Date: Tue, 20 Sep 2011 11:01:05 -0500 (CDT) From: Bob Friesenhahn <bfriesen@simple.dallas.tx.us> To: Freddie Cash <fjwcash@gmail.com> Cc: freebsd-fs@freebsd.org Subject: Re: ZFS obn FreeBSD hardware model for 48 or 96 sata3 paths... Message-ID: <alpine.GSO.2.01.1109201055160.26410@freddy.simplesystems.org> In-Reply-To: <CAOjFWZ5YG5raCwvE-kZQ9wjzYvxqCRBPFy47FWOsN1Yjoga1Bw@mail.gmail.com> References: <alpine.GSO.2.01.1109171451500.1973@freddy.simplesystems.org> <1316459220.35419.YahooMailClassic@web121209.mail.ne1.yahoo.com> <CAOjFWZ6Y4PbAaZzMxyzZHmtrNBJzOK8GMVJL0GP0PMdwj9SeXg@mail.gmail.com> <alpine.GSO.2.01.1109191613520.7097@freddy.simplesystems.org> <CAOjFWZ5YG5raCwvE-kZQ9wjzYvxqCRBPFy47FWOsN1Yjoga1Bw@mail.gmail.com>
next in thread | previous in thread | raw e-mail | index | archive | help
This message is in MIME format. The first part should be readable text, while the remaining parts are likely unreadable without MIME-aware tools. ---559023410-351212254-1316534465=:26410 Content-Type: TEXT/PLAIN; charset=UTF-8; format=flowed Content-Transfer-Encoding: 8BIT On Mon, 19 Sep 2011, Freddie Cash wrote: > > L2ARC has extreme bandwidth limitations as compared with RAM. Be careful what you wish for. > > For writes (7 MBps, I believe); there shouldn't be any limits on the reads. If (for example) an SSD is used with a 200MB/s read rate for the L2ARC, then the L2ARC is limited to 200MB/s (as compared with perhaps 10GB/s or 20GB/s for RAM). The L2ARC is really all about eliminating the access latency of rotating-rust but any device will provide far less bandwidth than system RAM. Bob -- Bob Friesenhahn bfriesen@simple.dallas.tx.us, http://www.simplesystems.org/users/bfriesen/ GraphicsMagick Maintainer, http://www.GraphicsMagick.org/ ---559023410-351212254-1316534465=:26410--
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?alpine.GSO.2.01.1109201055160.26410>