From: Phillip Susi <psusi@ubuntu.com>
To: Hugo Mills <hugo@carfax.org.uk>,
Hans Stimer <hans.stimer@gmail.com>,
linux-btrfs <linux-btrfs@vger.kernel.org>
Subject: Re: Packed small files
Date: Fri, 10 Feb 2012 14:02:26 -0500 [thread overview]
Message-ID: <4F3569C2.7090809@ubuntu.com> (raw)
In-Reply-To: <20120131164610.GE5531@carfax.org.uk>
-----BEGIN PGP SIGNED MESSAGE-----
Hash: SHA1
On 1/31/2012 11:46 AM, Hugo Mills wrote:
> So you're looking at a minimum of 413 bytes of metadata overhead
> for an inline file, plus the length of the filename.
>
> Also note that the file is stored in the metadata, so by default
> it's stored with DUP or RAID-1 replication (even if data is set to
> be "single"). This means that you'll actually use up twice this
> amount of space on the disks, unless you create the FS with
> metadata set to "single".
>
> I don't know how these figures compare with other filesystems. My
> entirely uneducated guess is that they're probably comparable,
> with the exception of the DUP effect.
On ext4 you are looking at 256 bytes for the inode, name length + a
few bytes for the directory entry, another few bytes for the hashed
directory entry, and a whole 4k block to hold the data, so ~4300 bytes
( + name length ) of overhead to store a 64 byte file.
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.17 (MingW32)
Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/
iQEcBAEBAgAGBQJPNWnBAAoJEJrBOlT6nu75lVkIAIO2mjYeVK5BbMNfw5HJ7jZO
WfIBv5xR8V06e0VLgv4FQqPlWcm+ZQHorYDM7h15q4cIgoZ3x0P3n3bSCurFRLfF
lSRjn/fsX1Y9isPEB6/monPm+08U6qh7jXGldEMOLKaA7VG/QOVR01k3W2a3FkJ4
kWBjEbK/xE013WaQnfR26PydRT8ILRzGUE4uEKGsdV39JkcEorQ1lDg+XWz5Hvy7
VmelT21272PssIUbRub1QkZXj6p0SUu1zeU1IwOdt6X1uXFcWqFbBFRGJk4f2+ZM
5MquuVC+YrzfDIBnS0ZBZ4UqNmxYuPCSzTLlpPiJJiY/AwR7916H/CoF5k38k/M=
=8YmX
-----END PGP SIGNATURE-----
prev parent reply other threads:[~2012-02-10 19:02 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-31 16:21 Packed small files Hans Stimer
2012-01-31 16:46 ` Hugo Mills
2012-02-10 19:02 ` Phillip Susi [this message]
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=4F3569C2.7090809@ubuntu.com \
--to=psusi@ubuntu.com \
--cc=hans.stimer@gmail.com \
--cc=hugo@carfax.org.uk \
--cc=linux-btrfs@vger.kernel.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).