fsck errors: "inode 'x', i_block is 'y', should be 'z'." What does it mean

[richard_chapman]

I think this is a general linux file system question. I am unfairly trying to harvest the centos community expertise.
I have a "non centos" system that often produces a bunch of these fsck errors at boot time:
--------------
***** File system check forced at Mon Mar 18 14:09:22 WST 2013 *****
fsck from util-linux-ng 2.17.2
e2fsck 1.41.14 (22-Dec-2010)
Pass 1: Checking inodes, blocks, and sizes
...
Inode 9210997, i_blocks is 351440, should be 351448. Fix? yes

Inode 9211000, i_blocks is 408848, should be 408856. Fix? yes

Inode 9211003, i_blocks is 368016, should be 368024. Fix? yes

Inode 9211006, i_blocks is 345744, should be 345752. Fix? yes
...
Pass 2: Checking directory structure
Pass 3: Checking directory connectivity
Pass 4: Checking reference counts
Pass 5: Checking group summary information

/dev/mapper/c-c: ***** FILE SYSTEM WAS MODIFIED *****
/dev/mapper/c-c: 51331/30285824 files (1.5% non-contiguous), 335005738/484573184 blocks
-------------

Note that in all cases the iblock "should be" 8 more than it "is".

The system has no other obvious related symptoms - and no hardware warnings or errors.

I have done a bit of searching - and now think I know what an inode is and an i_block.
The literature suggests improper shut down as the most likely cause - but I doubt this is the case here.

I have done a "find -inum" to identify some of the suspect files - and they seem to be windows backup files written to the samba share over the network by windows 7 backup.

2 Questions:
1) How does fsck know what the iblock "should be"? Can I trust its decision?
2) Apart from an improper shut down - any other ideas why this is happening?

Thanks

Richard.

[gerald_clark]

Try the forum for your "non--centos" system.

[richard_chapman]

I have - but without any luck...... I always get more useful and helpful information here for my CentOS system........

[AlanBartlett]

Moved to [i]CentOS Social[/i].