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10 Tips For Boosting Network Performance
snydeq writes "InfoWorld's Paul Venezia and Matt Prigge provide hands-on insights for increasing the efficiency of your organization's network. From losing the leased lines, to building a monster IT test lab on the cheap, to knowing how best to accelerate backups, each tip targets a typical, often overlooked IT bottleneck."
I learned from the BOFH that the fastest backups are written to /dev/null.
"This post contains words, known to the State of California to cause thought. Wash brain thoroughly after reading."
Plug wires in again in a more colorful way.
It's a small world and it smells funny; I'd buy another if it wasn't for the money; Take back what I paid (SoM)
Just give Eric Schmidt a call, tell him you have nothing to hide from his company or the government and they will replace all your machines with shiny new Google Chrome OS based "Net tops", put all your data on their servers, give you a brand new direct fibre optic connection to their nearest office and all they want in return is the ability to meticulously sift through your data in order to find the best way to bombard you with text-based ads.
Everything is more shiny with Google.
What reason is there to run T1/T3 anymore? I know, by definition, the regulation over T1/T3 guarantees reliability. I have dumped T1's and switch to 2Base-TL (aka Metro Ethernet) and it is extremely reliable. For me, the "more reliable" argument doesn't hold much. The latency is very, very good -- often below 10ms. Even if the network goes down, I can afford some sort of backup link. I'm paying under $1,000/month for 10mbit (symmetrical). The footprint for 2Base-TL is pretty good because it is based on DSL technology. It doesn't have the reach that T1's have, but it isn't bad. The big difference is that is spreads the signal over multiple pairs of wire (in my case, 8 pairs) instead of a single pair.
If your company has T1's, shed yourself of the "regulated" links and check out 2Base-TL. You will be glad you did.
once I told a coworker about emule. He downloaded and installed it. The next morning the CFO comes to me.... "Have you ever heard about emule"...the infastructure was screwed up, but instead of fix it they waited for p2p to bring the network to it's knees. The best way to test a network is to see how many simultaneous p2p connections it can handle before crapping out. Needless to say there were some consequenced for that employee.
It depends, we have some sites that have done very well with cable providers on business class accounts (I assume those that have separate channels for business class), and less so with others. Our biggest problem has been the lack of any teeth to an SLA when we did have problems, which is why I would never move our HQ which has nearly half our people and which hosts remote access for the rest. For a remote office where they can always fall back to 3G tethering if they have an outage for a day or two and use our Citrix farm it's a great way to get bandwidth on the cheap.
There are 4 boxes to use in the defense of liberty: soap, ballot, jury, ammo. Use in that order. Starting now.
I look at the tapes, and yes, I know how useless they'll be in about 3 years time, we'll have migrated to a new system that isn't compatible with this. I look at the backup tapes from 1999, and how we don't even have a tape drive for them anymore, but should we need to access them we'll probably hunt them down.
What kind of disks are you talking about? Well I need over 1TB of space per backup, at the end of each month, 4 different 1+ TB backups to be stored indefinately. So I can't use floppies, CD/DVD/BRD...
Because Hard Drive Disks go through different mediums too you know, I can't plug my SCSI into a SATA. I am not entirely sure that any hard drive I use today will be accessible 10 years from now. And lets look at the prices for a 2TB hard Drive (since that'd be what I'd need). Let's say I get lucky and get them for $100 each. Tapes I can get for $30.
By using tapes we get the size we need, though the speed is slow, for the right price. Saving almost $3000 a year by using tapes.
2.Ban Microsoft shares
3.Ban NFS
If you ban CIFS and NFS, what's left? Sneakernet has great bandwidth, but the latency sucks and it's a bitch to search.
Socialism: a lie told by totalitarians and believed by fools.
An 800GB Native / 1.6TB Compressed LTO-4 tape costs $35. If you don't deliberately choose a ridiculous comparison, tapes really aren't that expensive.
You sound like someone who has never been responsible for long term backup storage. Stuff isn't just thrown on a tape and stored offsite for years. Responsible DR requires you to constantly be shifting all your long term storage onto new methods, constantly. You wouldn't have MDF hard drives with valuable data on them, or even legacy data as all that data should have been MOVED and VERIFIED onto current media.
--- I do not moderate.
... and if you think it is about latency you are mildly retarded, as are the writers of this general knowledge article.
Leased lines in general have better SLAs but that isn't even much of a point anymore as they cheaper products "claim" to have similar ones. The difference here is how good is that business class dsl/fiber support at 2am? What are the odds they are actually going to be willing to send someone out to the telco closet right away if there is an issue? You buy leased lines because you need *real* support of the SLAs... not this, "well we were down for 5 hours, so how about we credit you a day off!" bullshit.
It's really scary for what passes for "good advice" these days.
--- I do not moderate.
Interrupt Moderation = Disable
Here's a real tip, disable Interrupt Moderation on your Network Adapter Cards to achieve greater bandwidth, as much as 100%+, and lower latency (the two measures of network performance) at the expense of processor utilization due to more hardware interrupts that have to be handled.
Instructions: In Windows open up Control Panel, Network and Sharing Center, click on Change Adapter Settings, open Properties on your Local Area Connection (sometimes #2, #3, or something if you have more network cards), click on the Configure button, then the Advanced tab, select Interrupt Moderation, change the value to Disabled, while there look for any settings with the word Offload and enable them all, and then click the OK button to make the changes. This will restart your network card driver and make the settings effective.
Most network cards from popular manufacturers such as Intel, Broadcom, Realtek, etc. hold network packets in a buffer until enough time goes by before raising a hardware interrupt and telling the processor, operating system, and network driver that there are packets waiting to be serviced. By disabling Interrupt Moderation you instruct the network driver and card to raise the interrupt every single time a packet comes in, thus making your processor service the network card much faster thus decreasing latency on the packets held in the buffer and also increasing bandwidth by allowing more packets to flow through faster. This increases your processor utilization by a significant amount 10-30% but if you have a recent dual, quad, hex, octo-core processor and recent network drivers that are multi-threaded with multi-core support and have Receive Side Scaling support then the increased processor utilization is negligible to your computer and if you are running a network server then network performance should be a priority anyway.
I have personally seen and tested corporate and home LAN environments using Fast Ethernet 100 Mbit/s (~11 MByte/s) go from slow 6-7 MByte/s to 10-11 MByte/s throughput, and Gigabit 1,000 Mbit/s (~100 MByte/s) go from ~30 MByte/s to 95-98 MByte/s speeds due to these changes. No other network driver setting had as much performance impact as Interrupt Moderation.
IEEE 802.1AX (aka 802.3ad, Cisco EtherChannel)
For advanced network performance improvement look at link aggregation (channel trunking, link bonding, etc.) using the IEEE 802.1AX (aka 802.3ad, Cisco EtherChannel) protocol support in your Intel and Broadcom network adapters using their Advanced Configuration Utilities on your servers to bundle from 2-8 Ethernet network adapters into one trunk to increase your performance. Just tell your network administrators to enable those features on your ports and find out if they are able to do it if your links are going to the same switch or if they have virtual switching enabled in case your links span switches. Just think about 4 x Gigabit performance if you bundle all 4 NICs on most servers.
NetCPS
You can test your own network performance with this simple but great utility called NetCPS. Just be sure to disable Interrupt Moderation on both of the computers on your LAN that you will be using for the performance testing otherwise you won't be able to achieve these numbers if one of the computers can't handle the data as fast as the other one. Try it with your laptop and desktop for example.
NetCPS - is a handy utility to measure the effective performance on a TCP/IP network.
Just execute "netcps.exe -s" on the listening system and then do "netcps.exe computername " on the other computer to use the utility to test the throughput bandwidth. For Gigabit you can use the "-m1000" switch to increase the transferred amount to 1,000 MBytes instead of the default 100. Below is an example.
Nice informative post, interrupt moderation sure sounds interesting. Link aggregation, however, is not as useful as it sounds for the following reasons:
1. Hardware link aggregation (link aggregation supported in silicon) works by hashing, not by distributing packets evenly across all links that are aggregated. If you can spare some time to ponder about this for a moment, you will be able to see why hashing is used. In real life situations, 4 x 1Gbps links aggregated together never equals 4Gbps throughput.
2. If link aggregation is handled by the software (which is most likely the case if aggregating multiple NICs on a server) then all it really provides is redundancy. It is very difficult for an average server to process 1Gbps of incoming traffic, let alone generate 1Gbps of worths of traffic. Not to mention the read/write speed of the storage device(s) used in the server.
(Unless it's using PCIE SSDs in RAID configuration, which would be very interesting and I am dying to find out the throughput of such a configuration!)
For once I actually know what I am talking about, so maybe I should have created an account before posting this one.
...and that's why offline HDD storage should equally be in RAID format.
That said, I worked for a D2D disaster recovery provider, and one time only we had issues recovering data from an archive drive due to disk failure. Suspicion was the drives were pulled before the job actually finished.
Now, HDDs sitting idle have a bit failure decay measured in years. Worst case, if the drive mechanism failes, the platters are still fully readable and easily recovered. Data being pulled from legal hold usually has no timeframe recovery requirements (unlike disaster recovery, there's no SLA for court requests of data), and worst case, HDD repair is a viable option.
Tapes have a bit failure rate measured in days, typically 30 for most tapes, and once data decays from the tape, it can not be recovered. Also, most typically, a tape recorded on one set of drives can not be read by another set of identical drives. often, the very same drive has trouble reading its own tapes if they've been shuffled out of the building and back in months later. I used to do an experiment in a classroom teaching DR methods where I'd perform a backup and bit-level verify (and only 3 in 10 pass verify at the bit level, but assuming it passed I'd continue, then I'd take the tape out of the drive, drop it just 6 inches to a table, flat, then put it back in the drive and repeat verify, and it would predictably fail 100% of the time. I'd repeat that with a hard disk backup of the same data set, let each person in the room drop the drive from shoulder height to the floor, then repeat the verify, and I never once had a failure (though once I had trouble getting the drive back in the tray slot).
There is no contest in life for which the unprepared have the advantage.