RE: Solid State Drives
- From: "Tanel Poder" <tanel@xxxxxxxxxx>
- To: <dofreeman@xxxxxxxxxxx>, "'Oracle-L'" <oracle-l@xxxxxxxxxxxxx>
- Date: Fri, 1 May 2009 19:21:52 +0200
Once they get cheap and big then there would be a business case for them for
regular shops.
But right now, if you want to reduce the time spent waiting for physical
reads in your database - one way is buy faster IO subsystem which SSD may
give, another way is to just buy more memory for your server and do less
physical reads. The same is with writes, consider whether its cheaper to
buy/deploy/maintain the SSDs or just to have more write cache in your
storage array (and again, if you buy more RAM into your server for caching
read data then you can allocate even more of the storage cache for caching
writes).
So the question should be what's the most cost-effective option for
achieving the result - reducing TIME spent doing physical IO. Given the
write-caching of large storage arrays already in use in todays enterprises I
don't think adding SSDs make sense from cost/performance perspective. Of
course when the technology gets cheaper then the potential power savings and
lesser drive dying rate will be another factor to consider.
So my prediction is that, unless some other major new technology emerges in
coming few years, SSDs will replace disk spindles for online "active" data
just like (remote) disk spindles have replaced tape backups in some
enterprises (btw I'm not saying that I like this approach entirely - tapes
have the benefit of being physically disconnected from any servers, in a
guarded safe in a bank in another city or so).
In addition to backups, the disk spindles will still be used for archived
data as well (lots of storage which is rarely accessed), they are faster
than tape but cheaper per gigabyte than SSDs. Long term backups are kept on
tapes, but some companies will completely throw away their tape systems to
cut costs & complexity and keep all backups on disk spindles.
After saying all that - currently I don't see much reason for buying SSDs
for database solutions which are already deployed on mid/high-end storage
arrays.
--
Regards,
Tanel Poder
<http://blog.tanelpoder.com/> http://blog.tanelpoder.com
_____
From: oracle-l-bounce@xxxxxxxxxxxxx [mailto:oracle-l-bounce@xxxxxxxxxxxxx]
On Behalf Of Freeman, Donald
Sent: 01 May 2009 16:09
To: Oracle-L (oracle-l@xxxxxxxxxxxxx)
Subject: Solid State Drives
Has anybody given any thought to where we are going as SSD's get cheaper and
bigger? We've been going round and round at my shop with discussions about
RAID, other disk allocation issues, fights over storage. I mean we seem to
spend a lot of time on that issue. I saw that IBM is testing a 4 TB SSD. I
was wondering if you'd have to mirror that, What kind of reliability we
would be getting. No more RAID discussions? I've heard there is a finite
number of times you can write to it. What's the upgrade path here?
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