Dell Server RAID and Virtual Disks

I bought a refurbished dell r720 with 16 - 600Gb sas drives.  It came configured with one single RAID 5 volume.  What are some suggestions for volume and RAID level.  I plan on using as a Windows 2012r2 host for Hyper-V.
TrailShredderIT ManagerAsked:
Who is Participating?
 
ArneLoviusCommented:
RAID10 will give you the best performance, RAID5 the best capacity, RAID6 gives you better availability than RAID5.

These days I would not suggest using RAID5 if RAID6 is available, the ability to have ANY two disks fail is key.

If it is a general purpose Hyper-V host , and if you wanted the options of increasing capacity later down the road, I would consider having a single RAID6 volume  and partition within Windows for a boot volume and a data volume, alternatively, you might want to boot from a 2 disk RAID1 and have the rest as a RAID6

The last time I looked, while it is possible to expand a PERC vdisk on a PERC array, this is only possible if it is the only vdisk on the array, if you have more than one vdisks, it is not possible to expand any of them.
0
 
TrailShredderIT ManagerAuthor Commented:
So, on your alternate suggestion, do you mean to use 2 of the 16 drives and configure as RAID 1 and the other 14 as RAID 6?
0
 
PowerEdgeTechIT ConsultantCommented:
Yes, as opposed to:

1) all 16 in one Virtual Disk (where you would need to install in UEFI mode)

2) creating two Virtual Disks across all 16 disks (one small enough for the OS, the remaining in a second VD for data, but you cannot expand in this configuration)
0
Ultimate Tool Kit for Technology Solution Provider

Broken down into practical pointers and step-by-step instructions, the IT Service Excellence Tool Kit delivers expert advice for technology solution providers. Get your free copy now.

 
ArneLoviusCommented:
Yes, a RAID1 of two disks, and a RAID6 of 14 disks.

Using a boot volume of >2TB forces UEFI mode, however I would use UEFI in preference to BIOS.
0
 
Philip ElderTechnical Architect - HA/Compute/StorageCommented:
My EE article Some Hyper-V Hardware and Software Best Practices explains how we would set things up.

One RAID 6 array with two logical disks:
75GB for host OS
Balance GB/TB for Hyper-V VM Data

The article explains why.

And, as far as performance goes, 16 disks in a RAID 6 array with a RAID controller that has 1GB or more non-volatile (flash) cache set in Write-Back Mode would perform as good as a RAID 10 array. BTDT.

Our testing and expectation for storage is 250 IOPS per disk with 800MB/Second mean throughput in an eight 2.5" 10K SAS disk RAID 6 array. If the storage stack is set up for online transactional type workloads then we'd be seeing 350-400 IOPS per disk and about 400MB/Second mean throughput. It's all in the stack as far as expected performance.
0
 
Gerald ConnollyCommented:
NB RAID-5 is no longer recommended for use in the Enterprise, especially with disk sizes over 700GB due to the extended disk rebuild times for disks over that size. This rebuild time means that the risk of a second disk failing while the first failure rebuilds, has become unacceptably high! Use RAID-1, RAID-6 or RAID10
0
Question has a verified solution.

Are you are experiencing a similar issue? Get a personalized answer when you ask a related question.

Have a better answer? Share it in a comment.

All Courses

From novice to tech pro — start learning today.