solaris/ZFSPoolActivationI written at 02:30:11; Add Comment
What I know about boot time ZFS pool activation (part I)
In response to my entry on the boot time ZFS and iSCSI sequencing bug, a commentator asked if SMF dependencies could be used to work around the issue. As it happens, this is not a simple question to answer because how ZFS pools are activated at boot time is at best an obscure thing (at least as far as I can tell). Here's what I think is going on, which has to come with a lot of disclaimers.
ZFS pool information for pools that will be imported during boot
(ZFS pool activation is, or at least seems to be, when the kernel tries to find all of the pool's devices and either finds enough of them to start the pool up or marks it as failed. Thus ZFS pool activation is the point at which all devices need to have been brought up.)
It's not clear to me when and how ZFS pools are actually activated. At
a low level pools seem to be activated on demand when they are
looked at. However there is no high level SMF service that says
'activate ZFS pools'; instead, they seem to get activated as a side
effect of other SMF services. I suspect that the primary path to
ZFS pool activation is the '
How iSCSI comes into this picture is sufficiently complicated that it needs another entry.
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