Making a bootable backup (hard)disk... how?
Robert Huff
roberthuff at rcn.com
Mon Jun 11 00:15:54 UTC 2012
Ronald F. Guilmette writes:
> Warren? Just a couple more quick questions. You recommend:
>
> >> dump -C16 -b64 -0uanL -h0 -f - /usr | (cd /mnt && restore -ruf -)
>
> I'm real curious about you suggestions for the -C and -b values.
>
> I have what amounts to a personal workstation. Yea, OK, it is running
> mail, web, and FTP servers also, but fundementailly, it is not that busy
> most of the time. And it's got 4GB of main installed. On average, I
> suspect that I ain't even using half of that.
>
> Given all that, why shouldn't I specify (e.g.): -C512 -b1024 ?
>
> Wouldn't that all make the dump go faster?
There are many possible obstacles to faster dump speed;
enumerating them is left as an exercise for the reader.
As it happens, I have a set-up very similar to what you
describe ... except with 8g of memory. A few years ago I did some
testing with various cache sizes (as part of diagnosing other
problems) and ended up with C=32.
(I should probably run the tests again, given some hardware
changes since.)
That machine's level 0 runs tonight; I will try to remember to
(retain and) post the results.
Robert Huff
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