Date: Fri, 18 Jun 1999 16:11:11 -0400 From: "David E. Cross" <crossd@cs.rpi.edu> To: Greg Lehey <grog@lemis.com> Cc: "David E. Cross" <crossd@cs.rpi.edu>, freebsd-hackers@FreeBSD.ORG, crossd@cs.rpi.edu Subject: Re: vinum performance Message-ID: <199906182011.QAA52485@cs.rpi.edu> In-Reply-To: Message from Greg Lehey <grog@lemis.com> of "Thu, 17 Jun 1999 17:47:47 %2B0930." <19990617174746.N9893@freebie.lemis.com>
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> > I have a drive that is rated at ~16 Meg/second, and indeed it delivers on the > > order of 15+ Meg/second. If I use Vinum to create a concatinated device > > of 2 such units performance drops to 2.5 Meg/sec. This seems like a > > drastic drop in performance. > > Indeed, if you're comparing apples with apples. > > > Any ideas what I am doin incorrectly? > > No. You haven't really given any details. > > Most of the performance testing I have done has been with striped > plexes (which offer the potential for better performance), and I've > found that in massively concurrent situations the performance is > roughly what you would expect (almost n * normal disk performance, > where n is the number of disks in the stripe set. I'd expect > performance of a concatenated plex to be pretty close to that of the > raw disk. How are you measuring performance? I'd recommend rawio > (ftp://ftp.lemis.com/pub/rawio.tar.gz). Ok, I am terribly sorry I didn't provide more information. I was very tired (it has been a long week; after the NFS work the main NFS server that has been having all of the problems decided that its main OS partion was going to have a hardware failure...) Anyway, here is some more information... bash-2.03$ df Filesystem 1K-blocks Used Avail Capacity Mounted on /dev/da0s1a 99183 21526 69723 24% / /dev/da0s1e 2032623 1062270 807744 57% /usr /dev/da0s1f 198399 3466 179062 2% /var /dev/vinum/concat 29077993 252757 26498997 1% /mnt bash-2.03$ cd /var/tmp bash-2.03$ df -k . Filesystem 1K-blocks Used Avail Capacity Mounted on /dev/da0s1f 198399 3466 179062 2% /var bash-2.03$ dd bs=64k if=/dev/zero of=foo count=2048 2048+0 records in 2048+0 records out 134217728 bytes transferred in 10.218804 secs (13134387 bytes/sec) bash-2.03$ cd /mnt bash-2.03$ df -k . Filesystem 1K-blocks Used Avail Capacity Mounted on /dev/vinum/concat 29077993 252757 26498997 1% /mnt bash-2.03$ dd bs=64k if=/dev/zero of=foo count=2048 2048+0 records in 2048+0 records out 134217728 bytes transferred in 59.653922 secs (2249940 bytes/sec) bash-2.03$ vinum info Can't open history file /var/tmp/vinum_history: Permission denied (13) Can't open /dev/vinum/Control: Permission denied bash-2.03$ su - hostname# vinum info Flags: 0x80204 Total of 21 blocks malloced, total memory: 9552 Maximum allocs: 1264, malloc table at 0xc3583ad4 hostname# vinum printconfig # Vinum configuration of hostname, saved at Fri Jun 18 16:08:56 1999 drive drive1 device /dev/da0s1h drive drive2 device /dev/da1s1h volume concat plex name concat.p0 org concat vol concat sd name concat.p0.s0 drive drive1 plex concat.p0 len 27597000b driveoffset 265b plexoffset 0b sd name concat.p0.s1 drive drive2 plex concat.p0 len 32405704b driveoffset 265b plexoffset 27597000b If you need anything else it can probably be provided. Oh, this is 3.2-STABLE from last week. -- David Cross | email: crossd@cs.rpi.edu Systems Administrator/Research Programmer | Web: http://www.cs.rpi.edu/~crossd Rensselaer Polytechnic Institute, | Ph: 518.276.2860 Department of Computer Science | Fax: 518.276.4033 I speak only for myself. | WinNT:Linux::Linux:FreeBSD To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
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