Date: Mon, 8 Dec 2014 12:03:46 -0800 From: Tom Samplonius <tom@samplonius.org> To: patpro@patpro.net Cc: freebsd-scsi@freebsd.org Subject: Re: multipath problem: active provider chosen on passive FC path? Message-ID: <81548287-A118-4AFD-8AB5-F76CD3B060FF@samplonius.org> In-Reply-To: <23F06C2E-558A-4E68-AD35-B3CD49760DFE@patpro.net> References: <23F06C2E-558A-4E68-AD35-B3CD49760DFE@patpro.net>
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>=20 > I've installed FreeBSD 9.3 on two HP blade servers (G6), into an HP = C7000 chassis. This chassis uses two Brocade FC switches (active/passive = if I'm not mistaken). The blade servers use=20 > Unfortunately during boot, and during normal operation, the first = provider (da2 here) seems faulty: >=20 > isp0: Chan 0 Abort Cmd for N-Port 0x0008 @ Port 0x090a00 > (da2:isp0:0:2:0): Command Aborted > (da2:isp0:0:2:0): READ(6). CDB: 08 00 03 28 02 00=20 > (da2:isp0:0:2:0): CAM status: CCB request aborted by the host > (da2:isp0:0:2:0): Retrying command FC switches are typically active-active, as the FC switch fabric is = "intelligent" and doesn't have looping issues like ethernet. Your issue is probably on the storage array. Storage arrays typically = have an OS profile, and various advanced settings for how a LUN is = exported to a client. Storage arrays typically support SCSI = Reservations, where the LUN must be reserved before it can be used. = Also, storage arrays typically have multiple controller cards, and = typically an LUN is owned by one of the controllers at a time. The = storage array can signal to the client via SCSI that it wants to move = the the ownership to another controller. With proper client support, = migrating a LUN to another controller is typically hit-less.=20 In your case, the storage array is probably configured to use one = controller/path at a time. And it is probably expecting to see specific = SCSI messages between itself and the host. These type of settings are = typically set by the OS profile. Generally, storage arrays work best if you only send IO to one = controller at a time. And this involves co-ordination between the array = and the client using SCSI control messages. Though active-active paths = can usually be supported as well. Tom
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