Re: Redo block size...

From: Andrey <adm_at_mlm.ru>
Date: Mon, 26 Jan 2004 12:58:09 +0300
Message-ID: <bv2oc8$s4l$1@gavrilo.mtu.ru>

"Noons" <wizofoz2k_at_yahoo.com.au> wrote in message news:401471f0$3$19709$afc38c87_at_news.optusnet.com.au...
> "Yong Huang" <yong321_at_yahoo.com> wrote in message
> news:b3cb12d6.0401251443.e217f7b_at_posting.google.com...
>
> > filesystem-based. In my case, it's using Veritas Quick I/O but
> > reported as raw.
>
> That would be because the partition is managed by Veritas itself
> from a Unix raw partition?
>
> > Most OSes use 512 bytes as logfile block size. But HPUX uses 1k,
> > probably DEV_BSIZE defined in /usr/include/sys/param.h. This size is
> > actually not filesystem dependent.
>
> Actually, if the redo log file is in a file system, write size is
> totally dependent on it. If you request a write of 512 bytes in
> a file system of 4K block size, the OS *will* write 4K.
> Like it or not...
>
> And the main reason for the usual recomendation to keep redo
> log in raw.

Excuse me Souto, I'm reading this conference for several years, and remember very good Sybrands indignation about someones placement redo logs on raw partitions.
I can dig some evidences if it is required.

> --
> Cheers
> Nuno Souto
> wizofoz2k_at_yahoo.com.au.nspam
>
Received on Mon Jan 26 2004 - 03:58:09 CST