Re: IDEA - put redo logs onto a non-volatile RAM DISK?

From: Andrew Mobbs <andrewm_at_chiark.greenend.org.uk>
Date: 29 May 2001 10:50:57 +0100 (BST)
Message-ID: <HGj*aXnXo@news.chiark.greenend.org.uk>

Mark Tompkins <mdtompkins_at_home.com> wrote:
>Hi,
>
>Has anyone ever tried this? If so, why is it a bad idea?

I've put redo logs on battery-backed mirrored RAM in the cache of a large disk array, not writing to disk, and using that bit of RAM as a storage medium, not as cache. The vendor assured me that this was a supported configuration.

In the end I had to move them because they were filling up too quickly, and log switch checkpoints hurt. However, until then they performed extremely well.

I wouldn't trust a single RAM device with redo logs, just as with redo on normal disks, either use a mirrored storage or redo log groups.

-- 
Andrew Mobbs - http://www.chiark.greenend.org.uk/~andrewm/

Received on Tue May 29 2001 - 04:50:57 CDT