RAID 10 and Thick vs. RAID 6 and LSFS

[Branin]

I need about 6TB of storage and have 10 2TB SAS 72000RPM disks (on each of my 2 servers). What gives better performance, while keeping the risk to an appropriate level?

1) Put the disks in a RAID 10 array, so 10TB total of usable space, and go with thick provisioning, since I don't have the required 2.5x to 3x disk space available for LSFS?
or
2) Put the disks in a RAID 6 array, so 16GB of usable space, with LSFS enabled?

I have about 50GB of RAM or so for a Level 1 cache, and 2 1.2TB SSD drives for a Level 2 cache (planning on putting them in a RAID 1 configuration).

I'm assuming that Level 2 caches will start working again pretty soon, and that even though I don't have the recommended 5-10% of RAM for a Level 1 cache for LSFS (which is about 600GB), that I would still be ok. Is this a good assumption?

(My RAID controller is an LSI 9361-8I, with CacheVault included, and my plan is to do a converged compute+storage 2-node Hyper-V cluster, if this makes a difference).

Thanks!

[Vladislav (Staff)]

Hi,

What if I advise you to use all your spinning disks in RAID0 configuration, since you are going to use StarWind that ensures redundancy?

Pros:

• fast like hell

• 20TB usable space

• more than enough RAM for L1 cache

Cons:

• -

LSFS was designed for low cost HDDs, when workload is mostly shifted to the CPU and RAM, thus I think the option for you is thick-provisioning on top of RAID10 or RAID0.

[Branin]

Thank you very much for your recommendation. However, it appears the downsides to thick provisioning include lack of support for the hardware VSS provider (to increase backup efficiencies) as well as deduplication. Do you still recommend thick provisioning even with those limitations?

Thank you!

Branin

[Vladislav (Staff)]

Windows still has its own VSS provider

Deduplication reduces the size of LSFS device, but actually LSFS image may occupy a lot of additional space, because of snapshots and its architecture.
http://knowledgebase.starwindsoftware.c ... scription/

Please try different implementation and let us know what works for you best.