From mboxrd@z Thu Jan 1 00:00:00 1970 From: Asdo Subject: Re: Typical RAID5 transfer speeds Date: Mon, 21 Dec 2009 12:30:34 +0100 Message-ID: <4B2F5C5A.7070702@shiftmail.org> References: <4B2D4731.3090702@gmail.com> <4877c76c0912192021s2c3da63au57f5dcb0391b3eb3@mail.gmail.com> <4B2E6CDB.3000707@gmail.com> <4877c76c0912201718l6d7ab948q4c57a07109678cb5@mail.gmail.com> <4B2ED47C.7010307@sauce.co.nz> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-reply-to: <4B2ED47C.7010307@sauce.co.nz> Sender: linux-raid-owner@vger.kernel.org To: Richard Scobie Cc: Michael Evans , Roger Heflin , Matt Tehonica , linux-raid@vger.kernel.org List-Id: linux-raid.ids Richard Scobie wrote: > Or use dumb LSI SAS controllers (sas3442e-r with IT firmware loaded, > $200) and port expander based chassis that allow considerable > flexibility regarding md RAID and number of SAS/SATA drives attached. The problem then becomes choosing the port expander chassis... I know nothing about this topic :-( Does the brand/model make difference in performance or reliability? Do you have any recommendation? Even just one "known good"... (These chassis are also quite expensive for what I can see.) Up to 24 and maybe even 48 drives you can find monolithic solutions (one chassis for mainboard and disks), but then not many brands make 16-24 ports controllers. LSI does not seem to make them, am I correct? Also in a monolithic storage you only have to check that the controller declares compatibility with the drives (sometimes there are indeed issues) while for port-replicator based storage I don't know if I should check the Compatibility List for drives against controllers, or for drives against port replicator, or for controller against port replicator...?