Open-E/Vmware question

[TRoffo]

Hello,

I would like to use open-e DSS in the following manner to use as storage for vmware 2.0 servers, but am not entirely sure it is possible:

* 2 Open-E DSS servers:

* 1 main server running as NFS NAS
* 2nd server doing block based replication (sync) from the first NAS

I'm not positive this can be done, or I need to use file based replication for this - if so, does file based replication work well with vmware virtual servers? These would be a lot of 2GB files that are continously changing and are always open - is there a way for me to sync this to the 2nd open-e server?

I'm not looking for active failovers, just a passive machine replicating the first and which can manually be activated in case of trouble.

Thx for the feedback!

[To-L]

I am not sure if it has been tested with VMware 2.0.
You could download 2 copies of the Demo CD and try Volume replication with DSS.

[sap]

I don’t know if this will have an effect on ESX 2 on NFS but i can tell you that Open-E and ESX 3.x do not go together very well using block level access. E.g. ISCSI or Fibre Channel.
If I where you i’d do a lot of testing first.

Anyways… that’s my two cent’s :-)

Regards.

Stig.

[toepytoe]

I have read some post were file I/O workes better with VMware.
May want to change to file I/O and check it out

[beng]

Hello,

I would like to use open-e DSS in the following manner to use as storage for vmware 2.0 servers, but am not entirely sure it is possible:

Well it's possible, but then I would ask, why not use ESXi?
The only reason I can think of is that your Host hardware is not compatible?
We have found the key is to ensure a decent RAID controller(Eg Adaptec 2405 and flash SATA disks to Raid compatible firmware if required.

We run both here, and ESXi beats VMware server for robustness, hands down.
VMware server is nice for running simple little VM's with not a lot of I/O and/or CPU requirements, but it really has limits for manageability.
How were you planning on backing up the host?

RE Replication, not 100% sure how you are planning to do this, I'm assuming you want to replicate the VMware Server VM store while it has running VM's?
We have not tried this in production, simply because iSCSI seemed a better way to go and the NFS performance was not as good as iSCSI.

But if you use ESXi and iSCSI then File I/O and BlockI/O replication.
It works really well, just follow the Open-E Whitepaper to set it up. And as per Todd's advice don't enable Writeback cache on your iSCSI Targets.
The end result is that the data is replicated at the block level, so you only xfer changed data.

Rgds Ben.

[beng]

I don’t know if this will have an effect on ESX 2 on NFS but i can tell you that Open-E and ESX 3.x do not go together very well using block level access. E.g. ISCSI or Fibre Channel.

G'day Stig,
Just to clarify the original poster is using VMware Server 2.0 not ESX 2.x, so these are very different animals.

And for our two cents, in lightly used (eg < 50 users Windows Domain Controllers. etc) block I/O iSCSI has been fine. :-)
But, and forgive me if this is not the case, all of the posts I have seen from you refer to DSS Lite?(circa Jan 2008?) This is not the same core as the current DSS, and since Troffo has posted in the DSS forum I am assuming, again, that he is using the current version (Demo or Paid).
Our experience was that there were major improvements in iSCSI performance with recent versions of DSS. (And for anyone reading this post, align your local VMFS partitions! you won't be sorry if you do large sequential xfers.)

Rgds Ben

[To-M]

Thanks Ben on the ESXi info as you just saved me some time as I was thinking on setting up some servers this coming weekend.