Date: Sun, 1 Feb 1998 16:41:17 +0300 (MSK) From: bag@sinbin.demos.su (Alex G. Bulushev) To: karl@mcs.net (Karl Denninger) Cc: current@FreeBSD.ORG Subject: Re: RAID controllers - folks, check this thing out Message-ID: <199802011341.QAA15231@sinbin.demos.su> In-Reply-To: <19980130233604.57426@mcs.net> from "Karl Denninger" at "Jan 30, 98 11:36:04 pm"
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> Remember a bit ago I was asking about RAID controllers? > > 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). we use INFORTRAND scsi-scsi RAID's (www.infortrand.com) cache up to 128MB (2 SIMM) 6 ultra-wide channels (3 chanels - base and 3 - extension board) backup battery for cache (up to 100h) serial interface (ansi, vt100 terminal) cpu 486dx2-66 (model with P5 is also available) up to 64 logical drivers (up to 8 raids, up-to 8 partition each) accordin to Justin T. Gibbs nonCAM distributions have problem with multiple LUN's Justin T. Gibbs: "Yes, this is a long standing bug having to do with multi-lun devices in the aic7xxx driver. It has been corrected in the CAM version of the driver, but the changes are too invasive to attempt to port them into the driver in either current or stable. Since this kinds of devices that trigger this problem are rare, it seldom causes problems. Yours is the first bug report I've seen about this issue." without CAM you can only use one logical drive per host channel Alex. > > 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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