[ale] 1/3 full disk, but it is full?

Joseph A. Knapka jknapka at earthlink.net
Wed Jul 11 11:53:38 EDT 2001


Mel Burslan wrote:
> 
> In the light of this message, one thing comes to mind: How fragmented
> your LARGE files are. Because, if my old knowledge of inodes and linked
> list structures are still serving me good, you are using one inode per
> fragment. And by my gut feeling, large, but really large files, are the
> files accessed and written over many many times by different
> users/processes, which can get badly fragmented. If this is the case,
> you may run out of inodes even with few large files. Just a thought, not
> even worth 2 cents ;-)
> 

You may be thinking of indirect blocks. In ext2 (I think), the inode
block contains a list of the disk blocks comprising the file. Those
blocks
can be anywhere on the disk; the order of the list in the inode
determines the logical order of blocks in the file. If there
are more blocks than can fit in an inode's list, some of the inode block
pointers point to disk blocks that contain not file data, but additional
lists of blocks in the file; the list block is an "indirect" block,
(or maybe the blocks it points to are called indirect blocks, I
can't remember). An indirect block is just another block, not an inode;
there really should be only one node per file or directory.

Of course we're talking about Reiserfs here, so that's probably
completely irrelevant.

-- Joe Knapka
"You know how many remote castles there are along the gorges? You
 can't MOVE for remote castles!" -- Lu Tze re. Uberwald
// Linux MM Documentation in progress:
// http://home.earthlink.net/~jknapka/linux-mm/vmoutline.html
* Evolution is an "unproven theory" in the same sense that gravity is. *
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