: [mem 0x00000000000f0000-0x00000000000fffff] reserved [ 0.000000] BIOS-e820: [mem 0x0000000000100000-0x000000007dc08bff] usable [ 0.000000] BIOS-e820: [mem 0x000000007dc08c00-0x000000007dc5cbff] ACPI NVS [ 0.000000] BIOS-e820: [mem 0x000000007dc5cc00-0x000000007dc5ebff] ACPI data [ 0.000000] BIOS-e820: [mem 0x000000007dc5ec00-0x000000007fffffff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000e0000000-0x00000000efffffff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000fec00000-0x00000000fed003ff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000fed20000-0x00000000fed9ffff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000fee00000-0x00000000feefffff] reserved [ 0.000000] BIOS-e820: [mem 0x00000000ffb00000-0x00000000ffffffff] reserved [ 0.000000] NX (Execute Disable) protection: active .....
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2. Elenka l-Apparati Individwati kollha
Biex tiskopri liema hard disks ġew skoperti mill-qalba, tista 'tfittex il-kelma prinċipali sda flimkien ma' grep bħal muri hawn taħt.
dmesg | grep sda [ 1.280971] sd 2:0:0:0: [sda] 488281250 512-byte logical blocks: (250 GB/232 GiB) [ 1.281014] sd 2:0:0:0: [sda] Write Protect is off [ 1.281016] sd 2:0:0:0: [sda] Mode Sense: 00 3a 00 00 [ 1.281039] sd 2:0:0:0: [sda] Write cache: enabled, read cache: enabled, doesn't support DPO or FUA [ 1.359585] sda: sda1 sda2 < sda5 sda6 sda7 sda8 > [ 1.360052] sd 2:0:0:0: [sda] Attached SCSI disk [ 2.347887] EXT4-fs (sda1): mounted filesystem with ordered data mode. Opts: (null) [ 22.928440] Adding 3905532k swap on /dev/sda6. Priority:-1 extents:1 across:3905532k FS [ 23.950543] EXT4-fs (sda1): re-mounted. Opts: errors=remount-ro [ 24.134016] EXT4-fs (sda5): mounted filesystem with ordered data mode. Opts: (null) [ 24.330762] EXT4-fs (sda7): mounted filesystem with ordered data mode. Opts: (null) [ 24.561015] EXT4-fs (sda8): mounted filesystem with ordered data mode. Opts: (null)
NOTA: L-ewwel hard drive SATA 'sda', 'sdb' hija t-tieni hard drive SATA u l-bqija. Fittex b''hda' jew 'hdb' fil-każ ta' hard drive IDE.
3. Stampa biss l-Ewwel 20 Linja ta 'Output
Ir-‘ras’ flimkien ma’ dmesg se juru linji tal-bidu jiġifieri ‘dmesg | head -20’ se tipprintja biss 20 linja mill-punt tat-tluq.
dmesg | head -20 [ 0.000000] Initializing cgroup subsys cpuset [ 0.000000] Initializing cgroup subsys cpu [ 0.000000] Initializing cgroup subsys cpuacct [ 0.000000] Linux version 3.11.0-13-generic ([email ) (gcc version 4.8.1 (Ubuntu/Linaro 4.8.1-10ubuntu8) ) #20-Ubuntu SMP Wed Oct 23 17:26:33 UTC 2013 (Ubuntu 3.11.0-13.20-generic 3.11.6) [ 0.000000] KERNEL supported cpus: [ 0.000000] Intel GenuineIntel [ 0.000000] AMD AuthenticAMD [ 0.000000] NSC Geode by NSC [ 0.000000] Cyrix CyrixInstead [ 0.000000] Centaur CentaurHauls [ 0.000000] Transmeta GenuineTMx86 [ 0.000000] Transmeta TransmetaCPU [ 0.000000] UMC UMC UMC UMC [ 0.000000] e820: BIOS-provided physical RAM map: [ 0.000000] BIOS-e820: [mem 0x0000000000000000-0x000000000009fbff] usable [ 0.000000] BIOS-e820: [mem 0x00000000000f0000-0x00000000000fffff] reserved [ 0.000000] BIOS-e820: [mem 0x0000000000100000-0x000000007dc08bff] usable [ 0.000000] BIOS-e820: [mem 0x000000007dc08c00-0x000000007dc5cbff] ACPI NVS [ 0.000000] BIOS-e820: [mem 0x000000007dc5cc00-0x000000007dc5ebff] ACPI data [ 0.000000] BIOS-e820: [mem 0x000000007dc5ec00-0x000000007fffffff] reserved
4. Stampa biss l-aħħar 20 linja tal-output
Id-‘denb’ flimkien mal-kmand dmesg se jistampaw biss l-aħħar linja 20, dan huwa utli f’każ li ndaħħlu apparat li jista’ jitneħħa.
dmesg | tail -20 parport0: PC-style at 0x378, irq 7 [PCSPP,TRISTATE] ppdev: user-space parallel port driver EXT4-fs (sda1): mounted filesystem with ordered data mode Adding 2097144k swap on /dev/sda2. Priority:-1 extents:1 across:2097144k readahead-disable-service: delaying service auditd ip_tables: (C) 2000-2006 Netfilter Core Team nf_conntrack version 0.5.0 (16384 buckets, 65536 max) NET: Registered protocol family 10 lo: Disabled Privacy Extensions e1000: eth0 NIC Link is Up 1000 Mbps Full Duplex, Flow Control: None Slow work thread pool: Starting up Slow work thread pool: Ready FS-Cache: Loaded CacheFiles: Loaded CacheFiles: Security denies permission to nominate security context: error -95 eth0: no IPv6 routers present type=1305 audit(1398268784.593:18630): audit_enabled=0 old=1 auid=4294967295 ses=4294967295 res=1 readahead-collector: starting delayed service auditd readahead-collector: sorting readahead-collector: finished
5. Fittex Apparat Rilevat jew String Partikolari
Huwa diffiċli li tfittex sekwenza partikolari minħabba t-tul tal-output tad-dmesg. Allura, iffiltra l-linji bi qed ikollhom string bħal usb dma tty u memorja eċċ. L-għażla -i tagħti struzzjonijiet lill-kmand grep biex jinjora l-każ (ittri kbar jew żgħar).
dmesg | grep -i usb dmesg | grep -i dma dmesg | grep -i tty dmesg | grep -i memory
[ 0.000000] Scanning 1 areas for low memory corruption [ 0.000000] initial memory mapped: [mem 0x00000000-0x01ffffff] [ 0.000000] Base memory trampoline at [c009b000] 9b000 size 16384 [ 0.000000] init_memory_mapping: [mem 0x00000000-0x000fffff] [ 0.000000] init_memory_mapping: [mem 0x37800000-0x379fffff] [ 0.000000] init_memory_mapping: [mem 0x34000000-0x377fffff] [ 0.000000] init_memory_mapping: [mem 0x00100000-0x33ffffff] [ 0.000000] init_memory_mapping: [mem 0x37a00000-0x37bfdfff] [ 0.000000] Early memory node ranges [ 0.000000] PM: Registered nosave memory: [mem 0x0009f000-0x000effff] [ 0.000000] PM: Registered nosave memory: [mem 0x000f0000-0x000fffff] [ 0.000000] please try 'cgroup_disable=memory' option if you don't want memory cgroups [ 0.000000] Memory: 2003288K/2059928K available (6352K kernel code, 607K rwdata, 2640K rodata, 880K init, 908K bss, 56640K reserved, 1146920K highmem) [ 0.000000] virtual kernel memory layout: [ 0.004291] Initializing cgroup subsys memory [ 0.004609] Freeing SMP alternatives memory: 28K (c1a3e000 - c1a45000) [ 0.899622] Freeing initrd memory: 23616K (f51d0000 - f68e0000) [ 0.899813] Scanning for low memory corruption every 60 seconds [ 0.946323] agpgart-intel 0000:00:00.0: detected 32768K stolen memory [ 1.360318] Freeing unused kernel memory: 880K (c1962000 - c1a3e000) [ 1.429066] [drm] Memory usable by graphics device = 2048M
6. Ċar dmesg Buffer Logs
Iva, nistgħu naddfu zkuk dmesg jekk meħtieġ bil-kmand hawn taħt. Se tnaddaf ir-reġistri tal-messaġġi tal-buffer taċ-ċirku tad-dmesg sakemm wettaqt il-kmand hawn taħt. Xorta waħda tista 'tara zkuk maħżuna fil-fajls '/var/log/dmesg'. Jekk tikkonnettja kwalunkwe apparat jiġġenera output dmesg.
dmesg -c
7. Monitoraġġ dmesg f'Ħin Real
Xi distro tippermetti kmand 'tail -f /var/log/dmesg' kif ukoll għall-monitoraġġ f'ħin reali tad-dmesg.
watch "dmesg | tail -20"
Konklużjoni: Il-kmand dmesg huwa utli peress li dmesg jirreġistra l-bidliet kollha fis-sistema li saru jew iseħħu f'ħin reali. Bħal dejjem tista' man dmesg biex tikseb aktar informazzjoni.