[Info-vax] Unpleasant Disk Shadowing Surprise

[Michael Moroney]

JF Mezei <jfmezei.spamnot at vaxination.ca> writes:

>Rob Brooks confirmed that they do go into mount verify, a process
>necessary to determine if the remaining members of the shadowset are
>trustable (aka: valid data etc) before resuming service.

>The question should really be: what could cause mount verification to
>last 3 minutes.  (perhaps both disks were inaccessible during that time).

If one drive goes offline, SHADOWING will try SHADOW_MBR_TIMEOUT (default
120 seconds) before giving up and booting the failed drive out of the
shadowset.  The OP didn't state what the value of SHADOW_MBR_TIMEOUT is.

If a drive fails and the OP wants the application to continue using the
reduced shadowset without intervention, he needs to set SHADOW_MBR_TIMEOUT
to be less than the maximum time they can tolerate to wait for the disk.
(SHADOW_SYS_TMO for the system disk shadowset)

-Mike
(ex-SHADOWING devo)