[Gluster-users] Clustered storage solution

[Alex Crow]

On 20/04/15 09:19, Thorvald Hallvardsson wrote:
> Hi guys,
>
> I have a question.
>
> I need to setup a HA storage clustering on Linux. The main objective 
> is to make the cluster HA and as an extra feature load balanced as 
> well. The problem I'm facing with is the whole system is going to run 
> on Hyper-V ;-). That's the tricky bit. All the storage backends and 
> disk presentation will be done by Hyper-V via shared VHDX. Generally 
> this means that Hyper-V ties 2 (or more) hard drives into one and can 
> share it across multiple internal VMs. There is no magic when it comes 
> to Windows side of things as Windows VM supports this solution 
> natively. We have a bit of hard nut to crack if it comes to Linux side 
> of things. So I will be given a shared VHDX for my Linux Storage VM 
> and I need to create a cluster from these shared VHDX'es to make the 
> data HA and resilient. This scenario can be compared to the single SAN 
> storage presenting out the same LUN/disk to multiple VMs at the same 
> time. This is what Windows Hyper-V does in the backend to give me 
> VHSX. Single VHDX needs to be mounted on multiple storage VMs and then 
> these VMs needs to have a cluster aware file system on that VHDX and 
> present it out to the Linux clients which can simultaneously read and 
> write data onto it. I hope this is pretty clear.
>
> I'm just wondering if GlusterFS is going to work in my configuration. 
> If so can you please give me some configuration hints on how I should 
> configure GlusterFS. If GlusterFS is not something I should look for 
> can you please give me any suggestion on what I should go and try with ?
>
> Thank you in advance for your help.
>
> Regards,
> TH
>

Hi,

GlusterFS is not a shared-storage filesystem. It combines existing 
non-shared filesystems into a single network filesystem. Effectively 
what you are doing is re-exporting shared storage from multiple VMs, so 
you'd probably be better of using a filesystem like OCFS2 or GFS on the 
VHDX devices and using two or more VMs running an iSCSI target such as 
LIO or SCST to give you MPIO access to these devices.

Unless what you're saying is to set up a separate VHDX, one or more per 
VM, put a normal filesystem, eg XFS on top of these and combine them 
with GlusterFS (using replicate or distribute for resilience) then that 
would work fine (although with possible performance issues from the 
extra layer between GlusterFS and the real disks.

Cheers

Alex

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