Date: Thu, 09 Nov 2006 11:59:34 +0000 From: Pete French <petefrench@ticketswitch.com> To: ivoras@fer.hr Cc: freebsd-stable@freebsd.org Subject: Re: Dissapointing performance of ciss RAID 0+1 ? Message-ID: <E1Gi8ZC-000Dgf-QH@dilbert.firstcallgroup.co.uk> In-Reply-To: <455314B8.7080104@fer.hr>
next in thread | previous in thread | raw e-mail | index | archive | help
> > Raw dd gives 50 meg/second > On /dev/da1, with a reasonable block size (1m)? Block size is 2meg. I was using da1s1 and da1s2 which were giving me 50 and 47 meg/second resepctively - if I switch to da1 on it's own I get 59 meg/second. reading from the filesystem with the vfs.read_max set to 64 I now get 112 meg/second though ?!!! how can the filesystem give me better performance than the raw device ? I do not think this is a caching issue as I am using a test file nearly twice the size of the RAM in the system to get round this. I am delighted by the performance increase, but the results do not make sense. -pete.
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?E1Gi8ZC-000Dgf-QH>