SLOW NETWORK BACKUPS (FAST LOCAL BACKUPS)

[acnsysadmin]

HELP! This is killin' me and I need all the help I can find at this point. Ive suffered through four weeks of CA's support in attempt to optimize my backups and my shoe seems to know more about Arcserve 2000 than these guys, still I have no real answer. This is what Im working with:

1 x Compaq Proliant 6500 (NT 4.0 SP 5)(Arcserve 2000 6.61 Advanced Edition Server SP2 w/ all patches applicable installed) with the 2000 Library Agent. Configured with a Compaq TL891 DLT Library. When I do a backup locally it flys (135.00MB/MIN), no problem there.

HOWEVER!

When I go out the the network to backup the other NT 4.0 systems it creeps a 0.26MB/MIN (Yeah really). After working weeks with CA support the rocket scientists identify that it is a network problem (Gee Really?) so I call in our Network Engineer and ping test our network silly. We did all kinds of tests, we would put the Arcserve Server and a test server on the same hub and still backup job preformance was slow. I did Registry edits, Network card (Full,Half duplex) settings. I switched out the dual port NIC for a single port NIC and attempted to backup another system with a single port NIC after learning that Arcserve somtines doenst work well with double port NICs. Our network is fine, or seems that way at least.

Where can I begin to look so I can get at least 100MB/MIN.

Help!

Rich Barger
System Administrator
703.893.9002 x74
703.856.1403 (cell)
703.893.4930 (fax)
ACN Energy INC
7926 Jones Branch Drive, Suite 500
McLean, VA 22102-3303
rich.barger@acnenergy.com

 

[fredf]

Rich,

Actually, your local backups don't seem very fast either. I get about 300mb/min on the local (Non-OS) drive. I used to have what I considered to be brutal network backups, but they were in the 40-50mb/min range. Check your block size, I believe Arcserve defaults to a 512-byte block size-it's in the registry, I believe the key is DefaultBlockFactor, check these forums or do a search on CA's site. Also, check your buffer size, read doc#16005 on CA's site as well. Once I tweaked all of these settings, I was still hard pressed to pass 70mb/min on 100MB Full (or half) connection. We recently installed a dual-port NIC in our server (Compaq, I believe it's a 6500 as well), and we teamed them. Now, the first NIC is hooked p at 100 Full, while the other on is hooked up at 10 half (on the same switch, haven't got the network guys to change the port settings). Nontheless, we now get 120-130mb/min regularily, and sometimes we get 200-300mb/min netowkr backups...

Hope it helps

Brian

 

[Peteksi]

The original poster's backup still seem slow for local. I've gotten around 300-500mb/min on a same-server backup using a single processor DL380.

Do you have the Arcserve Agent installed and up to date with the latest service packs?

I'd troubleshoot using the following steps:

1) verify your local backups fly. I get anywhere from 250-400MB min average backing up several GB of data on local.

2) perform a normal network copy from host to backup server (ie using windows explorer). If you can copy say a large directory of say, 1000 or more files and 500mb in say, 5-6 minutes, thats pretty decent 100mb full ethernet performance.

3) if anything in #2 looks bad, that's a good start. Check for alignment errors between network port and network card on switch (esp if cisco).

4) any 100mb full ethernet connection to Arcserve with an agent should go AT LEAST 100mb/min over a LOT of data. This is because the agent packs up the date before sending. I've gotten 500mb/min over a single 100mb ethernet connection from a server running an agent. In fact, I can send you the logs and you can read em and weep. I'm still amazed. Arcserve though a POS for functionality and reliability is supposedly the fastest such software out there...

good luck.

Peter Turek
Sysadmin
pturek@sempratrading.com

 

[Electro]

Hey Rich,

The others have made some good suggestions for you. I also suspect you are having some strange network problems based on your comments.

1) When you connected your servers across the hub did you ensure both servers were set to HALF duplex? Remember - typically hubs cannot handle FULL duplex.

2) Check your Switch / Router configuration and ensure that your ports are set 100 MB Full Duplex - MANUAL setting, NOT Auto Negotiate. Cisco equipment is specifically bad for this where the server is set to 100 MB Full manually set and the switch / router negotiates at 100 Half.

3) How much memory in your server? Memory is a big factor with Arcserve buffer size and there is a registry tweak you can do to increase the buffer size hence better throughput. Check the following article for improvement in these areas

http://support.cai.com/techbases/as61/10015.html

Good luck and let us know how you make out.

Thanks,

Darryl Brambilla
EDS Canada

 

[ZmanZONK]

Similar network
Cabletron Switch
Proliant DL380 800+MB RAM
100MB/Full on ports/NIC (single port)
Arcserve 6.60 for Netware EE SP4
ALL Netware 5.1 SP2A
ALL Proliant servers of various versions
Exabyte 440 Tape Library, EXB-8900 tape drives (2)


Symptoms
Throughput seems to vary depending on the volume? For example, one server backups up at 100mb/min on SYS, but only 12mm(now 21mm see below) on VOL1. Host is 100mm+ on both volumes (compare operations and Arcserve database are at 200mm+)

The servers are in the same Novell container as the backup server and on the same segment in the same server room. Yet throughput varies considerably between volumes of approximately 8 servers.

Tested Computer Associates Suggestions:
Packet Receive Buffers (PRB) and Directory Cache Buffers (DCB) ... they had a nominal affect on the problem volumes.

Unload antivirus (McAfee) - no improvement.
Disable File Estimate - no noticeable changes
Disable Compare - no noticeable changes
TCPIP.NLM version - 5.22y

BULLSEYE - one great suggestions was to increase the MaxConcurrentDiskCache Writes (default=750) to 1000. My current setting was at 500. This improved throughput from 12MM to 21MM (80%). See SET Parameters/File Cache.

I have reservations about using the Arcserve Push Agents because in the past I had indentified them as being the source of dropped connections on my 100MB ethernet LAN. Disabled push agent = no dropped connections. Enable push agent = consistent dropped connections. I will try again with most recent version and keep my fingers crossed.

This does not explain why some servers can backup over 150mm and others at 12mm?

I found the faster servers were not located on one particular card on the switch. Moving servers off this card has made a noticable difference.

Also, in my experience it is very important to look at volume backups that span many files and a lot of disk space ... prefer to monitor FULL backups versus diff or incrementals.

Some really good advice here:
monitor copying files in Explorer to determine network bottleneck
CA doc #10015 for isolating other subsystems
dual port NICs
Perhaps the upgraded Push agent?
Similar network
Cabletron Switch
Proliant DL380 800+MB RAM
100MB/Full on ports/NIC (single port)
Arcserve 6.60 for Netware EE SP4
ALL Netware 5.1 SP2A
ALL Proliant servers of various versions
Exabyte 440 Tape Library, EXB-8900 tape drives (2)

 

[Guest_imported]

You could look at getting more RAM.
I noticed my network AND local backups slowed down dramatically on our server when I decreased the amount of physical RAM.