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Dell HPC NFS Storage Solution - High Availability (NSS-HA) Configuration with Dell PowerVault
MD3260/MD3060e Storage Arrays
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3. Dell PowerVault MD3260 and MD3060e storage arrays
As compared to previous versions of the NSS-HA solution, a major change in the current version is the
introduction of the Dell PowerVault MD3260 and MD3060e storage arrays. These arrays replace the
PowerVault MD3200 and MD1200 storage arrays used in previous NSS-HA solutions.
With the introduction of the 4U, 60-drive PowerVault MD3260 and MD3060e dense-enclosure storage
arrays, storage capacity can be increased significantly while reducing the NFS storage solution’s
footprint. The PowerVault MD3260 offers similar software, firmware, and management features as the
PowerVault MD3200 series 2U arrays. However, for the same storage capacity, the PowerVault MD3260
and MD3060e storage arrays reduce the rack space footprint by 2.5 times (60 vs. 24).
The PowerVault MD3260 is an RBOD with two RAID controller modules in the storage array. The
PowerVault MD3060e is also a 4U, 60 drive dense enclosure expansion box, but it is used as a JBOD
(similar to the PowerVault MD1200) to extend the capacity of the PowerVault MD3260.
Figure 2 shows the front of a PowerVault MD3260/MD3060e dense-enclosure storage array. It has five
drawers, and each drawer holds twelve 3.5 HDDs, for a total of 60 drives. With 3TB NL-SAS drives, each
high-density storage array can provide up to 180 TB of raw capacity.
PowerVault MD3260/MD3060e dense-enclosure storage array Figure 2.
Due to the different physical characteristics of the PowerVault MD3260/MD3060e, some configuration
parameters must be changed from previous NSS-HA versions to tailor the design to these new storage
arrays. These parameters include the number of disks in a RAID virtual disk and the logical volume
layout and stripe size. Details of these new parameter settings and the associated high availability
functionality and I/O performance tests performed in the Dell HPC lab are provided below.
Virtual disk configuration:
o A RAID-6 8+2 layout is adopted for the current version of the NSS-HA solution, while
RAID-6 10+2 is used in the previous versions. The major reason for this change is to
enhance data availability and reliability. In a PowerVault MD3260/MD3060e storage
array, a virtual disk consists of ten disks across all five drawers, two disks per drawer.
Thus, if a single drawer fails for any reason, the virtual disk can still work, because a
RAID-6 virtual disk is able to tolerate two concurrent disk failures. In the previous
versions, a single PowerVault MD3200/1200 storage array provided 12 disks. A RAID-6
10+2 design was the best way to utilize all of the disks in that configuration.
Logical volume configuration: