HPE StoreVirtual Storage / LeftHand
cancel
Showing results for 
Search instead for 
Did you mean: 

P4300 SAN Starter DR Question

vipes27
Occasional Advisor

P4300 SAN Starter DR Question

We're looking at getting a P4300 G2 SAN Starter and I'm wondering about the difference between using them for DR. I understand if you want them redundant they have to be in the same location. If we have an identical server at another location, can we split up the SAN and have one at each location? What's the drawback?
8 REPLIES
Bart_Heungens
Honored Contributor

Re: P4300 SAN Starter DR Question

Hi,
Yes you can pull those 2 boxes apart. Network RAID will make that all data blocks will be spread accross the 2 sites.
However there are some drawbacks.
HP suggests to have at least 2 boxes per site which means that you would need 2 starter kits...
You also have to think about split-brain situations on network level where the implelemtation of the so called FailOver Manager FOM is required.
I have done 10's of installations like this and have great experiences with it but you need to know what you are doing...
--------------------------------------------------------------------------------
If my post was useful, clik on my KUDOS! "White Star" !
My blog: http://blog.bitcon.be
vipes27
Occasional Advisor

Re: P4300 SAN Starter DR Question

Thanks for that explanation. I know talking with our HP reseller, they suggest a starter at each location as well. I guess my thought is to replicate the two SANs nightly and run off of the backup SAN if there's ever a problem with the primary one. What is the process for running off of the backup SAN in that case? Could we just move our VMs to the backup server that would be attached to that SAN and run off that?

Thanks again.
Bart_Heungens
Honored Contributor

Re: P4300 SAN Starter DR Question

What is the line speed and latency between the 2 sites.
The best would be that it is fast enough to do synchronous replication. Then you can move VM's with a regular vMotion...
If the bandwidth is not sufficient, you will have to use Remote Snapshot technology...
I do not have practical experience yet with snapshotting VMFS volumes, but I read in other forum topics that it should be working...
--------------------------------------------------------------------------------
If my post was useful, clik on my KUDOS! "White Star" !
My blog: http://blog.bitcon.be
vipes27
Occasional Advisor

Re: P4300 SAN Starter DR Question

I'm not sure what the latency is, but we have a Cisco wireless bridge between the two sites at 54 Mbps, which obviously isn't enough. We've talked about replacing that bridge with a new one, but I don't know if they make ones with 1GB speed.

Could we move the VMs with Vmotion and run off of the off-site server and SAN?
Bart_Heungens
Honored Contributor

Re: P4300 SAN Starter DR Question

54Mbps is definitely not enough. General rule is 50 MBps per box so you will need 1Gbps at least with a max latency of 2 ms...
Otherwise you will need to use remote snapshots so make a snapshot on 1 side and replicate it to the other site towards a remote volume.
At the other site you can make a remote volume back a primary volume and do the test with an ESX server over there to mount the volume and import a VM on it... Should work... But like I said personaly not tested yet...
--------------------------------------------------------------------------------
If my post was useful, clik on my KUDOS! "White Star" !
My blog: http://blog.bitcon.be
vipes27
Occasional Advisor

Re: P4300 SAN Starter DR Question

So within VMWare, we'd take snapshots of the servers and replicate them offsite. Then, on the backup host, mount the snapshot to the backup SAN?

Would it be possible to just point the main host to the backup SAN or is the speed not enough?

Thanks again.
Bart_Heungens
Honored Contributor

Re: P4300 SAN Starter DR Question

Until now (SanIQ 9.0) there is no integration so far (it is promised in a future upgrade) for VMware snapshots.
The snapshot I mean is on VMFS SAN volume level and replicate that to the other side.
P4000 (Lefthand) sees volumes, not the data (the VM's) on it...
--------------------------------------------------------------------------------
If my post was useful, clik on my KUDOS! "White Star" !
My blog: http://blog.bitcon.be
chal_1
Occasional Advisor

Re: P4300 SAN Starter DR Question

Attached doc maybe useful;

HP StorageWorks P4000 SRA for VMware SRM

There is also another doc at;

http://h20195.www2.hp.com/v2/GetPDF.aspx/4AA3-0261ENW.pdf