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New to VSA

Occasional Contributor

New to VSA

I'm looking at scale out storage solutions for our vmware estate and am interested in what The 10TB VSA can offer us. FYI we have 150 VMs, and 6TB of datastore required. I'm provisioinally proposing a 5 node ESX cluster, all DL380 Gen9, 256GB, 2xCPU, with something like 3x300GB in RAID 5 SSD tier 0, and 8x600GB 10k SAS in RAID 5 tier 1, with AO enabled. I have several questions and would appreciate any thoughts....

1. Is anyone running a similar sized enterprise and setup, and how well has this performed for you?
2. I'm interested to know what happens if a VM on host A is DRS'd or vMotioned to Host B. I'd be worried that data marked "hot" on host A was not marked hot in host B and that the VM would therefore experience degraded performance. Thoughts?
3. How do any of you think the performance of this setup might stand up against say a 3 node StoreVirtual 4335 cluster?
4. Is there any way to configure VSA to create some LUNs higher SSD ratios than others? (I'd like the facility to place some VMs on higher tiers, and guarantee it, rather than hoping AO will tier the data some VMs will need)
5. Do writes get complete when they're written to tier 0 on host A, or does the write not complete until host B has written it to tier 0 as parity?
6. Any overall thoughts from your own production instances of VSA/ESX and how its performed?
7. When you later extend a cluster by adding another host & VSA does the cluster redistribute data again across the entire cluster and how troublesome is this overhead?
8. All this is for us replacing an old HP EVA 4400, and we want to have a scale out software defined solution that provides easier scalability, but with good performance too. Do you think the VSA is fit for purpose for such scenarios, or have any of you been bitten and would recommend alternatives (vSAN, Nutanix, StoreVirtual 4335, etc.)

Thanks people

Re: New to VSA

Let me try to answer at least some of the technical questions:


1. I can't share any customer information.


2. The compute VM would still be accessing the data of the same volume provisioned from the StoreVirtual VSA cluster. Hence the data location and the sub-lun tiering will not change if you move a VM from one ESX host to another ESX host. If you do migrate to another datastore, i.e. another StoreVirtual VSA volume, then the sub-lun tiering of the VSA is adjusting within a matter of minutes.


3. I would expect to reach with the 5-node VSA cluster at least a similar performance level as with a 3-node 4335 cluster. Performance in general is hard to predict, because it will depend at the end a lot on the demand the applications you are running can generate.


4. A StoreVirtual cluster with two tiers allows you to either pin volumes on the slow tier (tier 1) or to enable the sub-lun tiering for a volume (which is the default). If you want to have volumes dedicated on SSDs, this can be achieved by creating a separate cluster using only SSDs. If you do combine multiple cluster in a single management group, then you are able to move volumes back and forth between clusters with a mouse click without any downtime to the connected hosts.


5. Writes to a Network RAID 10 volume are acknowledged when both data copies  are written to the battery-backed cache of the RAID controller.


6. As an HP employee, I can't comment on customer installations, but I did see in my lab environment, that StoreVirtual configurations are showing a linear scalability for performance and capacity - I tested this up to a 10-node cluster.

Generally StoreVirtual VSA is designed for multiple, random IO, transactional type workloads.


7.  When another VSA is added the cluster will automatically restripe the data to use all nodes and all disks in a cluster.  The speed of this restriping is defined by the bandwidth allowed for internode communication. This bandwidth can be adjust if needed; the default setting prevents restripes from hurting end-user workloads.


8.  StoreVirtual is very good at providing a very simple yet highly available storage environment.  Understanding the performance requirements is where I would start.  An EVAPerf command can be run if you have a CommandView station set up.   This can be provided to your HP storage rep and they can extract the info to show IOPS.   It is very difficult to know if the sub-LUN tiering (Adaptive Optimization) will help a given environment so I recommend using 10K spinning disks to cover the average IOPS and leverage SSDs for burst times.  

Neighborhood Admin

Re: New to VSA

Tom's answer is spot on.  A couple things I'll add:

Let me know if you have questions or if you want to talk to a local resource.

Honored Contributor

Re: New to VSA



Most of the answers are already answered, want to add some additional information...


The only way to be sure that you have some volumes using the SSD's is to unselect AO on the other volumes. By unchecking AO on some volumes you will have them stored on the SAS drives only... Volumes with AO will be placed by default on SSD, 'not-so-hot' data will be moved to SAS. But initially it will be stored on SSD...


I have a lot of customers today with a similar setup, some with 2 servers with VSA, others with up to 8 servers with VSA. Both with SAS only and SSD/SAS setup... And I see similar performance compared to the 4335 if you take into account the same number of spindles, right sized VSA and good networking (10Gb and low latency).


Besides that I have customers with EVA going for StoreVirtual when high-availability is more important, others go to 3PAR when performance is the key request... Not that VSA is slow (when you do good sizing, 3PAR has the advantage with its build-in ASIC...


On my blog you will find quite some information on StoreVirtual andother HP storage related stuff... For instance you will find installation instructions for the quite new MEM multipathing extension module which will give you more intelligent multipathing and so better performance on VMware...


If my post was useful, clik on my KUDOS! "White Star" !
Occasional Contributor

Re: New to VSA

Thank you for taking the time to reply with such good info. If I were to go with a higher number of smaller HDDs to increase spindle count, would that be a "good design practise"? - I'm thinking the 24FF DL380 gen 9, full, running RAID 50.

Which factors tend to affect performance the most?
SSD ratio?
Spindle count?
Controller cache size? (I'm going with 4gb)

Considering my spec above, and the various costs of each of the above ways to improve performance, where is the best place to spend your $$$'s ..... ?

Honored Contributor

Re: New to VSA

like almost everything in the storage world...  it depends.


upgrade controller+cache if you have short-term bursty IO.

upgrade more SSDs if you have longer duration high IO

more spindles if you need more raw storage and/or a little more IO.


For the VSA's... assuming you have a decent SSD size layer you are happy with, more tier1 HDDs can almost be better as it will speed up the slower tier some and provide more storage space...  keep in mind that with the VSA modle, you really only get 1/2 the actual usable space of any drive you attach to the system after you take NR10 into account.