Unsolved
This post is more than 5 years old
9 Posts
0
11171
May 20th, 2009 04:00
Performance - MD3000i
I have about 8 Virtual Disks in one Disk Group. Would it be adventagous to spread across several Disk Groups?
Using a RAID 5 configuration, logic tells me that I would acheive better performance by creating more Virtual Disks in one Virtual Disk Group.
Does anyone suggest otherwise? If so, please explain.
No Events found!
mrokkam
154 Posts
0
May 20th, 2009 09:00
I agree with Dev Mgr. Having Virtual Disks over separate disk groups will ensure that they do not interfere with each other, from a performance standpoint.
You might be able find other ways to tune your array for best performance for your application from this white-paper
http://www.dell.com/downloads/global/products/pvaul/en/pvault_md3000_whitepaper.pdf
-Mohan
Dev Mgr
6 Operator
•
9.3K Posts
0
May 20th, 2009 09:00
Actually; logic says if you create more virtual disks in a disk group, you'll get less performance as they all share the same physical drives so when one virtual disk is 'busy' (getting hit hard by the server), the others on the same disk group will suffer in performance. By using 2 or more disk groups, whatever affects one disk group never affects the other diskgroup.
phil_couto
9 Posts
0
May 20th, 2009 09:00
Thank you both for the advice.
I have to find a happy medium between both. My concern is that every time I create a new RAID 5 disk group I eat up another third drive. Doing this for many Disk Groups would eat up my storage.
Thanks
phil_couto
9 Posts
0
May 20th, 2009 10:00
Thanks again - the white paper is awesome!!!
JOHNADCO
2 Intern
•
847 Posts
0
May 20th, 2009 10:00
If you decide to build one big really fast raid 5 group and create all your virtual disks in that group? Make extra sure any sort of heavy VM gets a dedicated VD and LUN. In our testign this ended up being gold for us as far as overall best performance.
mrokkam
154 Posts
0
May 20th, 2009 10:00
It is definitely a balancing game of space efficiency vs performance and determining the best combination for your specific application.
If you have any idea as to which virtual disks will get hit the most or which VDs will have heavy IO at the same time, you could split those into separate disk groups. The white paper above also has a couple of other settings that can be modified to improve performance if you know the type of IO.
-Mohan