[OpenIndiana-discuss] why zpool import cost a long time or hung?

[Jim Klimov]

On 2014-06-10 05:27, Dang Zhiqiang wrote:
> Hi,
> I want to know why zpool import cost a long time or hung? and how to fix it?
> thanks.

It might take some time to "think", in particular about delayed
operations (i.e. large dataset deletions which were just marked
as deleted, and then lots of metadata has to be raked through
to actually free up the space - especially lots of work for some
deduped datasets); this can be somewhat tracked by "zdb -bbLC pool"
or somesuch (takes a minute to get the metadata) - see the progress
and (non-zero-ness at all) of "Deferred free" and similar entries.

Some more info can be gleaned with "iostat" to see if any disk io
occurs (maybe lots of random slow ios).

HTH,
//Jim