Date: Tue, 18 Jan 2005 12:57:00 +0000 From: Matthew Seaman <m.seaman@infracaninophile.co.uk> To: Anthony Atkielski <atkielski.anthony@wanadoo.fr> Cc: freebsd-questions@freebsd.org Subject: Re: Backups / Dump etc Message-ID: <20050118125700.GA72972@gravitas.thebunker.net> In-Reply-To: <1537802471.20050114224944@wanadoo.fr> References: <f17daf04050114090052fc6253@mail.gmail.com> <20050114145740.A11218@starfire.mn.org> <1537802471.20050114224944@wanadoo.fr>
next in thread | previous in thread | raw e-mail | index | archive | help
--BXVAT5kNtrzKuDFl
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable
On Fri, Jan 14, 2005 at 10:49:44PM +0100, Anthony Atkielski wrote:
> John writes:
>=20
> J> If you are running FreeBSD 5.x, you get the cool "L" option on
> J> dump which will automatically snapshot the mounted filesystems.
>=20
> What exactly is meant by a "snapshot," and how much extra disk space
> does it require when dump runs? I've seen the warnings when I run dump
> on a running multiuser system in 5.x, and I turned on the L option,
> since I'm not hurting on disk space, but I do wonder how much space it
> requires (I can't imagine a snapshot that doesn't require a lot of disk
> space).
Actually the snapshot requires practically no additional space: it's a
view of the filesystem at a particular point in time. Any subsequent
modifications -- new or edited or deleted files, etc. are held in
memory: they do take up a bit more space, but only until dump(8)
finishes running and all of the recent filesystem traffic can be
merged.
Cheers,
Matthew
--=20
Dr Matthew J Seaman MA, D.Phil. 8 Dane Court Manor
School Rd
PGP: http://www.infracaninophile.co.uk/pgpkey Tilmanstone
Tel: +44 1304 617253 Kent, CT14 0JL UK
--BXVAT5kNtrzKuDFl
Content-Type: application/pgp-signature
Content-Disposition: inline
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.4.0 (FreeBSD)
iQCVAwUBQe0HnJr7OpndfbmCAQIXtwQA2ug6co4ATkcRXXj+1zI/kpE17/XFTnuN
28jEyBdSWUWU3zW6z+mfe9Z4GsYyV12lhBo1mREDtJowNxMZbmNIgECeR3ZVDHqV
6T26zFCyVqMsIr9pxLgzqEyE/SxpuP0NntWpiGgiBr6XY3YVZ13f63OcZz2qDdo4
iW982Y1GLC8=
=jd7G
-----END PGP SIGNATURE-----
--BXVAT5kNtrzKuDFl--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20050118125700.GA72972>