Re: SSD usage

Few random thoughts on the topic:
1) SSD/flash world is growing and changing rapidly. Soon enough most storage is going to be in some form of flash 2) SSD/flash is perfect for random reads and not so good for continuous writes by design (search write cliff SSD). With your values for redo it most likely shouldn't be an issue 3) anything under few hundred MB of redo/sec can be served with reasonable latency by rotational disks provided you have a good write cache 4) log file sync waits are not only about writing redo, it's much more complex than that, especially with modern oracle releases. If you need better advice then you need to start with 1h statspack/awr report of your system
5) usually these days people use ASM and its striping for the best results from all available disks, and rarely spend time deciding how to assign parts of database to different drives.

On Wednesday, 16 December 2015, Storey, Robert (DCSO) < RStorey_at_dcso.nashville.org> wrote:

> Morning,
>
>
>
> I’ve been reading multiple docs on SSD/HDD and the benefits within an
> oracle database.
>
>
>
> If I am reading this write, for an OLTP system, the SSD/FLASH will provide
> excellent random read/write abilities.
>
>
>
> But folks seem contradicted on using the SSD for the Redo logs. Some say
> its best practice, others say it does not buy you anything.
>
>
>
> I have a 24/7 OLTP application that generates a modest amount of redo. My
> overall DB is about 95 gigs, I generate about 600megs of redo in a day
> (10meg files, switching every 30 or so). My system is getting to end of
> life, and I see more log_file_sync waits, and buffer busy waits. I suspect
> my I/O subsystems are getting worked hard. My top waits appear to be
> sequent file reads and scattered reads, log file sync, and buffer busy.
>
>
>
> What’s the general verdict on using SSD for the data files? Best idea
> for redos? My thoughts there are separating them to different drives, ie,
> two separate single disks, with a group member on each disk.
>
>
>
>
>
> Thoughts?
>
>
>
> Thanks
>

-- 
Regards
Timur Akhmadeev

--
http://www.freelists.org/webpage/oracle-l