http://www.computerhope.com/unix/fsck.htm

Warning! Do not run fsck on a mounted filesystem! If you run fsck on a filesystem that is currently mounted, you will (at best) receive an error message, and (at worst) corrupt your filesystem data. If you’re going to check your filesystem with fsck, drop into single-user mode and make sure the filesystem is unmounted before you proceed.

Dropping Into Single-User Mode

These instructions should help you bring your Linux system into single-user mode and unmount any filesystems you’d like to check with fsck.

First, initiate runlevel 1 (single-user mode) with the init command:

sudo init 1

Now unmount the filesystem using umount. For instance, if /home is mounted on /dev/sda2, you could run:

umount /home

…or:

umount /dev/sda2

Make sure to run umount for any filesystem you want to check with fsck.

Checking Filesystems

fsck /dev/sda2

This command will attempt to check /dev/sda2, and report any errors it finds.

fsck -y /dev/sda2

Check /dev/sda2, and attempt to automatically fix any errors found.

fsck -A

Check all configured filesystems. fsck will process the file /etc/fstab and check all file systems listed there. Systems will be checked in order of their <pass> value, as listed in the fstab file. Systems with a pass value of 0will be skipped; the system with a pass value of 1 will be listed first, and remaining systems will be checked in ascending order of their pass value.

cat /etc/fstab

View all configured filesystems. Output will resemble the following:

# /etc/fstab: static file system information.
#
# Use 'blkid' to print the universally unique identifier for a
# device; this may be used with UUID= as a more robust way to name devices
# that works even if disks are added and removed. See fstab(5).
#
# <file system> <mount point>   <type>  <options>       <dump>  <pass>
# / was on /dev/sda5 during installation
UUID=c3a6839b-00f1-4cf4-8b00-e61fbcdba6c0 /               ext4    errors=remount-ro 0       1
# /home was on /dev/sda7 during installation
UUID=afceabb6-a3f4-41c2-9ae6-0393d85c7c70 /home           ext4    defaults        0       2
# swap was on /dev/sda6 during installation
UUID=c6ca8b8f-0b46-4c06-a934-a9dd3525faa7 none            swap    sw              0       0
#/dev/sdb1       /media/usb0     auto    rw,user,noauto  0       0

ls /sbin/fsck.*

View all filesystems that can be checked with fsck. Filesystems will appear as extensions to the fsck.* files; for example:

fsck.cramfs  fsck.ext3  fsck.ext4dev  fsck.minix  fsck.nfs      fsck.reiserfs  fsck.xfs
fsck.ext2    fsck.ext4  fsck.jfs      fsck.msdos  fsck.reiser4  fsck.vfat

fsck -n /dev/sda2

Check /dev/sda2 for errors, but do not attempt to repair them; instead, print any errors to standard output.

fsck -f /dev/sda2

Normally, fsck will skip parts of the filesystem marked as “clean” — meaning all pending writes were successfully made. The -f (“force”) option specifies that fsck should check parts of the filesystem even if they are not “dirty”. The result is a less efficient, but a more thorough check.

fsck -t ext2 /dev/fd0

This command will check the ext2 filesystem on the floppy diskette device /dev/fd0.

Related commands

mkfs — Build a Linux file system, usually a hard disk partition.

1. Once seemingly installed successfully from full-iso DVD. But once installed libusb pkg had gone and even cannot be found on the list of the synaptic package manager.  Many errors on fsck -nf. Decided re-install.

2.  None of the disc cannot start from the CD-ROM start configurarion.  (Even the “System Recovery CD”) All fails with edd related message.

3. Reinstall vista business: successful.

4. On vista, install from CD (debian wheezy amd64 netinst).

5. English selected for installation.

6. software collection: check all except Print server, File server, Mail server. (Web, SQL, DNS, Laptop … intact)

7. Going smoothly.

8. Synaptic package manager runs reasonable: repository can be managed.

1. esc キーを押しながら電源投入

2. 変更して終了：　[Fn} End

The following deals withe case of migrating wordpress site to existing wordpress site.

1. Back up “.htaccess” and “wp-config.php”.

2. Delete all the directories: namely “wp-admin”, “wp-content”, “wp-includes” and other if any.

3. ftp all the directories. : visit: one warning and one fatal error

4. ftp files in the root directory. : visit: データ確立エラー

5. restore “wp-config.php” from the backup.: visit: nothing appears.

6.restore “.htaccess” from the backup.:visit: nothing appears.

7.