Date: Fri, 21 Sep 2007 12:49:28 +0200 From: Ivan Voras <ivoras@freebsd.org> To: freebsd-fs@freebsd.org Subject: Re: Writing contigiously to UFS2? Message-ID: <fd07jr$gp9$1@sea.gmane.org> In-Reply-To: <46F24F2C.40205@fluffles.net> References: <46F24F2C.40205@fluffles.net>
next in thread | previous in thread | raw e-mail | index | archive | help
This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --------------enig5CF3686197E6B1275D584F4E Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: quoted-printable Fluffles wrote: > Hello list, >=20 > I've setup a concat of 8 disks for my new NAS, using ataidle to spindow= n=20 > the disks not needed. This allows me to save power and noise/heat by=20 > running only the drives that are actually in use. >=20 > My problem is UFS. UFS2 seems to write to 4 disks, even though all the = There 4 drives are used in what RAID form? If it's RAID0/stripe, you=20 can't avoid data being spread across the drives (since this is the point = of having RAID0). > data written so far can easily fit on just one disk. What's going on=20 > here? I looked at newfs parameters, but in the past was unable to make = > newfs write contigiously. It seems UFS2 always writes to a new cylinder= =2E=20 > Is there any way to force UFS to write contigiously? Or at least limit = > the problem? If the drives are simply concatenated, then there might be weird=20 behaviour in choosing what cylinder groups to allocate for files. UFS=20 forces big files to be spread across cylinder groups so that no large=20 file fills entire cgs. --------------enig5CF3686197E6B1275D584F4E Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.5 (GNU/Linux) Comment: Using GnuPG with SUSE - http://enigmail.mozdev.org iD8DBQFG86G5ldnAQVacBcgRA5udAJ9L3OmCHFrUOawWoO7KtdoDM2OSQQCgi1xG 8r9XI/M4ebP4xNTsmbXKSKk= =18nj -----END PGP SIGNATURE----- --------------enig5CF3686197E6B1275D584F4E--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?fd07jr$gp9$1>