How to is file system has errors.. and how to clean them

[Dis93]

I noticed on boot my Zero had a dirty bit set (dirty..dirty..dirty bit)
I ran fsck -n which removed the dirty bit but but obviously didn't check or repair my sd card.
So how does one;

a - check to see if the filesystem needs repair
b - repair the system

I know you can't fully repair a live system so what do you do? In the case of a Pi, if you have another Pi can you use a USB sd card reader and scan the system? Can you scan and repair the sd card via an sd card reader on a *nix/Mac/Win box?

I did try and search the forum for this, but grief me if this question is obvious to a greybeard

[Dis93]

OMG.. title gore.. should have been How to see if the file system has errors.. and how to clean them.

[CarlRJ]

Do this:

Code: Select all

sudo touch /forcefsck

And the next time you reboot, the filesystem will get fsck'd before it gets mounted.

[Dis93]

Thank you!
I knew it'd be something simple