On 07/01/2013 10:55 PM, Jörn Engel wrote: > On Mon, 1 July 2013 19:23:25 +0000, James Bottomley wrote: >> On Mon, 2013-07-01 at 13:44 -0400, Jörn Engel wrote: >>> If a single device is bad, don't ever do a host >>> reset. >> >> This isn't a tenable position. Sometimes a device looks bad because the >> host state for it has gone insane. At that point, the only safe action >> is a reset of the host to sane state. >> >> I could be persuaded that you should never do the transport equivalent >> of a bus reset (on non-SPI transports, at least), which is actually hard >> to do on some of the modern transports, but I don't think you can get >> away without having a host reset in the eh arsenal. > > Fair enough. Hardware being hardware and hardware bugs being hard to > fix, I see your point. > > However, we shouldn't screw the poor user who has paid a premium for a > second HBA to get some redundancy and reset both of them at the same > time. That would, you know, defeat the redundancy. ;) > Which would arguably a setup issue. We've had SAN issues where the HBA lost track of the remote port state (RSCNs being eaten by the switch firmware), so the only chance of recovery was indeed a host reset. Cheers, Hannes -- Dr. Hannes Reinecke zSeries & Storage hare@xxxxxxx +49 911 74053 688 SUSE LINUX Products GmbH, Maxfeldstr. 5, 90409 Nürnberg GF: J. Hawn, J. Guild, F. Imendörffer, HRB 16746 (AG Nürnberg) -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
