Hi Henrik,

Well as I was specing a new TSM server i thought, why not try for the best 
performance possible and although the SSD drives drives the server costs up by 
50% it wasn't out of the ballpark, therefore I wanted to hear from the 
community what their ideas were.

As it stands I have a 100GB DB currently ~50% used but according to IBM TSM 6.2 
will require double DB size hence 200GB and since we are expecting a 40% 
data-growth next year and will be implimenting Dedupe I thought why not see how 
the price/performance goes on other sites. 

As db2 is a fully featured DB I thought that the alternative would be to give 
it more RAM, as it's so much cheaper than SSD's.  And also how I could 
configure my DB2 to use the extra RAM that I will be throwing at it in any case.

With the current feedback I will be sticking to 6 x SAS 15K and 24GB RAM...

Please if there's any other opinions let's hear it, the more opinions the more 
wisdom...

Regards
Louw Pretorius

-----Original Message-----
From: ADSM: Dist Stor Manager [mailto:ADSM-L AT VM.MARIST DOT EDU] On Behalf Of 
Henrik Ahlgren
Sent: 22 November 2010 11:25
To: ADSM-L AT VM.MARIST DOT EDU
Subject: Re: [ADSM-L] DB2: SSD vs more RAM

Or maybe he has a huge amount of DB entries?  If his options are either six SAS 
15K or eight SSDs (50GB each), it means his DB is propably in the multi-hundred 
gigabyte range. If he just needs the IOPS for smaller DB, then he would not 
need 8 SSDs to beat 6 platters, even one or two could be enough. (Just one 
Intel X25E does 35K IOPS random 4K read.) I'm not sure how much doubling the 
RAM would help with operations such as expiration, DB backup etc. compared to 
nice SSD setup.

I'm wondering why so little discussion here on using solid state devices for 
TSM databases? Some of you must be doing it, right?

On Nov 17, 2010, at 7:50 PM, Remco Post wrote:

> SSD to me seems overkill if you already have 24 GB of RAM, unless you need 
> superfast performance and are going to run a very busy TSM server with a huge 
> amount of concurrent sessions.
> 
> --
> 
> Gr., Remco
> 
> On 17 nov. 2010, at 12:16, "Pretorius, Louw <louw AT sun.ac DOT za>" <louw AT 
> SUN.AC DOT ZA> wrote:
> 
>> Hi all,
>> 
>> I am currently in the process of setting up specifications for our new 
>> TSM6.2 server.  
>> 
>> I started by adding 8 x SSD 50GB disks to hold OS and DB, but because of the 
>> high costs was wondering if it's possible to rather buy more RAM and 
>> increase the DB2 cache to speed up the database.
>> 
>> Currently I have RAM set at 24GB but its way cheaper doubling the RAM 
>> than to buy 8 x SSD's Currently I have 8 x SSD vs 6 x SAS 15K


--
Henrik Ahlgren
Seestieto
+358-50-3866200