# fsck_ufs in single user mode



## MNIHKLOM (Nov 29, 2012)

Hi,

Do we need to run fsck_ufs all file systems all the times when droping into a single user mode ?  And I wonder if swap file systems needed to run fsck too ?

Thank you for any helps.

With best regards,
MNIHKLOM


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## wblock@ (Nov 29, 2012)

No, fsck(8) generally only needs to be run when there has been a power loss or some suspicion of filesystem problems.

Swap is not a filesystem at all, so does not need checking.


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## jb_fvwm2 (Nov 29, 2012)

I use fsck_ffs -y weekly, most of the time after Xorg crashes, sometimes to fix the filesystem on a thumbdrive that has "stuck" ( one-line errors ( such as "could  not read superblock" ) mostly are unexpectedly fixed by that command...  maybe it is just luck or the same situation just happening repeatedly more often than other less fixable ones.)   The point being, I should have known about it years ago, could have saved time and data.


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## MNIHKLOM (Nov 29, 2012)

Hi,

I thank you all for valuable hints and for your times.  I have just known about swap is not a file system and fsck_ffs usage for the first time here.

With best regards,
MNIHKLOM


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## sk8harddiefast (Nov 29, 2012)

In fact swap needs when ram is full and system has nospace to write data. So move ram's data to swap to free some memory in ram. If a procedure is on swap then call it back to ram to execute it. So swap don't need fsck and also is not needed if you have a lot of memory on your computer.
The good about swap is that hard disks are cheap and you can have a lot of swap.
The bad about swap is that hard disks don't read/write data with the same speed as ram do.


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