× The internal search function is temporarily non-functional. The current search engine is no longer viable and we are researching alternatives.
As a stop gap measure, we are using Google's custom search engine service.
If you know of an easy to use, open source, search engine ... please contact support@midrange.com.



Gad

+1

Back in 2012, when I went from 20- 141 15kHDD to 18- 177GB SFF-2 SSD w/ eMLC (IBM i) Enterprise, my run times saw a 4x improvement, 1 hour jobs ran in 15 minutes.
As Larry stated, the DASD controllers are also equally important.
I went from 2780 Ctlr w/Aux Write Cache maximum compressed write cache of 757 MB and a maximum compressed read cache size of 1 GB to dual 5913 PCIe2 1.8GB Cache RAID SAS Adapter Tri-port 6Gb.

I will be doing this again, but not from HDD.
I'm still waiting confirmation on the amount of cache on the P9 imbedded SAS controller.
As an option, I looking at dual PCIe3 12 GB Cache Raid Plus SAS Adapter Quad-port 6 gb x8 EJ14.

Paul

-----Original Message-----
From: MIDRANGE-L [mailto:midrange-l-bounces@xxxxxxxxxxxx] On Behalf Of DrFranken
Sent: Saturday, March 31, 2018 2:12 PM
To: Midrange Systems Technical Discussion
Subject: Re: Is this S914 config a good replacement for my S814

I can say with confidence that replacing a total of 25 15K Spinny drives with 18 SSDs will make you a very happy admin! I would split into 2 RAID sets to enable each of the controllers to 'own' one set.

That thing will be more like a Hellcat next to a slant-six Duster!


- Larry "DrFranken" Bolhuis

www.Frankeni.com
www.iDevCloud.com - Personal Development IBM i timeshare service.
www.iInTheCloud.com - Commercial IBM i Cloud Hosting.

On 3/31/2018 2:02 PM, Gad Miron wrote:

Jim, Dr.


Thanks for the educative responses

I'll have my BP look into the MPG option.

I'm quite happy to learn that SSD write speed are on par with it's
read speed.

Current 814 machine has 18 59E0 (283Gb 15K) disks in CEC plus 8 19B1
(283Gb 15K) residing in expansion EXP24S5 (in two Raid5 sets) All
disks driven by a dual controller in the CEC (forgot it's type but it
has a 4 Mb cache I think) Memory is 128GB.
(this is no Prius me think)

819 candidate is to have 512 Gb memory and 18 931GB Mainstream SAS 4k
SFF-3 SSD - all in SEC. with dual controller (again I couldn't find
the type but this one has 7 Gb cache)

So

Do 18 SSD "spindles" suffice ?
What raid configuration is best, two sets of 9 SSDs? one set of 18?
what about hot spare?

looking at the link you referred me to I'v noticed the following statement:

With their large capacity and lower cost per gigabyte, the drives can
provide a very cost-effective and footprint-effective solution for
many mainstream (*previously known as read-intensive*) configurations.
Note these drives are designed for *workloads with modest write
requirements....*

What say you?

TIA
Gad








message: 4
date: Sat, 31 Mar 2018 11:45:02 -0400
from: DrFranken <midrange@xxxxxxxxxxxx>
subject: Is this S914 config a good replacement for my S814 Re: (was:
What is the difference between Flash storage and a Flash Storage
system like the V9000/V7000)

Gad,

Good idea to change the Subject if you want to catch the eye
of those who can help!

Jim already made several good points but overall I would
amplify his suggestion that we don't know enough. You might have only
7 drives that provide that 6TB of space. If you do they are 1.1TB and
10K RPM so the proposed SSD configuration would look like a Top Fuel
dragster against my Prius. Or you might have multiple drawers of
139GB 15K RPM drives on several large cache controllers in a mirrored
environment. MASSIVE difference between those two options!

In either case it's likely the new SSDs will win big but
we're guessing.

One more thing, Where are you getting the 'SSD writes are
only slightly faster than HDD writes' statement? Waaaaay back the
original 70GB SSDs that IBM sold for a kings ransom had write speeds
of about 120MB/s which is rather comparable to a 15K spinning drive
on streaming writes. But the SSD generations released in 2016 were
well over 400MB/s (as high as
470MB/s)

And in IBM's latest SSD announcement they state: Write
performance is "more than 25 times that of a standard 15K HDD" and
"the number of drives is still a factor in achieving satisfactory
performance, especially for IBM i."

Read all about em here:
https://www-01.ibm.com/common/ssi/cgi-bin/ssialias?infotype=
an&subtype=ca&appname=gpateam&supplier=897&letternum=ENUS117-086

So I think you have some outdated information there. Even PC
SSDs today are pretty close to parity for read and write performance
with writes only a tick slower than reads any more.

- Larry "DrFranken" Bolhuis

www.Frankeni.com
www.iDevCloud.com - Personal Development IBM i timeshare service.
www.iInTheCloud.com - Commercial IBM i Cloud Hosting.

On 3/31/2018 6:45 AM, Gad Miron wrote:
Calling all sages

We're going to replace our S814 (3 cores activated) 6 TB internal
HDDs machine with a S914 (3 cores activated) 18 931GB Mainstream SAS
4k SFF-3 SSD machine.

Is this a viable DASD configuration for a write intensive environment?
(it is common knowledge that SSD writes are only slightly faster
then HDD writes right?)

TIA
Gad



--
This is the Midrange Systems Technical Discussion (MIDRANGE-L) mailing list To post a message email: MIDRANGE-L@xxxxxxxxxxxx To subscribe, unsubscribe, or change list options,
visit: https://lists.midrange.com/mailman/listinfo/midrange-l
or email: MIDRANGE-L-request@xxxxxxxxxxxx Before posting, please take a moment to review the archives at https://archive.midrange.com/midrange-l.

Please contact support@xxxxxxxxxxxx for any subscription related questions.

Help support midrange.com by shopping at amazon.com with our affiliate link: http://amzn.to/2dEadiD

As an Amazon Associate we earn from qualifying purchases.

This thread ...

Follow-Ups:
Replies:

Follow On AppleNews
Return to Archive home page | Return to MIDRANGE.COM home page

This mailing list archive is Copyright 1997-2024 by midrange.com and David Gibbs as a compilation work. Use of the archive is restricted to research of a business or technical nature. Any other uses are prohibited. Full details are available on our policy page. If you have questions about this, please contact [javascript protected email address].

Operating expenses for this site are earned using the Amazon Associate program and Google Adsense.