Why is restore so slow?

Martin Weitzel martin at mwtech.UUCP
Thu Jan 31 22:54:29 AEST 1991


In article <19012 at rpp386.cactus.org> jfh at rpp386.cactus.org (John F Haugh II) writes:
:In article <1013 at eplunix.UUCP> das at eplunix.UUCP (David Steffens) writes:
:>Who cares how slow restore is?  How often do you do have to do
:>full restore on a filesystem or a whole disk?  Once or twice a year?
:>If it's more often than that, then you have a REAL problem
:>and maybe you ought to spend your time and energy fixing THAT!
:
:There are quite a few reasons in an EDP environment for restoring
:files.  For example, before a large unreversible process, it is
:common to dump the entire database partition so it can be restored
                                                    ^^^
:if the process is found to have completed incorrectly.  This is
:very common for such operations as payroll, monthly account closing,
:quarterly stuff, etc.

But you are talking about a dump here that can be restored. CAN be.
Not MUST be. Restoring the whole thing only becomes necessary IF
the process has completed incorrectly. If this gets the normal case
rather than the exeception, you were right, but then I dare to say the
software is seriously flawed, if some operation frequently completes
incorrectly.

One case where it is normal that some operation fails frequently
is during program development and testing. But then there should be
enough space to have several sets of test data on disk. Otherwise the
development system is badly choosen and you were better of to buy a
larger disk. Programmers are expensive. Their costs accumulate over
time. Buying some additional hardware costs only once! (Remembers me
of the time when I had to insert a special floppy if I wanted to copy
a file, since for this machine, a IBM 5110 single user BASIC-"PC", you
couldn't copy files with the builtin software. It was rather counter
productive, since the copy program used the same memory where the BASIC
source was and if you forgot to save the source, the work of the last
hours may have been gone :-().

:The answer to questions like "How often do you do X" often come
:down to "Often enough that we can't stand it any longer."

Sure, but in any case the question should be allowed: "Why have you to
do it so often?". What would you say if someone complained that
formatting and verifying a 380 MB disks takes him half a day and
that's simply too much time each the day? Wouldn't you ask him WHY
he is formatting the disk evey day?
-- 
Martin Weitzel, email: martin at mwtech.UUCP, voice: 49-(0)6151-6 56 83



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