linux-ext4 - Re: Extent Depth Histogram Fsck

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Date:	Tue, 26 Jun 2012 09:40:59 -0600
From:	Andreas Dilger <adilger@...ger.ca>
To:	"Nelson, John R" <John_Nelson@...dent.uml.edu>
Cc:	"linux-ext4@...r.kernel.org" <linux-ext4@...r.kernel.org>
Subject: Re: Extent Depth Histogram Fsck

On 2012-06-26, at 8:34 AM, Nelson, John R wrote:
> What does the extent depth histogram mean? Is it a measure of something?
> 
> like mine is 
> 
> 
> Extent depth histogram: 36010/81

This means that of all the extent-mapped files in the filesystem,
36010 files have an extent tree of depth 0 (i.e. they fit inside the inode)
81 files have an extent tree of depth 1 (i.e. there is a single index block)

Typically, files larger than 4 * 128MB = 512MB need an index block, but if
the maximum-sized extents cannot be allocated then an index block will be needed for smaller files.  Only if you have very large files (> 40GB),
or a very fragmented free space would you need more than a single level
of index blocks.

Cheers, Andreas

--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html