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Slow Backups 3

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bizzyb

Technical User
Jan 13, 2003
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I have several similarly configured Dell Servers with same slow backups. Running ARCserve 2000 Advanced Edition on Windows 2000 Advanced Server, with backups performed on local machine to Sony AIT3 tape drives. According to specs, the Aic-7899 controller and AIT tape drives should allow for a min of 12MB/sec but the best we get is about 350 MB/min. All firmware and drivers are updated. Now looking at ARCserve. Any suggestions? What else could I look at?
 
Greetings, Ronnie.

I am glad that you have been able to make progress. In regards to the Citrix machines....again, go back to doing a FileSystem type of backup. If you are getting reasonable results the problem is not in the LAN/NIC portion. If you are, then the problem could be in the LAN/NIC or on the source machine itself. Unfortunately, I know of no magic bullet to help, other than trying to narrow it down.

As for the 1,300 MB/min, I am green with envy, heh. Good luck with the Citrix machines!

Also, my experience stops with AS2000. Haven't gone to BS (no pun intended) 9 as of yet, but hope to soon.


Greetings, NorthstarDave.

I have to agree with Ronnie, check the drivers.

After checking the drivers, and even though it sounds like a waste of time, I would disconnect all the SCSI cables and reattach them. The reseat might help a less than good connection. Also check your termination. Make sure that it's good on both ends of the bus.

And make sure nothing is turned down in the SCSI BIOS that would drop the data rate.

But, be encouraged, at least you know where to focus your efforts, and I am sure you will zero in on the culprit soon enough.

On a side note, "Double-plus-un-good"? A 1984 reference?


Greetings, TomMartino.

Off the top of my head, I forget the exact registry key, but (in AS2000) there are device entries, and you can add/change the value for the block size under this key. CA technical support has references to the registry changes that are necessary to do this in detail.

Regards,

Don Osicky


 
As far as I know the drivers are up to date. I went to both Dell & Adaptec & got the latest ones. Maybe they need to put out some "later" versions. ha!

I will try the cable shuffle. The scsi card has its settings for what I would assume is maximum throughput although the next time I reboot the server I'll grab them & post them here. Termination should be fine but again I'll double check it.

Double-plus-un-good is in fact a 1984 reference. ;)
 
Hi guys, I am a newbee to tek tips, and to proper back up operations. Foland, i think 350 mb min is great. I am trying to backup 3 drives on a dell poweredge 4400 (running win2k server), raid 5, with arcserve 2000 workgroup edition and i get about 350 MB/min too. But my problem is that when i try to back up a mapped network drive(about 10 gigs of data on a client running win2k) i get an embarrasing 15.5 - 48 MB/min with about 10+ hours to create the backup just for that mapped drive. Can anyone please help?

Minor detail, this giant poweredge server with raid 5, and 3 scsi hardrives, and 2 800Mhz CPUs has only 256 MB of RAM.

Gilbert
 
We have been experiencing poor performance with Arcserve Ver. 9 on Win2K while backing up NT 4.0 machines with the new agent.

After numerous calls to CA concerning this and their useless troubleshooting skill where they blamed everything on our network I decided to research this problem myself.

After looking into several user forums I came upon a suggestion to alter the TCP window size. After reading this and researching the steps to change the size I performed the change. After rebooting I connected to one of the servers that was showing the low through put and I found that I was now get almost 3 times the through put.

Here is what I did:
FOR YOUR OWN PROTECTION PLEASE BACKUP YOUR REGISTRY BEFORE MAKING CHANGES

Using Regedt32.exe locate the following registry key

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters]
Find the NIC that you are using for backups

Add New Value = Value Name: TcpWindowSize
Data Type: REG_DWORD (DWORD Value)
Value Data: 0 - 0xFFFF (default = 8760 for Ethernet) I used 31012. Enter it in Decimal format.

I hope this helps in some way.


Regards
Paul


 
I dont know if anyone has posted this before (too many posts) but in arcserve 2000 if you disable file size estimates it reduces backup times by 30% - 50% on local and network machines

Hope it helps

R121
 
I was wondering if anyone experiencing poor through-put tried the TCP Window resizing that I mentioned? We have gone over a week with the changes and the backups are running so much better. Originally our NT 4.0 servers were backing up at 20-80 MB/per min. with the new agent, we are now averaging 200+ MB/per min. 620mb/min on Win2K machines. I told CA about this and they said they had never heard of it and they have no reports of poor through-put with the new Arcserve versions or Brightstore.

I found a GUI utility that does the change instead of you fumbling through the registry, it's called WinGuides Tweak Manager. You may download the Demo here:


It's nice utility, easy to use. Works well on NT/2000 and 2000 Server.
 
Greetings, Gillogist.

I would try running the backup through the ARCServeAgent, or through the network, not a mapped drive.


Greetings, Nightwatch.

Aye, I have tried the TCPWindow dance in the past. In all fairness, I can't really blame CA for this one though. It is really in the domain of the network configuration, and their catchall reaction is "assuming that everything is setup properly"...and this is part of that. That's why there are system administrators. ;) There are a plethora of items that they could run through if we were to ask them to be experts on everything hardware and OS related. Just off the top of my head would be why not go to a gigabit ethernet network? That would greatly improve performance...adn the tweak you supplied IS to tweak the network.

Not trying to be a smartass, just trying to be fair, and give the devil (CA) his due. Taking that into consideration, I do agree with the statement "and their useless troubleshooting skill". I've been on the receiving end all too often, and can sympathize.

Regards,

Don
 
Thank you IggyPop for your reply. I tried to back up through the network instead of the mapped drive and I got the same throughput (about 15 MB/min). I know that this is some sort of a network configuration problem. It might be a DNS issue but i don't have DNS errors in my log. I don't know exacly what you mean by backing up through the arcserve agent. Would you mind explaining?

Thanks again for your help.

Gilbert
 
The first thing I would check if backing up through the network is to make sure you are using the manufacturer drivers for the network cards. Once that is done manually set the card and the switch to the fastest allowable speed, preferably 100 full duplex or gigabit. If this doesn't help and you are running anitivirus software then run a pre and post command to stop and start the anitivirus software during the backup process and you should see a big change. Keep in mind you are only gonna backup a max of about 36gig per hour over a 100 mb connection and somewhere around 80 gig per hour over gigabit provided you have good switches...
 
Hi,

I am using ArcServe 6.6 and I too is experiencing slow back ups. I tried what NightWatch had suggested but I did not find the registry entry he had mention (or am too dumb to find it)regarding NIC. I was only up this level HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Services\Tcpip\Parameters then I could not find any entry about NIC.

Could anyone help me? Thanks.
 
Hsilva,

If you send me your e-mail address I'll attach the key changes for Win2k and NT Server 4.0.

You simply have to merge them into the registry with a right-click.

Regards

Paul
 
Nightwatch,

You may email me at hsilva@dairy-farm.com.ph.

Thanks in advance.

Henry
 
The value in question can be HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Parameters\TcpWindowSize, or in other places as below:

Specifies the initial "window" for TCP connections. One side of a TCP connection tells the other side how much data it can send before receiving an acknowledgement. This solves the problem of having to acknowledge every transmission.

The larger this value, the higher the performance, but at the cost of more memory being used per connection. Windows NT 4.0 used a default value of 8760, whereas Windows 2000 doubled that to 17520. This means that Win2k will transfer bulk TCP data faster than WinNT, but use twice as much memory for buffering each TCP connection.

The maximum size of this parameter is 64240 for WinNT and individual interfaces on Win2k.

For best performance, this value should be a multiple Ethernet Maximum Segment Size (MSS).

On Win2k, this parameter can also be set on a per interface basis using HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\Tcpip\Parameters\Interfaces\<interface>\TcpWindowSize. On WinNT, this parameter is set on a per interface basis using HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\<interface>\Parameters\Tcpip


On Windows NT, you can generally find out what <interface> shoud be by looking at what keys are in HKEY_LOCAL_MACHINE\System\CurrentControlSet\Services\NetBT\Adapters
 
Monster,

What would be the maximum windows size that you would use for a 2000 server? I've configured mine for 31021.

 
On the Arcserve 2000 CD under the utility folder there is an application called, sharemem.exe. You can run this utility to specify how much memory is dedicated to a backup/restore job. Before using the utility to dedicate memory you should note how much each asrunjob.exe process is using under task manager, during a regular backup or restore. If you are already maxing out your memory it will do no good to set a dedicated amount. We were running at about 110 MB/min with a total of 256 MB in our backup server. We added an additional 512 MB and dedicated 256 MB per job (we have 2 separate jobs that run each night). Now we can get anywhere from 300 to 600 MB/min, depending on the class server we are backing up. Please note that you should divide the amount of free memory by the number of concurrent jobs you will run. Example: If you have 500 MB free and you run 5 jobs, you should enter 100 MB in the sharemem tool, not 500.
 
I have Sharemem, CA sent it to me. I cannot get it to work with Brightstore V.9 I get an error telling me that the Tape Engine is Not Started, when it is. I don't think this app is designed for Brightstore.

Paul
 
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