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Tyson0317

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Gig-E is not fast enough...

Hi All,

We have 2 servers, one running 2003 SBS, the other 2003 Standard (member server on the domain). The SBS box performs backups nightly via Backup Exec and pulls ~200GB of data per night from the 2003 Std box. The problem is, due to the bottleneck in the speed of the network connection between the 2 servers, the backups are taking WAY too long to run.

The obvious solution is to switch from FULL backup sets to INCREMENTAL, but I have had bad luck with that in the past, and REALLY want to keep my FULL nightly backup sets.

We upgraded the NICs on both servers and the ports on our switch to Gig-E, thinking that it would speed up the backup process - we really noticed maybe a 20-30% increase in data transfer rates... Not good enough.

The next obvious choice is Fiber. However, we do not have a fiber switch and fiber modules for our switch are $$$. How much of a realistic performance gain will I gain from Fiber Vs. Gig-E? Also, with Fiber, is there any way to just link the 2 servers together without having to use the switch - kindda like using a cross-over ethernet cable - does fiber do that?

Another option is to throw another pair of Gig-E cards into each box. However, I am not sure how to make 2 cards work on the same network together. I know that there is got to be a way - Network Load Balancing Service maybe? Never used it - a short how-to might be helpful. If adding a second Gig-E interface will double our transfer rates, it would be a sufficient solution to our problem for at least a year.

What do you guys think?
Avatar of Lee W, MVP
Lee W, MVP
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I think you are going in totally the wrong direction.  

Nightly 200 GB full backups is, in my experience and opinion, VERY INAPPROPRIATE.  And I don't know who told you to do incrementals - that's far from appropriate as well.  You should be doing DIFFERENTIALS.

As for fiber, that depends on what kind of fiber connection.  Common fiber is 1 Gbit - so if you already have gigabit ethernet, then fiber is not going to do you any good.  Now, you could consider 10 Gbit fiber... but that's exceedingly expensive and not sold and compusa and staples.

But even if you got 10 Gbit fiber, you would not see that kind of throughput.  Even SCSI RAID 0 can only feed data at 320 MB/Sec MAX which is roughly 2.5 Gbit.  And that maximum is technical - actual will probably see less - possibly much less, depending on what you are actually backing up and how fragmented the drive is.
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Lee W, MVP
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LOL - are you sure it's your network speed that is the bottleneck here?

I'd think it boils down to your choice of operating system, but I could be mistaken.  Have you analyzed your traffic flows (preferrably from an intermediate device, like a managed switch) to confirm that the network is indeed saturated?

>How much of a realistic performance gain will I gain from Fiber Vs. Gig-E?

If my assumptions are correct, not much.

Also, why do you have SBS installed on your backup server?  If you're looking for as much speed as possible, don't you want a box that is dedicated entirely to backups?

Looking forward to your reply,
-Jon
I skimmed leew's document, and was reminded of the RAID suggestion - for the $$ you're contemplating, you could easily set up a raid array with hot-swap drives and be done with it - you just have to make sure you have a few spare drives around so you can swap out if things start going bad, or (if you're worried about the lightning scenario) actually just swap out drives every night - I'm sure a decent RAID controller could easily clone a 300G drive nightly.

Cheers,
-Jon
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tim1731

Lets look at what and how needs backing up

SBS 2003 How is it set up if

C: just OS
D:Exchange + SQL + Rest of SBS setup
E:exchange stores
F:User + main data

I use ntbackup for exchange follwed by v2i on c:,d:,e (ntbackup = 32 mins V2I for 3 drives 47 mins across 100mb network) I take a full image each night but a rolling 5 the ntbackup flushes the logs and with powercontrols I can restore any emails without any problem and within normal working hours.

On the f:drives we use EMC® RepliStor® SMB Edition this will copy the whole drive once and after that only the changes in each file in real time at the byte level (cost $1000) also will copy to a nas offsite over vpn.

1.So if server goes down I can restore within I hour
2.Any you know that email from jan last year within 15 mins
3.the main files are offsite as well as on another server still with there nt permissions so change the login script to point to new locations



Just remember - RAID is NOT backup - RAID is redundancy.  If a file gets corrupt or deleted or modified, the building burns down (or some other natural (or unnatural, beyond your control disaster), or the file system itself corrupts, RAID does you no good.
If you only saw a 20-30% improvement with GE, you should instead take the time to isolate the performance problem that's holding you back - what makes you think XE will go ANY faster for you?  You probably have disk I/O limitations that are holding you to 200-300Mbps, so XE won't buy you anything except draining your wallet.
Also with EMC® RepliStor® SMB Edition use can state with network card to use IE add other card in each server and connect using cross over taking this traffic off main network 100mb full would be enough
What hardware are you running this on? I use BackupExec and get over 600MB/min.
Just because you have a GigE interface on your system does not mean that your system is capable of sending/recieving at GigE speeds.

What type of systems are you using? Bus speed? PCI? PCI16? etc .....

You need to provide more information on your architecture.

How long do the backups take? Are you doing anthing else on the systems/network during this time?

200 gigabytes of data = 1600 Gb (giga bits of data)

Remember that is 200 GB of application data, is not network through-put , which would be much higher.

harbor235 ;}
200 GB data, going at 1000 Mbit, that's 125 MB/Sec - theoretical Max.  200,000 MB/ 125 MB = 1600 Seconds = 26 minutes, 40 seconds.  That doesn't fit in your backup window?

Of course, there's IP overhead... so lets say it's 20% - 200,000 MB/100 MB = 2000 seconds = 33 minutes, 20 seconds.

If your backups are taking longer, then you need to re-examine what you're backing up and the other abilities of the system.  But as I first said, if your are backing up a lot of small files, then backups will go slow and there's not much you can do about it - other than implement a proper backup scheme.
By the way, 200 GB over a 100 Mbit link should take 266 minutes - 4 hours 16 minutes.  Or, with IP overhead, figure 5 hours 33 minutes.  Over your typical window at night - if we assume 11pm to 7am is typically ok, that's 8 hours - meaning a maxed out connection at 100 Mbit will STILL BE SUFFICIENT to cover your needs.  So in summary - it's NOT your network connection that needs upgrading.
I agree its the servers


harbor235 ;}
agree it is the servers

just wanted to throw in that if the gig adapters are PCI and not PCIexpress you have a max bit rate due to the computers bus of about 312 megabits with overhead.  PCIE can do gig.

I don't think you can transfer data from one machine to another (assuming contained on a hard drive / array) at gig speed using consumer grade products.  There is going to be a bottleneck somewhere, and it is unlikely to be the network wire speed.  I was asked recently to consult on a case where the network slowed down after gig upgrade.
What exactly you are Backing up..
You said you are using the Veritas Backup Exec.

Veritas Backup Exec will be slow when you are backing up the SQL Server database and Exchange Mail Boxes..
Go to the Veritas Backup Log reports and see which data is taking long time...
How much is your Exchange data?? and are you backing up individual mailboxes??


regards
naren