[CentOS] Symantec ghost and CentOS 3.4/4.0

Bill Maltby wild-bill at triad.rr.com
Tue Oct 4 16:54:02 UTC 2005

>Message: 28
>Date: Mon, 03 Oct 2005 11:22:40 -0500
>From: Les Mikesell <lesmikesell at gmail.com>
>Subject: Re: [CentOS] Symantec ghost and CentOS 3.4/4.0
>To: CentOS mailing list <centos at centos.org>
>Message-ID: <1128356560.29433.17.camel at moola.futuresource.com>
>Content-Type: text/plain
>On Mon, 2005-10-03 at 11:06, Ted Kaczmarek wrote:
>Or, if the machines are close to identical including the drives, just
>use dd to copy the whole disk.  It's slow in real-time but takes very
>little human time.
With proper use of the bs= parameter to dd, it can be very fast. Just 
need to watch out that the jobs the node is doing at that time are not 
unacceptably degraded, since we don't have a preemptive scheduler (? I 
think... haven't been paying atention the last year or so.) yet.

Using a blockisize that takes advantage of cache sizes (several levels 
of these) would be optimal, but the 80/20 rule seems to apply here. So I 
always just use a block size that is a cylinder (not really a cyl, but 
who knows what they really are these days?) based on the HD parameters. 
What's really important is not the size, but the reduction in number of 
system calls.

Anyway, not a major issue, but since I luv dd (and ed and other old time 
real *IX stuff) I didn't want it to get a bad rap!  ;)

> -- Les Mikesell lesmikesell at gmail.com

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