Replication slow over WAN connection

[ady_td]

I have a leased line connection between two sites, if i copy normal windows files across the link on an evening I can copy on average 700mb in an hour, when I run a repl;ication job it only get about 300- 350 Mb in an hour. I can not see why it would take twice as long to copy the data.

I have worked the data size that has changed by calculating the size of the VRB file at the replication... 3156Mb / 10 hrs.

Is there anything I can do the speed up this replication job ?

[Vitaliy S.]

Hello Ady,

There are several important differences between just copy operation and VM replication, however could you tell us what job mode are you currently using? Additionally, it would be great if you could give me some background on your infrastructure/setup, so I could see which part might be improved.

Along with that, please search the forums for "WAN connection" topics, as there are existing discussions on how to improve WAN job performance rates.

Thanks!

[Gostev]

Replication has additional overhead of using VMware API versus simply writing to an open file, so the difference is expected.

You may want to try this to get faster transfer speed:
NETEX AND VEEAM SOFTWARE PARTNER TO PROVIDE FREE WAN OPTIMIZATION SOFTWARE FOR NEW VEEAM BACKUP & REPLICATION CUSTOMERS

Our own experience with this solution (although for backup, which deals with already heavily compressed and deduped data):
http://www.veeam.com/success_story_backup_netex_ss.pdf

[Bunce]

Gotta love it it how media releases include things like "the leader in WAN optimization software"....

[Gostev]

What better WAN optimization software you are thinking about? I know a few very good hardware-based WAN optimization solutions, but I do not anything else in mind for software-based.

[Bunce]

To be honest I didn't even get that far -> I stopped reading after the first line..

When I read "WAN Optimisation Software", I think (perhaps inaccurately) of the 'smarts' which do the compressions /deduplication/ etc. - irrespective of whether the software is installed in a dedicated hardware device or in a client OS..

Many hardware vendors also provide software clients that are installed, for example, on laptops for travelling users - therefore crossing the medium between software and hardware vendors.

[ady_td]

Sorry for the late replay, I can not seem to view my post all I get is am erro when I select view your post...

"Sorry but you cannot use search at this time. Please try again in a few minutes."

I have a leased line with BT, 2MB up and 2MB down, when I run the Job it is ove rthe evening or weekend so the link is not getting used much, if I run a quick file copy job of 50MB it takes 5 min, which in avarage gives me 600 mb per hour , but the replication job is half that at 320mb per hour.

what do you mean by "what job mode are you currently using" ?

[Vitaliy S.]

I'm sorry to hear that forum's search doesn't work properly, let me see what we can do with this. Regarding to the job mode...are you using vStorage API - Virtual Appliance mode/Network?

[ady_td]

I am using VMware Vstorage API - network.
enabled VMware tools quiescence
Enable automatic replication integrity check
enable inline deduplication
conmpression optical
use change block tranking
Number of role Role backs 5
enable veeam vss intergration

[Vitaliy S.]

Since network mode is the slowest mode compared to all other, I believe you're seeing expected transfer results. But could you please tell me if you've tried using WAN acceleration tools that Anton posted above?

[ady_td]

where can I get this software from ?
If i replicate to a server on the LAN then the speeds are great so I do not understand why the netowrk API option is reducing the backup speeds ? If I complete file copy with Veeam of 50 MB it take 5 minutes so a good 600 mb a minute so the connection wil take 600 mb per hour.

[Gostev]

Well, again - replication has additional overhead of having to use VMware API commands for each processed block versus simply writing blocks to an open file, so the difference is expected.

WAN accelerators really help to improve the performance, and use the avaialble bandwidth more effectively. You can get trial version of the software directly from vendor (Hyper-IP). As for the free license key, you will only be able to receive it after you buy Veeam Backup.

As for job processing mode, it does not actually matter much for slow links... WAN replication performance is typically always limited by the WAN link speed. You would only see differences in performance between various job processing mode for on-site replication over LAN.

[tsightler]

where can I get this software from ?
If i replicate to a server on the LAN then the speeds are great so I do not understand why the netowrk API option is reducing the backup speeds ? If I complete file copy with Veeam of 50 MB it take 5 minutes so a good 600 mb a minute so the connection wil take 600 mb per hour.

Replication is quite a bit different than copying a file, although I'll admit I would expect the initial replication to be roughly the same. After that though, there can be significantly more overhead than a simple file copy. Why? Because for replication, when a block is changed, you have to read that block from the target, move it to the rollback file, and then finally copy the new block. If you're using ESXi, then all this happens over the WAN, thus basically doubling the amount of traffic that has to cross the WAN.

If you're using full ESX as a replication target, or a Linux server as a backup target this is not as much of an issue because Veeam pushes a small agent to the service console (replication) or the Linux server (backup target) and the local agent handles the movement of data around.

I have quite a bit of experience replicating with Veeam over a 2Mb link. We have an EU site that replicates their servers to our US datacenter and they are connected only with a 2Mb MPLS link. We typically see close to 1GB/hr with initial replication, and significantly better once we implemented WAN acceleration, especially with the incremental passes. We actually just added 3 additional servers for a total of 220GB of data replicated via the 2Mb link. For this initial replication we're averaging about 2GB/hr even with WAN acceleration, but that's largely because a huge percentage of the data being replicated is already highly compressed so we're not getting much benefit from compression, on the DRE/caching features of the WAN accelerator are really coming into play.

[ady_td]

not sure if i have miss read the replys but I am replicating from one ESX host to another ESX host (I did not think Veeam backup supported ESXi) overa 2mb MPLS with out any acceleration and I am not getting 1GB/Hr only 300mb/hr.

I have allready got veeam essentials but it did not come with any WAN acceleration software key, does it not come with all the backup product versions ?

[Gostev]

It does, but is it possible that you bought Veeam before promotion started? If yes, it would be best to contact your Veeam sales representative, to see what can be done.

[st0623]

The HyperIP team at NetEx would be willing to allow you to use a free key for 10 days to accelerate your WAN connection for replication testing. Please browse to www.netex.com/eval and fill out the eval questions, press the "Iagree" radio button and you can download the software for free. Contact me at steve.thompson@netex.com if you have any questions.