A while ago Tom's hardware did a series in a solar powered PC... many of the power saving decisions sound relevant to your requirements. The article is still available at http://www.tomshardware.com/reviews/hardware-components,1685.html
Hmmmm - so a programme has gathered email addresses from web pages, and sent inappropriate messages to them. That sounds like spam to me... just report it to the BSAs ISP - they may be violating the terms of their service agreement:-)
Sharing discs on a SCSI bus between machines is quite possible - I have done it on both Sun/sparc & Linux/x86 machines. There are a number of things to watch out for when trying to do this...
A SCSI bus is just that - a bus, which needs to be terminated at both ends. Each device on the bus must have a separate address. This includes the controller board - sometimes called the SCSI initiator. As supplied by the manufacturer a controller will normally be set to the highest numbered address on the bus - 7 for a narrow (8 bit) bus, 15 for a wide (16 bit) bus. When connecting two controllers to one bus, you must change the address of one of the controllers.
Things to check include:
Can the initiator ID be changed on the controllers you are using (it can on the Adaptec 2940, I don't know about other boards).
Can the controller & device driver cope with unexpected events on the bus ? eg. if one machine does a bus reset (perhaps during a reboot), does the other machine carry on ?
Are both ends of the bus properly terminated ? If one machine is powered off, will it fail to correctly terminate it's end of the bus ?
It is possible for both machines to access the disc, and indeed having different partitions mounted on different machines will work, though throughput may be poor (think of what happens to the seek scheduling algorithms when another machine is also accessing the disc). I am not aware of any filesystem which will cope with two machines accessing it at the same time. Trying to do this is a great way to get a corrupt filesystem.
It is possible to unmount a filesystem from one machine, & then mount it on the other. When doing this be very careful that the disc & filesystem caching doesn't mess things up. It's not just a matter of flushing the write cache on unmount - a read cache which persists through unmount then mount will also cause problems. If this cached data is wrong because another machine has changed what is really on the disc, filesystem corruption can result - I have seen this happen.
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A while ago Tom's hardware did a series in a solar powered PC... many of the power saving decisions sound relevant to your requirements. The article is still available at http://www.tomshardware.com/reviews/hardware-components,1685.html
Hmmmm - so a programme has gathered email addresses from web pages, and sent inappropriate messages to them. That sounds like spam to me... just report it to the BSAs ISP - they may be violating the terms of their service agreement :-)
Cheers -- Dave.
Sharing discs on a SCSI bus between machines is quite possible - I
have done it on both Sun/sparc & Linux/x86 machines. There are a
number of things to watch out for when trying to do this...
A SCSI bus is just that - a bus, which needs to be terminated at both
ends. Each device on the bus must have a separate address. This
includes the controller board - sometimes called the SCSI initiator.
As supplied by the manufacturer a controller will normally be set to
the highest numbered address on the bus - 7 for a narrow (8 bit) bus,
15 for a wide (16 bit) bus. When connecting two controllers to one
bus, you must change the address of one of the controllers.
Things to check include:
Can the initiator ID be changed on the controllers you are using (it
can on the Adaptec 2940, I don't know about other boards).
Can the controller & device driver cope with unexpected events on the
bus ? eg. if one machine does a bus reset (perhaps during a reboot),
does the other machine carry on ?
Are both ends of the bus properly terminated ? If one machine is
powered off, will it fail to correctly terminate it's end of the bus ?
It is possible for both machines to access the disc, and indeed having
different partitions mounted on different machines will work, though
throughput may be poor (think of what happens to the seek scheduling
algorithms when another machine is also accessing the disc). I am not
aware of any filesystem which will cope with two machines accessing it
at the same time. Trying to do this is a great way to get a corrupt
filesystem.
It is possible to unmount a filesystem from one machine, & then mount
it on the other. When doing this be very careful that the disc &
filesystem caching doesn't mess things up. It's not just a matter of
flushing the write cache on unmount - a read cache which persists
through unmount then mount will also cause problems. If this cached
data is wrong because another machine has changed what is really on
the disc, filesystem corruption can result - I have seen this happen.
Good luck !