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Re: The old raw devices chestnut.

From: Paul Watson <>
Date: Wed, 14 Apr 2004 01:48:59 +0100
Message-ID: <>

Andrew Hamm wrote:
> Mark Bole wrote:
> > I haven't worked with an Oracle raw device since version 7.3 seven
> > years ago, and would never go back. The administrative overhead is
> > just too much of a headache.
> [Posting from comp.databases.informix]
> I've never understood the "administrative overhead" argument against raw
> spaces. Can you elicidate on the administration you think needs to be
> applied? In my experience, the only admin overhead is making sure that a
> new, naive sysop doesn't try to turn a raw space into a filesystem - I saved
> an engine by SECONDS once, by looking over the shoulder of said sysop as I
> walked past....
> Apart from that, I find that admin is slightly simpler simply because you
> don't need to run a mkfs style of command ;-)
> I have heard that Solaris (?) is in the habit of re-creating /dev at boot
> time, and I know that DG-UX used to do the same thing. Therefore some sort
> of tool is needed to make sure the raw devs exist after a boot. Is this what
> you mean?

This should only happen with a boot -r, Sun doesn't (used to) guarantee the
mapping of mulitple external physical devices (A5200, A1000 etc) is consistent
when boot -r'ing. The 'boot -r' asks what's out there and then assigns the
devices in the order in which they respond. Mostly it catches lazy sysadmins,
or sysadmins without larger server experience out. When the disks are used
with filesystems AFAIK Sun can map the FS back to the disks, I'm guessing
they use major/minor numbers. Solaris can't do this with the raw disk 'cos Solaris has no idea how they are being used.

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Received on Tue Apr 13 2004 - 19:48:59 CDT

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