I think the first thing you need to assess tho is - is it the diskio that is
the bottleneck - if you have a *nix system with plenty of ram, you get a
decent disk cache in ram. Analyse your wait on io stats for your processors,
if this is higher than your actual cpu utilisation then you do have a disk
bottleneck, Otherwise you may be better off getting better/more processors.




-----Original Message-----
From: u2-users-boun...@listserver.u2ug.org
[mailto:u2-users-boun...@listserver.u2ug.org] On Behalf Of John Thompson
Sent: 19 December 2011 13:45
To: U2 Users List
Subject: Re: [U2] Solid State Drives (SSD) and Universe

I am currently attempting to as we speak, but, I don't have any hard numbers
for you.
I have some numbers from a benchmark tool, but, there are so many factors
involved, I can't really tell you whether U2 performance is 30 times
faster... Although I'm hoping this week I can get Universe installed and run
through some jobs to see.

The tool on RHEL 6 is telling me that on using the "sync" io engine, that
random reads are 30 times faster, and, random writes are 60 times faster,
which I find funny.  BUT, I'm no expert on which io engine Universe uses
(sync, libaio, posixaio, etc. etc.)

In my case, I don't work for that big of a company, but, IBM was offering a
40% rebate on some of their solid stuff in October, and our AIX support was
slated to end in April.  That being said though, if you are the guy that has
to research the hardware, I'll give you these pointers that I have learned
painfully...

If you are running on an x86 machine (intel-ish), keep in mind these points:

1) There are a couple of different types of solid state drives.
-SATA, SAS attached to an actual disk controller (These are limited by the
throughput on the disk controller, which they will quickly eclipse) -PCIe
(PCI Express) that plug directly into the PCIe bus of the system (These are
not limited by a disk controller and communicate almost directly with the
CPU/RAM/bus)

The PCIe are not bootable however, but, they bypass the latency of a
traditional disk controller, and are even faster.
They do come with the added complication of proprietary drivers, so if you
don't get good support for this, things can get painful.

2) Be sure and buy enterpise SSD's.  For example, an Intel 320 SSD is
probably not an enterprise SSD.  The quality of the firmware/drivers and
flash memory is pretty key on these things, and the prices range from $200
all the way up to $4,000+ a piece.
Basically, just do your homework on what the predicted life of the drive is.
Don't always pay attention to warranty or hours.  Its more about, "How much
data in GB can I write to this thing before it wears out."
Also the cheap ones really fall short on random write performance which I
think is important in a U2 database.

3) Make sure its in your budget.  They are still at least double or triple
the price of spindle disks (for the enterprise grade stuff).  However, the
performance is more than double/triple, so, the cost justifies itself.

I think IBM has some SSD's offerings for their new POWER 7 AIX machines as
well.

Now for some more specific Vendor advice, as a result of some of my pain I
have experienced the last month or so.

If you go with one of the big boys for a RHEL (Linux) or Windows server,
here is some useful info.

IBM and HP (not sure about Dell) offers mainly two types of SSD's The
traditional SATA ones http://www.redbooks.ibm.com/abstracts/tips0792.html

The PCIe Ones
http://www.redbooks.ibm.com/technotes/tips0729.pdf

*Be careful about how you hook up the traditional SATA ones.* My so called
"Vendor" was supposed to do all of this "checking" for me, but, they dropped
the ball big time.

IBM has a list of controllers that are compatible with certain machines.
http://www-03.ibm.com/systems/info/x86servers/serverproven/compat/us/xseries
/controllers/matrix.html
So make sure that matches up.  I'm sure HP, has a similar posting somewhere.

THEN, make sure the controller can support SSD's.
SSD's behave way differently than regular disks, so, IF you want to use a
hardware RAID controller or something of the like, you must make sure it is
intelligent enough to handle the SSD's.

OR you can just hook it up to an HBA (Host bus adapter) with no actual
intelligence, and then let the OS handle how it deals with the SSD's (i.e.
software RAID, lvm, etc.)  If you know Linux lvm, RAID, or Windows disk
management, this might be the best approach for you.

*Be wary of the vendor you buy the PCIe SSD's from* Like I said, IBM offered
40% off of these guys a month or two ago, but, their support people don't
know a #$%^$## thing about them.

The company that makes these things for HP, IBM, and I think Dell is called
Fusion IO:
They just went public on the stock market not too long ago.
http://www.fusionio.com/platforms/iodrive/

HOWEVER, they have a non compete agreement with IBM, that states that any
IBM branded card, they cannot support, EVEN though, they are the exact same
stinking thing.

So... if its in your budget to get these cards.  Just buy it direct from
Fusion IO, or buy a card that is Fusion "branded"  Believe me, you will save
yourself a LOT of headache.

Other than the newness of it all, there is great potential from what I see.

One of these little fusion io cards, can outperform an entire SAN of spindle
disks for a fraction of the price.
The traditional SATA SSD's aren't too shabby either.

But, its all if the money is there and if you are willing to go through a
learning curve (especially if you are the guy having to deal with the
Operating System setup).
Once the OS is setup, U2 should talk to it just like anything else, I
hope...


On Mon, Dec 19, 2011 at 2:48 AM, Mitchell, Stewart <
stewart.mitch...@symbion.com.au> wrote:

> Hi All,
>
> I am interested in the groups opinion on using SSDs with Universe. My 
> reading leads me to believe there are significant performance improves 
> for I/O and more specifically random reads in the magnitude of 3,000% 
> (30
> times) faster.
>
> Does anyone current use SSDs?
>
> Regards,
>
> Stewart Mitchell
> Business Systems Manager
> Symbion IT
> Symbion Pty Ltd
>
> ________________________________
> Effective October 2011 Symbion Pharmacy Services has changed it's name 
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>
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