Cisco Network Accelerated Serverless Backup

Unanswered Question
Jan 30th, 2007


Is anyone actually using Cisco Network Accelerated Serverless Backup (NASB)? I have a project in the making of using HDS arrays and VTL's but in different datacenters.

When you read the sales blurb on NASB, it does look good especially in that remote datacenter backup model.

Is there any doco around that provided technical overviews of how it can be done. Eg, array at one site, NESB gets the data and throughs it across a Fibre Channel or IP network to the VTL.

Where would the SSM be in that model? Would you need one of them at each datacenter?



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inch Tue, 01/30/2007 - 16:37


Depending on which product you use...

You will need a SSM at each site. Some vendors are: topio (now netapp), EMC and falconstor.

There is not much take up of this in .au but you should have a chat to Cisco directly about it :)

stephen2615 Tue, 01/30/2007 - 17:04

Hi Andrew,

What do you mean by product? Is that a backup product?

Most of the Cisco people are over in SF partying right now (opps I meant attending a conference). Lucky devils.

There has to be some doco somewhere on this. There is an option in the HDS USP for serverless backup but even that is just a paragraph on the website with no other doco to read.


inch Tue, 01/30/2007 - 22:00

Basically cisco developed the hardware and a API for the SSM...

Vendors then got oon board and bought the good companies that developed a platform for the SSM.

You need to choose which one you can afford :)

stephen2615 Wed, 01/31/2007 - 01:41

I think that the serverless backup has nothing on the MDS. I think that SANTap and virtualisation does need something on the switch. After digesting that ESG doco on the SSM's, the interesting point is:

During a backup, data travels from the storage system directly to the tape drive. The backup is started and managed using

existing backup and restore software that has been upgraded to use Cisco MDS services to move the data. The data movement within the MDS switch is handled by a Storage Services Module (SSM) that plugs into the MDS switch. The backup software and the MDS switch communicate using an industry standard SCSI command called XCOPY.

So I read that as the only thing needed is a licence for the SSM and the right backup software which I think we might have already.

I also would like to know why I would need two SSM's for a datacenter to datacenter backup. Basically, if we have one MDS in one datacentre where the HDS is, it would then just need to send the data via SAN extension to the other MDS (via a trunking port channel) to the VTL.

If we are using one ONS 15454 in each datacenter, then we probably would only need one MDS director at each end as the ONS is probably a single point of failure as well.

Anyway I digress. Hopefully someone at Cisco can comment on this and ofcourse, Andrew is most welcome to add more.


inch Wed, 01/31/2007 - 02:15


You can get serverless backup via mds/ssm... but the SSM is nothing without the right software to tell the SSM what to do. You of course can get other software packages that do serverless backups.

SANTAP and the associated software package (EMC/Kashya & Netapp/Topio) move data to remote sites over IP not via fibre channel :-) This is true with replication and SANTAP but I'm not 100% on serverless backup.

For example, flows would look like this:

Server/Tape/Array->MDS->SANTAP Application->IP WAN->SANTAP Application->MDS->Server/Tape/Array

If Terry could confirm/deny this it would be great :-)

I have no exp in the optical space so I can?t comment there :-)

The key thing with serverless backup is you need to have something on the server to put databases/applications into a known state (hotbackup mode for oracle etc). It really needs to be a fully integrated solution.

Veritas has a good solution for use with EMC symmetrix' and BCV's. I'm not sure about any other vendors offering fully supported solutions for array/san serverless backups?



dmcloon Wed, 01/31/2007 - 20:08


Where did you read "need two SSM's for a datacenter to datacenter backup" ?


inch Wed, 01/31/2007 - 20:58


Stephen mentioned using a SSM for serverless backup to a remote site... :)



dmcloon Wed, 01/31/2007 - 21:51

Hi Andrew,

You only need one SSM to do Network Accelerated Serverless Backup (NASB), even if the disk and media server is in local data centre and the tape is in a remote data centre.

Also, you dont need to connect any of the media servers, disk or tape directly to the SSM. You just need to have an SSM in the fabric that can receive the XCOPY commands from a media server and then read from disk and write to tape.

If the devices are in different vsans you can use IVR. If one of the device is remote the san extension method may be native fibre channel or FCIP.

The devices must be native fibre channel, ie you cannot connect a tape through a SCSI-FC bridge.



stephen2615 Wed, 01/31/2007 - 22:32

Hi Dallas,

Terrific info and exactly what I needed to know. If the price is right for this stuff, I definitely have a decent case to put forward. I could read your statement as:

One datacenter has the SSM.

Both datacenters can use the SSM as it will be native FC between them. So if each datacenter has an array and a VTL, the one SSM is all that is needed.

I just wonder how the licence works. If you have a 32 port SSM, do you pay for a per port licence to do the NASB. If I only use 8 of the ports, I have another 24 for normal switching.. well at least for now.

Someone at work sent the SSM info to Brocade and asked them if they could match it. The silence speaks for itself.

Next time you are down in the Nation's capital, I owe you a beer.


dmcloon Wed, 01/31/2007 - 22:57

Hi Stephen,

Your understanding is correct, particularly the bit about the beer(s).

You will need one STORAGE_SERVICES_ENABLER_PKG license for each SSM module. It is not port based licensing. The same license will also enable other SSM features such as SANTap. For example, there are 8 x DPPs (4 ports per data path processor) per SSM module and so you could provision some for NASB and some for SANTap, using the same license. Any of the DPPs you dont provision for intelligent services can be used for normal switching. BTW, FC Write Accel uses the Enterprise license.



stephen2615 Wed, 01/31/2007 - 23:13


Any time is a good time for a beer.

I would need the Enterprise licence (gulp) to do IVR as I have to come up with a solution that achieves lots and is future proof... My manager is interested in SANTap but I would need a good reference site for him to consider using it. I think virtualisation needs to be looked over SANTap in my point of view.


inch Sat, 02/03/2007 - 17:09

G'day Dallas,

Cool, I was under the impression that nasb via the ssm would work the similair to the santap stuff from kashya/topio.

What backup/recovery products can utilise this at the moment?



dmcloon Sun, 02/04/2007 - 17:03

Computer Associates Brightstor

Commvault Galaxy Bacup & Recovery

EMC Legato Networker

The above vendors have qualified their s/w with NASB. Veritas Netbackup works but is not qualified by Veritas, I believe due to non-technical reasons.

inch Sun, 02/04/2007 - 18:29

G'day Dallas,

I will do some investigating on the netbackup side. I would dearly love to have nasb via netbackup and ssm...



stephen2615 Sun, 02/04/2007 - 23:12

Boy am I getting confused now. Just to run this past you all.

If you are using CommVault as your backup software, then each server connected to the SAN can be configured as a Media Agent, and therefore can backup directly to the shared Virtual Tape Drives, reducing the network traffic.

So if we have say 100 servers attached to the SAN, we would need 100 media agents and I suppose a 100 connections to the backup library.

Serverless backup is a method of offloading backup procedures from a server so that the time ordinarily devoted to backup functions can be used to carry out other server tasks. Ordinarily, the amount of time that a server can devote to processing requests from applications is limited by the backup window - the amount of time that must be reserved for data backup. Serverless backup is a storage area network (SAN) solution that is designed to lead to lower hardware costs and improved time-effectiveness, scalability, and fault tolerance. A number of companies, including Legato, Veritas, EMC, and Computer Associates offer or are developing serverless backup products.

Does NASB remove this requirement? I really wish there was some decent white papers or road maps on this..

It seems that everyone can offer serverless backups but you need servers.

I have a meeting with the Cisco rep tomorrow. I hope he has some info.



dmcloon Sun, 02/04/2007 - 23:46

Hi Stephen,

Serverless backup does not mean you can do backups with zero media/backup servers. It means the CPU intensive data moving aspect is offloaded to a third part copy device, in our case it is the NASB component running in an MDS SSM module that does the copy function. The MDS takes an Extended Copy SCSI command from the media/backup server and then does all the hard work of copying the data from disk to tape. You still need the media server to schedule the backups, maintain databases of what/when was backed up, schedule restores,etc. Because MDS is doing the hard work you can manage with many fewer backup servers. For some large companies that might have say a dozen high end backup servers, they could reduce the number they need to run by even half by using serverless backup software (eg commvault) and Cisco NASB.




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