Solved

disk io size 4k-512k

Posted on 2013-01-22
4
417 Views
Last Modified: 2013-02-08
i wanted to determine which disk io block size to go with and I am note sure which option is best?  choice range from 4k to 512k? what are the pros and cons?  i have a 2012 server.
0
Comment
Question by:Kylo Ren
  • 2
4 Comments
 
LVL 14

Accepted Solution

by:
BlueCompute earned 400 total points
Comment Utility
In general, larger clusters improve performance at the cost of wasted space. The best size depends on the average size of the files you will be storing on the volume - I've found 16 or 32KB to be a reasonable choice on a window server, but it depends on usage - unless you're trying to make a particularly high-performance environment I wouldn't worry about it too much. The default figures can be found here:
http://support.microsoft.com/kb/140365?wa=wsignin1.0
and some information about he performance impacts here:
http://technet.microsoft.com/en-us/library/cc767961.aspx
0
 
LVL 4

Author Comment

by:Kylo Ren
Comment Utility
ok space may not be that important to me. how much is actually wasted? i just need a rough idea to see what trade off would be.

lets say i have a 500gb volume and i want the best performance (largest cluster size).  how much space can i expect to lose? also are there any other downsides to having a large cluster besides wasted space?

thanks a lot
0
 
LVL 16

Assisted Solution

by:Gerald Connolly
Gerald Connolly earned 100 total points
Comment Utility
well if you have lots and lots of small files, you will waste a lot of space, all it needs is one byte used to waste all the remaining space in a cluster
0
 
LVL 14

Expert Comment

by:BlueCompute
Comment Utility
Basically, the cluster size is the smallest amount of data the file system will allocate. If your file is smaller than this, any extra space is wasted. For a demonstration, create a new text file on your local hard drive, enter 1 character of data and look at the file properties. You'll see the following:

Size: 1 bytes (1 bytes)
Size on Disk: 4.00 KB (4,096 bytes)

This is with a 4k cluster size. The average file size in my current Win7 windows directory is 165KB, but that's a mean average. With a 4k cluster size, I get

Size: 16,771,835,355 bytes
Size on disk: 16,965,893,594 bytes

Which is very little wastage, as most files are >4k in size anyway. To be honest, it really isn't likely to make too much difference to performance or disk usage unless you start going to very large clusters, which doesn't make sense unless you're only dealing with large/fixed size files.
0

Featured Post

How your wiki can always stay up-to-date

Quip doubles as a “living” wiki and a project management tool that evolves with your organization. As you finish projects in Quip, the work remains, easily accessible to all team members, new and old.
- Increase transparency
- Onboard new hires faster
- Access from mobile/offline

Join & Write a Comment

This article is an update and follow-up of my previous article:   Storage 101: common concepts in the IT enterprise storage This time, I expand on more frequently used storage concepts.
This is an issue that we can get adding / removing permissions in the vCSA 6.0. We can also have issues searching for users / groups in the AD (using your identify sources). This is how one of the ways to handle this issues and fix it.
This Micro Tutorial will teach you how to reformat your flash drive. Sometimes your flash drive may have issues carrying files so this will completely restore it to manufacturing settings. Make sure to backup all files before reformatting. This w…
How to install and configure Citrix XenApp 6.5 - Part 1. In this video tutorial we have explained step by step installation of Citrix XenApp 6.5 Server on Windows Server 2008 R2 is explained in this video. We have explained the difference between…

772 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question

Need Help in Real-Time?

Connect with top rated Experts

14 Experts available now in Live!

Get 1:1 Help Now