Date: Wed, 12 Jan 2000 23:46:38 +0000 From: George Cox <gjvc@extremis.demon.co.uk> To: Sean Heber <sean@bebits.com> Cc: freebsd-questions@FreeBSD.ORG Subject: Re: Are huge file systems bad? Message-ID: <20000112234638.A376@extremis.demon.co.uk> In-Reply-To: <002d01bf5d43$845331e0$0a04cfd1@mwci.net>; from sean@bebits.com on Wed, Jan 12, 2000 at 03:25:13PM -0600 References: <002d01bf5d43$845331e0$0a04cfd1@mwci.net>
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On 12/01 15:25, Sean Heber wrote: > 1) Are huge file systems bad? No. They rule. There are some 'issues' with large filesystems. One is inode allocation. If a filesystem runs out of inodes you are stuffed -- the onlt thing you can do is back up the files somewhere else, create a new filesystem with more inodes that the previous one and restore. Very dull. One situation where this could happen is on large mail servers where each message takes a file in the filesystem. (EG: Maildir format) > I have concatenated two large drives together using vinum. The resulting > file system is 50Gig. Woo hoo! Vinum rules. Get your company to donate disks to Greg! :-) > 2) Is there another way to structure this that would keep file systems > small but be easy to manage if number 1 is bad? You should attempt to profile your filesystem usage -- high priority / high volume users and less active users maybe, and work from there. > Our structure for the ftp site has the ftp dir for each user under > /sites/ftp/usr. So like this: > > usr/bdev1 usr/bdev2 usr/bdev3 usr/bdev4 usr/bdev5 ... > > As far as I can tell, that makes it very hard to break up all the space > into smaller partitions. Hmmmm. See below > So that's why I went the vinum route. However, I've had conflicting > reports that large file systems can be really dangerous. So I'd like to > know for sure. 50GB could well be dangerous if dropped on you from a great height. :-) One thing to note is that FFS performs lookups in a directory in a linear fashion. (It keeps a cache to improve matters however). This is why putting all users home directories in one huuuge-ass directory is a bad idea. This is why you see large sites refer to files in this kind of way /u/h/he/heber Each level of the directory hierarchy has fewer entries so it can be traversed faster. best; gjvc -- [gjvc] 4.4BSD 4.ever! To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-questions" in the body of the message
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