FSCK komutları ile Linux Dosya Sisteminin Kontrolü ve Tamiri

Merhaba Değerli Ziyaretçimiz

Bu makalemizde sizlere Linux sistemlerde FSCK komutları ile disk yada disklerinizi nasıl kontrol ve tamir edebileceğinizi anlatacağız.Bu makalede, herhangi bir dosya sisteminin hatalarını gidermek ve düzeltmek için fsck komutunu kullanımıyla ilgili 10 pratik örnek anlatılacaktır.

1- Bir Disk Bölümü Üzerindeki Dosya Sisteminin Kontrolü

Öncelikle Parted komutunu kullanarak sisteminizdeki uygun bölümleri aşağıda gördüğünüz gibi görüntüleyelim.

# parted /dev/sda 'print'

Number  Start   End     Size    Type      File system  Flags
 1      1049kB  106MB   105MB   primary   fat16        diag
 2      106MB   15.8GB  15.7GB  primary   ntfs         boot
 3      15.8GB  266GB   251GB   primary   ntfs
 4      266GB   500GB   234GB   extended
 5      266GB   466GB   200GB   logical   ext4
 6      467GB   486GB   18.3GB  logical   ext2
 7      487GB   499GB   12.0GB  logical   fat32        lba

Yada aşağıda görüldüğü gibi belirli bir dosya sistemini de kontrol edebilirsiniz.(Örn. /dev/sda6)

# fsck /dev/sda6
fsck from util-linux 2.20.1
e2fsck 1.42 (29-Nov-2011)
/dev/sda6: clean, 95/2240224 files, 3793506/4476416 blocks

Aşağıdakiler Fsck komutu için mümkün olan çıkış kodlarıdır.

• 0 – Hata yok
• 1 – Dosya sistemi hatası düzeltildi
• 2 – Sistem yeniden başlatılmalıdır.
• 4 – Dosya sistemi hataları düzeltilmedi.
• 8 – Operasyon hatası
• 16 – Kullanım yada sözdizimi (syntax) hatası
• 32 – Fsck kullanıcı isteği ile iptal edildi.
• 128 – Paylaşımlı kütüphane hatası

2. Fsck Command Specific to a Filesystem Type

fsck dahili bir dosya kontrol işlemi için ilgili dosya denetleyicisi komutu kullanır. Bu fsck checker komutlar genellikle / sbin altında bulunur.

Aşağıdaki örnek, çeşitli olası fsck denetleyicisi komutları gösterir. (Örnek: fsck.ext2, fsck.ext3, fsck.ext4, vs….)

# cd /sbin
# ls fsck*
fsck  fsck.cramfs  fsck.ext2  fsck.ext3  fsck.ext4  fsck.ext4dev  fsck.minix  fsck.msdos  fsck.nfs  fsck.vfat

fsck komutu kontrol edilir dosya için bir dosya sistemi denetimi bulamaması durumunda bir hata verecektir.

Bir NTFS bölümü üzerinde fsck çalıştırmak için örneğin, aşağıdaki hata iletisini alırsınız. / Sbin altında hiçbir fsck.ntfs yoktur. Yani, bu aşağıdaki hata iletisini verir.

# fsck /dev/sda2
fsck from util-linux 2.20.1
fsck: fsck.ntfs: not found
fsck: error 2 while executing fsck.ntfs for /dev/sda2

3. Hepsi bir arada Dosya sistemleri Giriş Seçeneği kullanarak çalıştırın

Bu seçeneği kullanarak fsck tek bir vadede bütün dosya sistemlerini kontrol edebilirsiniz. Bu / etc / fstab her dosya için belirtilen alanın değeri tarafından verilen sırayla dosya sistemini denetler.

Unutmayın 0 alanın değeri değeri ile dosya atlanır ve 0’dan büyük sırayla kontrol edilir

/ etc / fstab, aşağıda listelenen gibi girdileri içerir

# cat /etc/fstab

##
proc            /proc           proc    nodev,noexec,nosuid 0       0
## / was on /dev/sda5 during installation
/dev/sda5 /               ext4    errors=remount-ro 0       1
## /mydata was on /dev/sda6 during installation
/dev/sda6 /mydata         ext2    defaults        0       2
## /backup was on /dev/sda7 during installation
/dev/sda7 /backup         vfat    defaults        0       3

Burada, aynı alanın değeri dosya sistem içinde paralel olarak kontrol edilir.

# fsck -A

kök dosya sistemi bu global onay sırasında  aşağıda gösterildiği gibi  -R seçeneğini ekleyerek  önerilir.

# fsck -AR -y
fsck from util-linux 2.20.1
e2fsck 1.42 (29-Nov-2011)
/dev/sda6: clean, 95/2240224 files, 3793506/4476416 blocks
dosfsck 3.0.12, 29 Oct 2011, FAT32, LFN
/dev/sda7: 8 files, 50/1463400 clusters

Not: Seçenek -y aşağıdaki örneklerden biri de açıklanmıştır.

4. Check Only a Specific Filesystem Type using Option -t

Using fsck -t option, you can specify the list of filesystem to be checked. When you are using with option -A, the fsck will check only the filesystem mentioned with this option -t. Note that fslist is a comma separated values.

Now, pass ext2 as the fslist value to -t option as shown below:

# fsck -AR -t ext2 -y
fsck from util-linux 2.20.1
e2fsck 1.42 (29-Nov-2011)
/dev/sda6: clean, 11/2240224 files, 70327/4476416 blocks

In this example, /dev/sda6 is the only partition created with the filesystem ext2, thus it get checked accordingly.

Using the keyword ‘no’ in front of filesystem, you can check all other filesystem types except a particular filesystem.

In the following example, ext2 filesystem is excluded from the check.

# fsck -AR -t noext2 -y
fsck from util-linux 2.20.1
dosfsck 3.0.12, 29 Oct 2011, FAT32, LFN
/dev/sda7: 0 files, 1/1463400 clusters

5. Don’t execute Fsck on Mounted Filesystem using Option -M

It is a good idea to use this option as default with all your fsck operation. This prevents you from running fsck accidentally on a filesystem that is mounted.

# mount | grep "/dev/sd*"
/dev/sda5 on / type ext4 (rw,errors=remount-ro)
/dev/sda6 on /mydata type ext2 (rw)
/dev/sda7 on /backup type vfat (rw)

As shown above, /dev/sda7 is mounted. If you try to execute fsck on this /dev/sda7 mounted filesystem (along with the -M option), fsck will simply exit with the exit code 0 as shown below.

# fsck -M /dev/sda7
# echo $?
0

6. Skip the Display Title using Option -T

Using option -T, you can skip the title get displayed in the beginning of fsck command output.

# fsck -TAR
e2fsck 1.42 (29-Nov-2011)
/dev/sda6 is mounted.  e2fsck: Cannot continue, aborting.
dosfsck 3.0.12, 29 Oct 2011, FAT32, LFN
/dev/sda7: 8 files, 50/1463400 clusters

Note that the title is something like “fsck from util-linux 2.20.1″.

7. Force a Filesystem Check Even if it’s Clean using Option -f

By default fsck tries to skip the clean file system to do a quicker job.

# fsck /dev/sda6
fsck from util-linux 2.20.1
e2fsck 1.42 (29-Nov-2011)
/dev/sda6: clean, 95/2240224 files, 3793503/4476416 blocks

You can force it to check the file system using -f as shown below.

# fsck /dev/sda6 -f
fsck from util-linux 2.20.1
e2fsck 1.42 (29-Nov-2011)
Pass 1: Checking inodes, blocks, and sizes
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
/dev/sda6: 95/2240224 files (7.4% non-contiguous), 3793503/4476416 blocks

8. Attempt to Fix Detected Problems Automatically using Option -y

In the following example, /dev/sda6 partition is corrupted as shown below.

# mount /dev/sda6 /mydata
# cd /mydata
# ls -li
ls: cannot access test: Input/output error
total 72
  49061 -rw-r--r--  1 root root     8 Aug 21 21:50 1
  49058 -rw-r--r--  1 root root 36864 Aug 21 21:24 file_with_holes
  49057 -rw-r--r--  1 root root  8192 Aug 21 21:23 fwh
     11 drwxr-xr-x  2 root root 49152 Aug 19 00:29 lost+found
2060353 ?rwSr-S-wT 16 root root  4096 Aug 21 21:11 Movies
      ? -?????????  ? ?    ?        ?            ? test

As seen above, the directory Movies and a file test attributes are invalid.

In the following example, -y will pass “yes” to all the questions to fix the detected corruption automatically.

# fsck -y /dev/sda6
fsck from util-linux 2.20.1
e2fsck 1.42 (29-Nov-2011)
/dev/sda6 contains a file system with errors, check forced.
Pass 1: Checking inodes, blocks, and sizes
Inode 2060353 is a unknown file type with mode 0137642 but it looks
like it is really a directory.
Fix? yes

Pass 2: Checking directory structure
Entry 'test' in / (2) has deleted/unused inode 49059.  Clear? yes

Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information

/dev/sda6: ***** FILE SYSTEM WAS MODIFIED *****
/dev/sda6: 96/2240224 files (7.3% non-contiguous), 3793508/4476416 blocks

9. Avoid Repair, but Report Problems to Stdout using Option -n

It is possible to print such detected problems into stdout without repairing the filesystem using fsck -n option.

First, you could notice/see the problem in partition /dev/sda6 that the Movies directory (and fwh file) doesn’t have valid attribute details.

# mount /dev/sda6 /mydata
# cd /mydata
# ls -lrt
total 64
drwxr-xr-x  2 root root 49152 Aug 19 00:29 lost+found
?--xrwx-wx 16 root root  4096 Aug 21 21:11 Movies
?-----x-wx  1 root root  8192 Aug 21 21:23 fwh
-rw-r--r--  1 root root 36864 Aug 21 21:24 file_with_holes
-rw-r--r--  1 root root     8 Aug 21 21:50 1

The above problem in the specific partition displayed in stdout without doing any fix on it as follows,

The following fsck example displays the problem in the stdout without fixing it. (partial output is shown below).

# fsck -n /dev/sda6
fsck from util-linux 2.20.1
e2fsck 1.42 (29-Nov-2011)
/dev/sda6 contains a file system with errors, check forced.
Pass 1: Checking inodes, blocks, and sizes
Inode 2060353 is a unknown file type with mode 0173 but it looks
like it is really a directory.
Fix? no
Inode 2060353, i_blocks is 8, should be 0.  Fix? no

Pass 2: Checking directory structure
Inode 2060353 (/Movies) has invalid mode (0173).
Clear? no

Inode 49057 (/fwh) has invalid mode (013).
Clear? no

Entry 'fwh' in / (2) has an incorrect filetype (was 1, should be 0).
Fix? no

Pass 3: Checking directory connectivity
Unconnected directory inode 65409 (???)
Connect to /lost+found? no

'..' in ... (65409) is ??? (2060353), should be  (0).
Fix? no

Unconnected directory inode 2076736 (???)
Connect to /lost+found? no

Pass 4: Checking reference counts
Inode 2 ref count is 4, should be 3.  Fix? no

Inode 65409 ref count is 3, should be 2.  Fix? no

Inode 2060353 ref count is 16, should be 15.  Fix? no

Unattached inode 2060354
Connect to /lost+found? no

Pass 5: Checking group summary information
Block bitmap differences:  -(164356--164357) -4149248
Fix? no

Directories count wrong for group #126 (1, counted=0).
Fix? no

/dev/sda6: ********** WARNING: Filesystem still has errors **********

/dev/sda6: 96/2240224 files (7.3% non-contiguous), 3793508/4476416 blocks

10. Automatically Repair the Damaged Portions using Option -a

In order to repair the damaged portion automatically ( without any user interaction ), use the option -a as shown below.

# fsck -a -AR

The option -a is same as -p in e2fsck utility. It cause e2fsck to fix any detected problems that has to be safely fixed without user interaction.

In case when fsck requires administrator’s attention, it simply exits with error code 4 before printing the description of the problem.

# fsck -a /dev/sda6
fsck from util-linux 2.20.1
/dev/sda6 contains a file system with errors, check forced.
/dev/sda6: Inode 2060353 is a unknown file type with mode 0173 but it looks
like it is really a directory.

/dev/sda6: UNEXPECTED INCONSISTENCY; RUN fsck MANUALLY.
	(i.e., without -a or -p options)

# echo $?
4

As you remember, fsck -y option can be used here to fix the above issue automatically.

# fsck -y /dev/sda6
fsck from util-linux 2.20.1
e2fsck 1.42 (29-Nov-2011)
/dev/sda6 contains a file system with errors, check forced.
Pass 1: Checking inodes, blocks, and sizes
Inode 2060353 is a unknown file type with mode 0173 but it looks
like it is really a directory.
Fix? yes

Pass 2: Checking directory structure
Inode 49057 (/fwh) has invalid mode (013).
Clear? yes

Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information
Block bitmap differences:  -(164356--164357)
Fix? yes

Free blocks count wrong for group #5 (0, counted=2).
Fix? yes

Free blocks count wrong (682908, counted=682910).
Fix? yes

/dev/sda6: ***** FILE SYSTEM WAS MODIFIED *****
/dev/sda6: 95/2240224 files (7.4% non-contiguous), 3793506/4476416 blocks

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