The short answer is, yes, they can span midnight. Very common.
The long answer.....
<TUTORING CAP>
What you need to be clear on is how the schedule 'windowing' works. When
you set up a schedule, you don't define how long the backup runs, you define
how long the startup window is. The startup window is the time in which the
schedule is allowed to start. Once the schedule has successfully started,
it will run as long as it needs to, there's no real limit there.
For example, if you set a schedule to start at 9:00 pm and give it a two
hour duration for the startup window, then the node has until 11pm to start
it's backup. If the node is able to start it's backup before 11pm, then
it'll run until it completes, however many hours it takes. If the node
can't start it's schedule for some reason until, say, 11:05pm, then one of
two things will happen:
1) If the node is set to SCHEDMODE PROMPTED (preferred), the server will
stop attempting to contact the node at 11:00 and announce that the node
missed it's window, or
2) If the node is set to SCHEDMODE POLLED (not preferred), when the node
contacts the server at 11:05, the server will deny the request and say it's
missed it's window.
Note that if you don't have a SCHEDMODE line in your options file, it will
default to POLLED mode.
Just to make things a little more long winded, there are two other factors
to consider that will affect the starting time of your backups.
Randomization - If you have several nodes associated with the same
schedule, ADSM is designed to randomize the start times of these nodes so
they don't all hammer the server at the same instant. The default is 25% of
the startup window, so in the example above, the nodes would theoretically
be told to start anywhere between 9:00 pm and 9:30 pm. In practice the
nodes all pretty much seem to start within a few seconds of each other
anyways, so I've never found this particularly useful.
MAXSESSIONS and MAXSCHEDSESSIONS - MAXSESSIONS defines the maximun number
of client sessions that can attach to the server at one time. This is
defined in the dsmserv.opt file (you must restart the server after editing
the file). If the maximum number of clients are already attached to the
server, any extra nodes will have to wait until a session becomes available,
and if no slot becomes available until after the schedule's window has
passed, then the node won't be allowed to start. MAXSCHEDSESSIONS is set
from within ADSM and is expressed as a precentage of MAXSESSIONS. if it's
set to 60% and maxsessions is at 25, then out of the 25 available sessions,
only 15 of them can be scheduled ones. If more than 15 scheduled sessions
try to connect, the extras will be denied until one becomes available.
Again, if one isn't available until the window passes, then it won't be
allowed to start it's backup.
So, to make a short story long, check that you don't have more schedules
running than maxsesssions and maxschedsessions allows, increase these
numbers if it's viable, otherwise rearrange your schedules. If your nodes
are just missing their windows, try increasing the duration of the window a
bit. Also, unless you have a specific reason to have the schedmode in
polled mode, set them to prompted so that the server contacts the client.
This will allow for more accuracy in the scheduling since by default a
client in polled mode only checks the server once every 12 hours to see what
it's schedule should be....
</TUTORING CAP>
later,
Paul
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