FSCK

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 FSCK (File System Consistency Check) 
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 What does FSCK do? 
 fsck (file system consistency check) is a system utility used to check and repair filesystems. FSCK is made up of various tools that are made to handle different filesystem types, these are stored within /usr/sbin: 
 lrwxrwxrwx 1 root root         8 Mar 23  2022 dosfsck -> fsck.fat
-rwxr-xr-x 1 root root    360280 Jun  1  2022 e2fsck
-rwxr-xr-x 1 root root     43440 Apr  9 15:32 fsck
-rwxr-xr-x 1 root root      1185 Feb 24  2022 fsck.btrfs
-rwxr-xr-x 1 root root     31168 Apr  9 15:32 fsck.cramfs
lrwxrwxrwx 1 root root         6 Jun  1  2022 fsck.ext2 -> e2fsck
lrwxrwxrwx 1 root root         6 Jun  1  2022 fsck.ext3 -> e2fsck
lrwxrwxrwx 1 root root         6 Jun  1  2022 fsck.ext4 -> e2fsck
-rwxr-xr-x 1 root root     84360 Mar 23  2022 fsck.fat
-rwxr-xr-x 1 root root     55712 Apr  9 15:32 fsck.minix
lrwxrwxrwx 1 root root         8 Mar 23  2022 fsck.msdos -> fsck.fat
lrwxrwxrwx 1 root root         8 Mar 23  2022 fsck.vfat -> fsck.fat
-rwxr-xr-x 1 root root      1968 Feb  9  2022 fsck.xfs
-rwxr-xr-x 1 root root     51592 Nov  1  2022 ntfsclone
-rwxr-xr-x 1 root root     35200 Nov  1  2022 ntfscp 
 Purpose of fsck 
 
 Checking Filesystem Integrity: It scans the filesystem for inconsistencies and potential errors, such as corrupted metadata, lost clusters, and bad sectors. 
 Repairing Errors: fsck can fix detected issues to prevent data loss and improve system stability. 
 
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 You can only run a filesystem check on an unmounted disk. 
 Scanning a specific disk (optional repair): 
 fsck -t ext4 /dev/sda2 
 Scanning all disks (optional repair) 
 fsck -A 
 FSCK Options: 
 
 
 
 -A 
 Check all filesystems. 
 
 
 -t [option] 
 Specify filesystem type 
 
 
 -y 
 Automatically attempt to fix any errors without user prompt 
 
 
 -n 
 Do not attempt to repair 
 
 
 -f 
 Forces a check, even if the filesystem appears to be fine 
 
 
 -T  
 Skip mounted filesystems 
 
 
 -R 
 Skip the root filesystem 
 
 
 
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 FSCK on boot 
 FSCK can be configured to run for each filesystem when the server boots. For more info see here. 
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