Re: Swap over network ;The Doctor What ("
Thu, 01 May 1997 14:45:38 -0700

Telephone Game! John Wyszynski said (on 09:35 PM 4/30/97 -0400):
-> (Harald Milz):
->> BTW Striping across machines is probably not very useful. If one machine
->> fails, data is completely lost.

->That is the potential flaw with stripping regardless; the fact that
->machines are involved has no effect in this as only disk drive
failures result
->in data lost. The whole point of stripping is to boost performance
at the
->price of reliability. Spreading it across a LAN could be a big win for an
->I/O intensive application.

You can "combine" striping and mirroring to get improved performance
and safety.

I've forgotten the specifics, but I remember learning about it at the
same time as I learned about striping/raid storage for hard disks (I'm
sure this'll work for networked drives).

The idea was that you can use parity or checksuming on one of the
"disks". If you loose only one machine, then you can recover with the
information on the others. You need a more complicated checksum/parity
routine if you want to be able to loose more than one machine at a time.

Hence, you can control the amount of "safety" or reliability you have,
while being able to get decent speed.

I can look the specifics up, if anyone wants it.

The Doctor What: Guru of the Gods                     (finger for PGP key)
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