LARGE single-system Cyrus installs?

[Rob Mueller]

> The iostat and sar data disagrees with it being an I/O issue.
>
> 16 gigs of RAM with about 4-6 of it being used for Cyrus
> leaves plenty for ZFS caching.  Our hardware seemed more than
> adequate to anyone we described it to.
>
> Yes beyond that it's anyone guess.

If it wasn't IO limit related, and it wasn't CPU limit related, then there 
must be some other single resource that things were contending for.

My only guess then is it's some global kernel lock or the like.

When the load skyrocketed, it must have shown that lots of processes were 
not in S (sleep) state. Were they in R (run) state or D (io wait) state? 
Since you're on Solaris, you could use DTrace to find out what they were 
actually doing/waiting for...

Rob