Date: Mon, 2 Feb 1998 15:11:01 -0800 (PST) From: karl@mcs.net To: undisclosed-recipients:; Message-ID: <199802022311.PAA02473@hub.freebsd.org>
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Well, I found one. Talk to Pacific Computer Expansions, a gentleman by the name of Warren at 800-458-5058. You want the CRD-5440. This is a RAID 0, 0+1, 4 or 5 free-standing SCSI device. It accepts cache memory, and also has battery backup capabilities (attach a 6V Gelcel to it). I have MEASURED *filesystem* I/O rates in excess of 10MB (yes, that is megaBYTES/second) through this thing on a 5-disk array running RAID 5 doing *WRITES*. RAW I/O is considerably faster, as you might expect, and reads are even faster. Reads appear to be limted by the Ultra SCSI interface. This thing has 4 SCSI channels; any number can be delegated to disk and/or host use. Its ultra/wide, and comes in both a differential and single-ended version. Fits in a half-height drive bay (!), powered by a 40Mhz MIPS R3000 processor. It accepts one or two 72-pin SIMMs with up to 512MB (!) of cache memory; the cache, needless to say, grossly improves the performance, especially in a read-intensive environment. It has both a front panel and serial interface (you need to hook up a terminal to configure it, but alarm reporting and rebuild control can be done from the front panel). One catch - you MUST HAVE either a UPS interfaced to this, or a gelcell. The reason is the cache RAM - without one of those two it will refuse to go "online", because a power loss will screw you badly. With the UPS interfaced to it the "low power alarm" will quiesce the host channel and flush the cache, then shut down the controller - leading to a safe power-down. If you have the battery, then a power loss is also not catastrophic (as long as the backup lasts at least). The controller can handle up to 45 devices (!) in multiple RAID sets, appears as a single target per host channel, and can be partitioned to show multiple LUNs if you'd like. Both hot and warm spare capabilities are supported. FreeBSD will boot from it just like any other disk. Right now I have a ~30GB "disk" configured on this thing - 5 9G drives in a Raid 5 configuration. It works right out of the box. Its about a $2500 device, but given what it does, and the performance levels it attains, its VERY reasonable. I'm ordering six more of these for our server farm next week; for the money its basically impossible to beat the performance and operational capabilities, at least from what I've seen so far. In the area of "small" RAID adapters I've not seen anything that can come anywhere close to this thing's performance levels. -- -- Karl Denninger (karl@MCS.Net)| MCSNet - Serving Chicagoland and Wisconsin http://www.mcs.net/ | T1's from $600 monthly to FULL DS-3 Service | NEW! K56Flex support on ALL modems Voice: [+1 312 803-MCS1 x219]| EXCLUSIVE NEW FEATURE ON ALL PERSONAL ACCOUNTS Fax: [+1 312 803-4929] | *SPAMBLOCK* Technology now included at no cost
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