En esta Oportunidad les Traigo una recopilación de lo q yo concidero son los comandos más, utiles, importantes y usados tanto en Ubuntu como en muchas otras distros linux

• Adduser: Se utiliza para añadir un usuario.

Uso: adduser <nombreusuario>

• Alias (este esta bien explicado en un post anterior)
  

Uso: alias nombrequeledamos=’comando’

• apt-get install nombredelprograma =  instala el paquete.

• apt-get remove nombredelprograma = Borra el paquete. Con la opción –purge borra tambien la configuración del paquete instalado.

• apt-get update = Actualiza la lista de paquetes disponibles para instalar.

• apt-get upgrade  = Instala las nuevas versiones de los diferentes paquetes disponibles.

• cd = Cambia el directorio.

Uso: cd nombredirectorio

Continuar leyendo el resto de comandos:

• chmod: Cambia los permisos de los archivos.

r:lectura w:escritura x:ejecución
+: añade permisos -:quita permisos
u:usuario g:grupo del usuario o:otros
Uso: chmod permisos nombrearchivo

• chown: Cambia el propietario de un archivo.

Uso: chown <nombrepropietario> <nombrearchivo>

• cp:Copia archivos en el directorio indicado.

Uso: cp archivoorigen archivodestino

• deluser: Elimina una cuenta de usuario

Uso: deluser <nombreusuario>

• exit: Cierra las ventanas o las conexiones remotas establecidas

• fsck: Sirve para chequear si hay errores en nuestro disco duro.

Uso: fsck -t <fs_typo> <dispositivo>

• ftp: Protocolo de Transferencia de Archivos, permite transferir archivos de y para computadores remotos.

Uso: ftp <maquina_remota>

• grep: Su funcionalidad es la de escribir en salida estándar aquellas líneas que concuerden con un patrón. Busca patrones en archivos.

grep: grep <patronabuscar> <nombrearchivos>

• ifconfig: Obtener información de la configuración de red

• kill: Termina un proceso

Uso: kill numeroPID

• ls:Lista los archivos y directorios dentro del directorio de trabajo.

• make: Crea ejecutables a partir de los archivos fuente.

• man: muestra el manual de un programa o comando si este esta disponible

Uso: man <nombredelcomando>

• mkdir: Crea un nuevo directorio.

Uso: mkdir nombredirectorio

• mount: Monta una unidad.

Uso: mount -t< sistema_de_archivo> <dispositivo> <nombredirectorio>

• mv: Este comando sirve para renombrar un archivo.

Uso: mv <nombrearchivo> <nuevonombrearchivo>

• netstat:Muestra las conexiones y puertos abiertos por los que se establecen las comunicaciones.

• poweroff: Apaga el ordenador.

• ps: Muestra información acerca de los procesos activos.

• rlogin: Conecta un host local con un host remoto.

Uso: rlogin <maquina_remota>

• rm: Remueve o elimina un archivo.

Uso: rm <rutaynombrearchivo>

• rmdir: Elimina el directorio indicado, el cual debe estar vacío.

Uso: rmdir nombredirectorio

• sudo o su: Con este comando accedemos al sistema como root.

• umount: Desmontar unidades montadas anteriormente

Uso: umount <nombredirectorio>

• wc:Cuenta los caráteres, palabras y líneas del archivo de texto.

Uso: wc nom_archivo

• whereis: Devuelve la ubicación del archivo especificado, si existe.

Uso: whereis nomb_archivo

Larga vida a la consola!!

Boot into single user and run an fsck first.
Unmount the partition that you are wanting to re-create the journal on.
Run the following commands, where sdaX is the actual partition:
————————
tune2fs -O ^has_journal /dev/sdaX
fsck -y /dev/sdaX
tune2fs -j /dev/sdaX
fsck -y /dev/sdaX
————————
This will remove the journal then recreate the journal inode, insuring that it is clean.

Dziś po starcie, system przywitał mnie bez tapety i niektórych ikon aktywatorów. WTF?! Okazało się, że nie zamontowała się partycja na której wspomniane grafiki trzymam. Dlaczego? Bo deweloperzy ubuntu uznali, że system może startować bez montowania mało istotnych partycji (w tym wypadku uruchomił się po prostu na niej fsck).

Kiedyś przebierze się miarka i w końcu wywalę Xubuntu w cholerę, a deweloperzy robią coraz więcej żeby przyspieszyć ten proces.

Chociaż tyle dobrego, że można łatwo się tego pozbyć dodając opcję bootwait do interesujących nas wpisów w /etc/fstab.

źródło

[edit 03/11/2009]
Tia… po dodaniu bootwait uruchamianie systemu staje w momencie montowania partycji…

My fedora 11 linux machine was running good,with faster boot up[ 21 seconds to the login screen ],until I installed WINE in it.As a web-developer,I am in need of IE6,for cross browser compatibility issues that will occur only in that browser,while others are working fine.so I had to install WINE,to run ies4linux script.Unfortunately,after installing WINE,my fedora freezes then and there.I cannot open a browser,I cannot open my back up drive.Everything freezes.Even my cpu2 performance level went for 30-50% increase.Also,WINE runs slowly.I am sure,that ies4linux caused such problem.Also,my booting of fedora went for more than a minute.So I uninstalled WINE and ies4linux,but still my bootup time got slow and my fedora freezes all of the sudden.so I went for reboot and used ‘ctrl+alt+F2′ at the login page.I don’t know what was the problem,so I logged in as root user and run ‘fsck‘ and it solved my problem.It seems that an unwanted script in ies4linux,has blocked my entire fedora.The fsck cleaned it with zero errors and now my fedora is back.

Steps:

1. While rebooting the server from the server), use “shutdown -rf now”. This will restrict the system to run an autofsck.

2. Edit the /etc/grub.conf file and place “fastboot” at the end of the kernel line.

3. Edit the /etc/fstab. You can see two numbers at the end of the line for each partition, change the second number to a 0

Example: /dev/sdd2 / ext3 defaults 1 0). This will have the system mount the partition but will not run a check when booting.

(1)
服务器掉电，系统启动最后显示以下信息：
Enter full puth name of shell or RETURN for /bin/sh:

按回车，到“#”字提示符下输入“fsck -fy”，这时屏幕会显示类似以下的信息，完成后会回到#字符下，这时输入reboot重启机器既可。
**/dev/ad10sla
**last mounted on/
**root file system
**phase 1 – check blocks and sizes

(2)
服务器掉电，系统启动最后显示以下信息：
Starting file system checks:
/dev/ad0s1a:UNEXPECTED INCONSISTENCY;RUN fsck MANUALLY

直接输入fsck -fy dev/ad0s1a 这时屏幕会显示类似以下的信息，完成后会回到#字符下，这时输入reboot重启机器既可。
**/dev/ad10sla
**last mounted on/
**root file system
**phase 1 – check blocks and sizes

(3)
更换硬盘后，系统启动最后显示以下信息：
ad10: 476940MB at ata5-master SATA300
SMP: AP CPU #1 Launched!
Trying to mount root from ufs:/dev/ad4s1a

Manual root filesystem specification:
: Mount using filesystem
eg. ufs:da0s1a
? List valid disk boot devices
Abort manual input

mountroot>

因为原来的硬盘是ad4s1a，现在换硬盘了，接的位置也变了，根据系统提示信息，现在新的硬盘是ad10，所以只需要输入：
mountroot> ufs:ad10s1a 回车就可以继续正常启动系统，进到系统后修改/etc/fstab文件既可！

Well sorry it has taken so long but here is the third installation in the series on the Linux file system. In case you haven’t been following before now, here are the links to part1 and part2.

In this portion I will discuss the following directories/partitions: /lost+found /lib /mnt and /tmp.

/lost+found

So you are working and all of a sudden there is a power outage. Or even worse your system suddenly crashes for no reason. Well the next time you boot up your machine Linux will try to recover any lost data/files. The result of this recovery attempt will be saved here. Sure the files in here might not make much sense but there is a small chance that there might be something that you might be able to actually use. Finally, for those of you that really want to know, this recovery is done by using the fsck command. Look into it yourself, since this isn’t the place to go into depth on it.

/lib

The location of all the shared library files. Think DLL files on Windows.

/mnt

This is the generic place to mount other file systems. Such as internal/external hard drives, CD-ROMS, DVD, and floppy disk if people still use those. For more information on mounting see the link to the post dedicated to this topic.  But I should mention that you can make any location a mount point, but it’s usually a good idea to have them all relatively “close” to each other.  Plus try not to overdo it, because really 50 different mount points might just be a little excessive.

/tmp

Temporary files are stored here. In other words, DON’T SAVE IMPORTANT STUFF HERE! This directory is cleared upon each reboot of the system. As a side note, this is really useful for getting around disk quotas. Just save your files here and then when you restart they will be gone. All you have to do is make sure that you won’t be needing those files ever again.

So I got a new 13″ MacBook Pro recently and have been tinkering around with it. It’s not my main machine (I still have my Dell XPS M1530) but it’s slowly becoming the only one I use. Currently, the only thing I’m using my Dell for is a media hub – I stream my music over iTunes to my Dell which is connected to my speakers…and that’s about it…

So, while tinkering, I did run into a small snag which rendered my mac useless – apparently changing the sharing settings for the ‘everyone’ user of the Macintosh HD to read only will also apply to the admin (even though admin is listed as a separate user) and therefore it wasn’t able to access the drive. Rebooting didn’t help – all I ended up with was a grey screen with the rotating dashes. Kinda silly don’t you think? As an admin, I’d assume that all drives are accessible. I guess I assumed that ‘everyone’ implied ‘everyone else’ – I was wrong

Fearing I had diminished my brand new fruity computer into nothing more than a 1″ thick paper weight, I did a little googling and found a solution: By booting into Single User Mode (Powering up while holding Command+S) and changing the access rights for the drive there, my computer would be revived! So here are the steps I followed (which incidentally saved me the embarrassment and hassle of making a trip to the Genius Bar):

1. Boot up while holding Command + S (boots into Single-User mode)

2. Enter in sbin/fsck -yf

3. Wait for all the checking to finish (took a few minutes)

4. Enter in sbin/mount -uw /

5. Enter in chmod 775 /

And that was it! Reboot and watch as your screen blinks from grey to blue to desktop! Not going to lie, seeing something go wrong on the mac is far more daunting than when something goes wrong on a Windows machine – I think it has something to do with expectations. With Windows its almost expected, with mac, at least in my experience, not so much. Maybe it’s my n00b-iness…

Just wanted to share that with everyone in case you run into something similar!

A month after I published my previous post on this related issue (Ubuntu 9.04 – A very buggy affair!!!), I did some research to fix these problems. Now, my ubuntu is running perfectly ok, and no more problems cropped up.

The few problems that might be reason why the ubuntu was behaving abnormally are -

• It requires frequent disk checks. The disk allocation seems to go haywire after several reboots, and thus needs periodic fscks to fix this.
• It does not do automatic disk check during booting, when on battery power. I’ve noticed quite a few do not connect to the power source when they switch on their notebook. This then disables the automatic fsck checks that the ubuntu usually does when on battery power. Also the period of these checks is actually of longer duration, maybe one check after 20 boots, and this is not good for during that time, the ubuntu can spoil the disk! So you can change that by this command ” sudo tune2fs -c 10 /dev/sda1 “. This sets the number of boots after which the fsck must be done. u can change that number however you like, i suggest 6-10 is good. It works with 10 for me though.
• I noticed that if you forcefully shutdown, then the ubuntu goes haywire! No remedies for that except prevention.

Though the ubuntu is working fine, there are still some nagging problems, like the case when booting under battery power, it needs some user input, otherwise it does nothing, it stays just like that. Any solutions?

This morning I had to replace half of a mirror in my Linux server, which being a home server, meant needing to reboot. (Of course I’d love a server with hot-swappable drives, but I suspect both my partner and I might find the noise of such a server somewhat overwhelming for combination computer-room/office.)

So I shutdown the virtual machines running on the HP ML110 G4 (running VMware Server), shutdown the server itself, swapped the drives and rebooted. I promised my partner that internet access would only be down for about 15 minutes, so of course Murphy decided to play a visit.

“Warning, /dev/sdc1 has not been checked in 191 days. Check forced.”

And wouldn’t you know it, /dev/sdc1 is 917GB, so the check took quite a lot longer than 15 minutes. It’s running on ext3, so checking is required less frequently, but I’m still paranoid enough that for the data housed on that particular filesystem, I’d rather not turn checking off altogether. (That filesystem isn’t mirrored, due to transient data on it.)

Having only just read about btrfs, an upcoming filesystem for Linux, the lengthy delay-on-boot caused by a “large” filesystem check was acutely hammered home. Amongst other things, btrfs promises online checks of the filesystem, as well as fast offline checks of the filesystem – something every storage administrator and system administrator wants. We are at the point where filesystem capacities are routinely too large for conventional exhaustive checks. Many more modern filesystems have already achieved this (e.g., ZFS, VxFS, etc.), but it’s a relief to know that such advances are coming, and coming with corporate sponsorship, to Linux.

For an excellent overview of btrfs, check out this short history published on Linux Weekly News.

Ok, so I got many replies to my earlier post on the ubuntu 9.04 being a buggy affair. Thanks guys for all that.

Actually I happened to meet my cousin online in google chat, and he told me that he faced similar problems with the jaunty jackalope in his desktop. He, after searching, tried out the file system check.

Actually I did try it in the ubuntu 9.04 in the terminal. And is obvious, it’s not safe to do a fsck on a partition already mounted. So I logged into my other ubuntu (8.10) and did the check there. This is the command I typed..

$ sudo e2fsck -f -c -v /dev/sda1

After all the checking, I logged back into jaunty jackalope, and ever since I have been using without any hitch. So the problem seems to me is that the ubuntu requires frequent disk checking, and there is some major bug in this version of ubuntu which is causing so.

Moral of the post : Frequent file system checks a must for any operating systems.

References : http://ubuntuforums.org/showthread.php?t=1155810

technicaldementia.wordpress.com

Warning: The following is for personal note only, and is not meant to be a tutorial or guide.

On Debian server at work, we have /home reside on /dev/hda6 and I want to move to a new hard disk /dev/hdb.

First, I need to format /dev/hdb using fdisk. Then use dd to copy the content from /dev/hda6 to /dev/hdb1, the newly createdd ext3 partition.

# dd if=/dev/hda6 of=/dev/hdb1 bs=1024

The above commands instruct dd to read the content from /dev/hda6 and write it to /dev/hdb1. bs=1024 sets the block size to 1024 bytes.

dd takes a while depends on how big is your hard disk. Then, there is one final step to do — to re-size /dev/hdb1 to its maximum capacity.

# e2fsck -f /dev/hdb1

Now we can resize the file system in /dev/dhb1 partition. If we don’t specify the size, then resize2fs will assume the largest:

# resize2fs /dev/hdb1

# fsck -n /dev/hb1

Sometimes your stressed due to some problem or the lack of time to solve it and you actually don’t think clearly.

This picture shows one of does moments.

Just Say Yes You Noob

PS: There would be a better justification if the glass was with alcool or beer.

Hoy se ha ido la luz en un perímetro no identificado del centro de Almería y al no tener SAI me ha pegado un apagón brusco el equipo.

Al volver la luz arranco el equipo y al ver que carga con naturalidad sigo trabajando pero cual es mi sorpresa que al intentar ejecutar la aplicación que en ese momento tenía cargada, concretamente zim que es una especie de wiki para el escritorio que trabaja con archivos de texto al más puro estilo dokuwiki, veo que no consigue abrir los archivos que se encuentran en la unidad extraible.

Al mirar la salida de dmesg veo lo siguiente:

FAT: Filesystem panic (dev sdd1)
fat_free_clusters: deleting FAT entry beyond EOF
File system has been set read-only

Por lo visto, al “desmontar” de forma brusca el dispositivo me ha fastidiado algo que hace que el dispositivo se monte como solo lectura tanto para root como para mi usuario habitual y buscando por internet encuentro referencias acerca de que este problema puede pasar cuando no se ha desmontado un dispositivo de forma correcta en Windows y que para solucionarlo hay que volver a Windows y ejecutar el comando chkdsk o algo así.

En realidad no se si tiene mucho que ver, ya que yo no trabajo con Windows aunque imagino que es algo inherente en el sistema de ficheros FAT el cual utilizo en pendrives por cuestiones de compatibilidad aunque después de esto estoy pensando muy mucho en dejar de utilizarlo…

El problema, es que no tengo ningún Windows a mano para hacerle un “cehachekadeeseka” y la verdad es que no suelo tenerlo por lo que buscando otra solución he encontrado una utilidad GNU/Linux que me ha solucionado el problema. El comando en cuestión ha sido el siguiente:

# fsck.msdos -a /dev/sdd1

La aplicación en cuestión viene incluida dentro del paquete dosfstools, y por si alguien quiere indagar en las posibilidades de este juego de herramientas dejo alguna información al respecto:

$ aptitude show dosfstools
Paquete: dosfstools
Estado: instalado
Instalado automáticamente: sí
Versión: 3.0.2-1
Prioridad: opcional
Sección: otherosfs
Desarrollador: Daniel Baumann <daniel@debian.org>
Tamaño sin comprimir: 221k
Depende de: libc6 (>= 2.3)
Descripción: utilities for making and checking MS-DOS FAT filesystems
The dosfstools package includes the mkdosfs (aka mkfs.dos and mkfs.vfat) and dosfsck (aka fsck.msdos and fsck.vfat) utilities, which respectively make and check MS-DOS FAT
filesystems on hard drives or on floppies.

This version uses the enhanced boot sector/superblock format of DOS 3.3+ as well as provides a default dummy boot sector code.
Página principal: http://www.daniel-baumann.ch/software/dosfstools/

$ apt-file show dosfstools | grep bin/
dosfstools: /sbin/dosfsck
dosfstools: /sbin/fsck.msdos
dosfstools: /sbin/fsck.vfat
dosfstools: /sbin/mkdosfs
dosfstools: /sbin/mkfs.msdos
dosfstools: /sbin/mkfs.vfat

Berawal dari harddisk Maxtor 120GB ku yang udah penuh… maka diriku secara spontanitas memiliki dua pemikiran… pertama… beli harddisk eksternal baru… namun karena harganya yang 1TB masih 1jutaan lebih maka timbulah pemikiran kedua… menghapus file-file yang ngga perlu untuk sementara… ini bukan karena anti-mahal (ehm… uhuk… anti-mahal = pelit) loh…

Setelah 10 menit kluar masuk folder, delet file sana-sini, tetep aja ngga cukup memberikan ruang kosong yang cukup ideal untuk harddisk ini… maka diambil inisiatif untuk mendelet beberapa master software yang sbenernya cukup berharga sih…

Eh ternyata secara tidak terduga-duga ada beberapa master software yang bercokol di partisi NTFS ini engga mau di hapus… muncul jeritan teraniaya…

rm:cannot remove ‘xxx’: Input/output error

Waduh! Ya udah kalo kayak gini alamat cuman ada dua… partisi nya rusak atau bad sector! Harap-harap cemas supaya partisinya aja yang rusak dan bukan alamat yang terakhir…

Refleks langsung ketik perintah “fsck /dev/sdb1” karena kebetulan sdb1 adalah device untuk si Maxtor tadi… tapi lagi-lagi muncul jeritan protes… kali ini bukan dari hardisk tapi oleh si Xubuntu…

fsck 1.41.4 (27-Jan-2009)
fsck: fsck.ntfs: not found
fsck: Error 2 while executing fsck.ntfs for /dev/sdb1

Waduh! Ya udah kalo kayak gini alamat cuman ada dua… tanya google atau mbanting hardisk! Harap-harap cemas supaya google punya jawabnya dan bukan alamat yang terakhir…

Refleks langsung bukak Firefox trus google mencari si fsck.ntfs ini… dan apa yang terjadi sodara-sodara? Ternyata fsck.ntfs itu emang ngga ada… cuman ada kalimat penghibur “fsck.ntfs hopefully soon…”  Yay! Langsung kebayang pengen mbanting hardisk inih…

Mencoba menenangkan diri… akhirnya diriku menginstall “ntfsprogs” sebuah kumpulan tools untuk ngobrak-abrik paritisi NTFS… dan kutemukan disana sebuah perintah “ntfsfix” yang dengan penuh harapan dapat memperbaiki masalah tadi… langsung aja ta jalankan…

Ntfsfix sukses berjalan dengan jeritan keberhasilan kalo udah berhasil di perbaiki… dan aku pun mencoba untuk mendelete file yang ogah di delete tadi…

TETEP ENGGA SUKSES! JERITAN YA SAMA MASIH BERGEMA!

Tampaknya ntfsfix ini engga menjalankan tugasnya dengan sempurna… terpaksa gw menggunakan tools yang laen… “ntfsresize”… masih satu paket dari “ntfsprogs” tadi… cuman tools ini sebenernya untuk me-resize ukuran partisi… tapi bisa juga di gunakan untuk sekedar mengecek integritas partisi… caranya… pake perintah…

ntfsresize –fi [device harddisk]

Kalo ngga tau device hardisk mu yang mana coba di list dulu pake perintah…

fdisk -l

Seperti pada gambar dibawah ini

Sayangnya “ntfsresize” cuman bisa ngecek aja… tapi ngga bisa dibenerin… ngga bisa di fix… ya udah otomatis… pake chkdsk /f nya windows… huh!

File System Check on your system

fsck command using to check ur file system

unmount the file system which you want to check

Take system down to runlevel one

# init 1 //superuser mode

Unmount file system, for example if it is /home (/dev/sda2) file system then type command:

# umount /home or # umount /dev/sda2 then

# fsck /dev/sda2 then

# fsck.ext3 /dev/sda2 //if your sda2 is ext3

if any files recovered then they found in /home/lost+found directory

# mount /home //mount which you did unmount

# init 3 // goto multiuser mode

If you have any doubt regarding this please clarify and you have to do the above instruction carefully else you will be losing all your important data

Thanks to debian blogs