In article <[log in to unmask]>,
John Dunlop <[log in to unmask]> wrote:
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>
>
>On 1/3/96, Denysb @ AOL.COM (Denys Beauchemin) wrote :
>
>>2- Better resiliency. If you have multiple UVS (User Volume Sets) you are
>>less hurt when you throw a disc (so to speak). If the disc is part of SVS
>>(MPE_XL_SYSTEM_VOLUME_SET) you may be faced with an INSTALL but only for that
>>(relatively) small volume set. If the disc is part of a UVS, then only that
>>volume set goes down, the rest stays up. You can then deal with that UVS
> ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
>>while the other UVS' remain unaffected.
>
>I beg to differ, I have experienced situations where a Private Volume drive
>has failed and brought down the whole system. Also, the whole system has been
>brought down by merely attempting to purge a corrupt file on a PVS.
>
>Just to clarify.
>
>Cheers,
>John Dunlop ([log in to unmask])
Just a couple of thoughts about this thread.
First, if I remember correctly, HP tried to get people to forget about how
badly
private volumes worked on MPE/V by renaming them to Non-System Domain Volume
Sets on MPE/XL. The name never really stuck, so that today most HP people
speak
of private volumes and not non-system domain volumes.
Secondly, the main purpose of private volumes is to protect user data. Some HP
reps are misinformed and will tell you that private volumes will significantly
improve your uptime by eliminating downtime due to disk failures. This is not
true since the HP/3000 will allow users to continue to hold critical system
resources while they are waiting for a volume set to go back on-line. And as
long as they hold these critical resources (e.g. the file integrity SIR or even
a simple database lock) other users will continue to hang behind them. Also,
remember that while these users hold critical resources, they are also
unabortable.
I would like to also say, that as long as you use private volumes for data
protection, you will not be disappointed. Just don't try to use private
volumes
to increase your uptime, you will be disappointed.
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Michael P. Smith [log in to unmask]
HP Sr. Systems Programmer [log in to unmask]
Hertz Corporation, Oklahoma City, OK
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Manager: My boss says we need some eunuch programmers
Dilbert: I think he means UNIX and I already know UNIX.
Manager: If the company nurse drops by, tell her I said 'Never mind.'
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The views and opinions expressed in this document are expressly
my own. So get off the couch, I obviously need more help than you.
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