Ignoring devices

[Dima Veselov <kab00m%lich.phys.spbu.ru@localhost>]

Greetings,

I have NetBSD system located on disk array, accessed via
Fibre Channel HBA, which is connected to FC-switch
There are other devices on this bus and some of the devices
are not accessible to the box. According to standard FC
behaviour HBA have all devices enumerated on the bus,
but can not read them.

This lead to messages log overfilled with records like
sd5d: error reading fsbn 4269797375 (sd5 bn 4269797375; cn 1042430 tn 63 
sn 63)

Is there any way to ignore certain devices, so the kernel won't
try to read from them?

I also discovered that happens daily, at 3:15 PM, so if there
is no way to ignore device - is there a way to stop daily(5) from
accessing unused devices?

--
Dima Veselov
Physics R&D Establishment of Saint-Petersburg University