Re: How to hot swap an SCA SCSI disk with NetBSD
> Generally speaking, SCA SCSI drives are hot-swap capable. Sure...but the drive bays aren't necessarily. For example, the drive bay in a SS20 probably isn't; you can't even get to it without removing the lid, so there'd've been little reason for Sun to spend the money for the signal switching hardware to make it hotswap. > I'm not interested in fiddling with 50-pin or 68-pin with a paused machine -$ Actually, with a _paused_ machine, IME - I M limited E - it's fine. It's doing so on an active SCSI bus, one with transfers going on, that I was saying was a recipe for trouble. > The key thing in documentation is not just how, but why. > For example, why "scsictl detach"? Why not just "stop" and > remove? Personally? The reasons which occur to me offhand: Because doing that doesn't get the teardown and rebuild I mentioned upthread. Because not all the scsictl versions I have in use support stop. Beacuse I'm not always replacing it with an identical drive (or, sometimes, at all). > The idea here is to document a procedure generally. Odds are good lots of it$ Yeah - everything but the physical-layer stuff, I'd guess. (SAS, gh) /~\ The ASCII Mouse \ / Ribbon Campaign X Against HTMLmo...@rodents-montreal.org / \ Email! 7D C8 61 52 5D E7 2D 39 4E F1 31 3E E8 B3 27 4B
Re: How to hot swap an SCA SCSI disk with NetBSD
On Fri, Oct 25, 2013 at 01:43:28AM -0700, Erik Fair wrote: > Generally speaking, SCA SCSI drives are hot-swap capable. > > I'm not interested in fiddling with 50-pin or 68-pin with a paused machine - > that's (as you note) a recipe for errors and filesystem corruption. > > The key thing in documentation is not just how, but why. > > For example, why "scsictl detach"? Why not just "stop" and remove? If you swap in an identical drive, detach/scan is not needed. If the drive you swap in is different, you need the detach/scan so that the kenrel is forced to send an INDENTIFY to the drive to get new parameters. -- Manuel Bouyer NetBSD: 26 ans d'experience feront toujours la difference --
Re: How to hot swap an SCA SCSI disk with NetBSD
Generally speaking, SCA SCSI drives are hot-swap capable. I'm not interested in fiddling with 50-pin or 68-pin with a paused machine - that's (as you note) a recipe for errors and filesystem corruption. The key thing in documentation is not just how, but why. For example, why "scsictl detach"? Why not just "stop" and remove? The idea here is to document a procedure generally. Odds are good lots of it would apply to SAS drives, too. Erik
