ucs 210 raid 6 question

[vijendra Saravanamuthu]

hi all,

we have a ucs 210 with a LSI 6G MegaRAID 9261-8i card .  also it has 4x146GB 6Gb SAS 15K RPM SFF HDD.  it is configured with raid 6 with all 4 HDD in the virtual HD group.  it appears it only gives me about 278GB.  pretty much half of 4x146.  is that make sense for raid 6?

we have another c220 with 6x300HD with raid 5 gives about 1.4TB.  (way more than half).  raid 5 is pretty much same as raid 6 and gives little less than raid 5 in size.  That's why it doesn't make sense for ucs210 with 4x146 HDD. 

can someone clarify this?

much appreciated.

thanks

vijay

[Manuel Velasco · Accepted solution]

Hi  Vsaravanamuthu,

The values that you are getting are expected, what you have to know is that for raid 5 you have only ONE drive failure for fault tolerance and RAID 6 you have TWO drives for fault tolerance. It would make sense that you see bigger capacity from raid 5 than raid 6.   You can also find online raid calculator that will give you and idea of the expected raid volume capacity (see below).

Raid Calculator

http://wintelguy.com/raidcalc.pl

Let me know if this helps and don't forget to rate any useful answers.

[vijendra Saravanamuthu]

Hi,

I think you have the correct answer.  i punched in teh numbers into the raid calculator and it gives me the exact storage size 278GB.  wow..nice thanks.

that leads me to another question since we will be installing 3 VMs on it with size (80, 200, 146 = 426 required).  i can install another 2 x146GB makes the raid give me 556GB.   so this new space will not only hold those 3 VMs but also ESXI will be installed on this as well.  do you think adding 2 HDD make sense and give me the space i want with those things intalled?

thanks a lot

vijay

[Manuel Velasco]

Hi Vijay,

Yes, adding two drives will be fine since the OS only uses a few Gigs.

See below.

http://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1026500

Let me know if this helps and don't forget to rate any useful answers.

[vijendra Saravanamuthu]

thanks a lot.  it did answer my questions.