How to optimize the ReadyNAS performance

May 15, 2008 by yoh-dah
Filed under How-To's

How should I tune my ReadyNAS performance?

The ReadyNAS ships with conservative settings (the default mode) that provides the best compatibility and the quickest recovery in case of inadvertant shutdowns such as that caused by power outages. By simply using a UPS and a jumbo frames-capable switch, with a few tweaks of the performance options, you can easily configure the ReadyNAS for optimal mode, a more aggressive setting that can give your ReadyNAS a nice boost in performance.

Let’s look at the Performance options available through the FrontView web-based management system. Select the System → Performance option from the main menu. You’ll see:

If you have a UPS (make sure to use one from the USB UPS compatibility list) or if you don’t mind a longer boot-up time after a power failure, you can select the Disable journaling option. Doing so will boost your write performance by about 25%.

Next, let’s look at the Network options. Go to the Network → Ethernet tab and scroll down to the Performance Settings box. You’ll see:

If you have a jumbo frames-capable Gigabit Ethernet switch (it’s advisable to use one from the Network Switch/Router compatibility list if possible), select the Enable jumbo frames option. You’ll also need to make sure you’ve enabled the jumbo frames option on your PC or Mac driver setting and/or specify a MTU size larger than the default 1500. The ReadyNAS supports up to 7936 byte frame size, so for optimal performance set your NIC to at least this size. If your NIC does not support this exact frame size, don’t worry — the network drivers will negotiate down to the lesser of the two sizes.

Using jumbo frames can reduce the number of packets needed to transfer a file by a factor of 4, so performance can increase by about 15%.

What performance level should I expect?

There are two tests that the ReadyNAS Performance Lab uses to measure performance on the Windows platform:

IOMeter using 256 KB sequential block reads and writes on a 3 GB test file, and

Drag & Drop of a 3 GB file over CIFS, Windows default network protocol.

The tests are run on Windows XP Pro with Service Pack 2 (SP2) and Vista Home Edition with Service Pack 1 (SP1). [Note: Vista SP1 is highly recommended as it fixes major performance problems with remote share access.] A test file of 3 GB is used to overcome any advantages due to client caching.

On the Mac, IOMeter is not available, so we use:

Drag & Drop test of a 3 GB file over AFP. Mac users tend to prefer accessing the ReadyNAS over AFP as it provides better support for non-standard characters in filenames and the ability to maintain Mac-specific resource information.

We show the results in two performance settings — the default and optimal modes on the ReadyNAS NV+. Similar results can be obtained with the ReadyNAS Duo.

ReadyNAS Setup

ReadyNAS NV+
4 – Seagate ST31000340AS 1TB hard disks, 32 MB cache
RAIDiator 4.01c1-p1

PC Setup

Intel Pentium 4, 2.8 GHz
1 GB Memory
Windows XP Pro, Service Pack 2
Intel Pro/1000 MT GigE, Jumbo frame 9014 bytes

Intel Pentium Core™ 2 Duo, 2.13 GHz
2 GB Memory
Windows Vista Home Edition, Service Pack 1
Intel Pro/1000 MT GigE, Jumbo frame 9014 bytes

Mac Setup

Apple Power Mac G5, 667 MHz
1 GB Memory
OS X 10.5.2
Onboard GigE, Jumbo frame 7936 bytes

Network Setup

Switch: NETGEAR GS724TP

Router: NETGEAR WNR854T

IOMeter Results

Drag & Drop Results

How should I measure my ReadyNAS performance?

So now that you’ve seen what the ReadyNAS is capable of, let’s get as close to doing an apples-to-apples comparison. As you can see from the lab results, we use two tests — IOMeter read/write test and drag & drop test of a 3 GB file. You can elect to run one or both tests, in default and/or optimal mode.

For the drag & drop test, you can use a test file close to 3 GB in size. We select 3 GB to avoid any caching effects, so you’re truly measuring the network to disk performance rather than just network to memory. Simply time your drag & drop of your test file to a share on the ReadyNAS, delete the test file on your client, and time your drag & drop of the file back to your client. The first test measures the write throughput, the second test measures read throughput. Calculate MB/sec by dividing the number of seconds you get by the number of megabytes in your file.

You can use this number to compare with the results from our Performance Lab.

For IOMeter, following these instructions. Note that IOMeter will run only in Windows environments.

Download IOMeter from www.iometer.org.
Download iometer.icf, the IOMeter configuration file that we use in our labs.
Map your backup share on the ReadyNAS to V:.
Start IOMeter, and click on the Results Display tab.
Click on the green flag button at the top to start. It’ll ask you to enter a file name where the results will be stored. Click Save.
A 1 GB test data file call iobw.tst will be created in your backup share the first time IOMeter runs. Once the file has been created, you’ll see the Read and Write MB/sec as it runs each of these two tests sequentially. Note these two numbers.

You can use the numbers from #6 for your IOMeter comparison.

How do I troubleshoot my performance problem?

Due to different environments, you may not be able to achieve what we get in our lab. There are plenty of factors that may limit your performance. However, most results will be within 15-20% of what is expected, and some will even achieve faster numbers. If your results are off by more than 20%, check the following:

Update to the latest RAIDiator.
Update to SP1 if using Vista. Microsoft fixed Vista network performance issue with SP1 and you’ll likely see a huge performance gain by updating to it.
Check for network errors. Go to the Network tab in FrontView and check for errors. Bad packets and unrecoverable TCP retransmit errors are a sure sign that there’s something on your network causing performance problems. Here are some common problems and troubleshooting tips.
1. Marginal cabling. Replace cable(s) and see if the error counts continue to go up.
2. Incompatible or bad switch/router. Try setting ReadyNAS for static and going direct-connect. The network interface is auto-detecting, so you can use a straight or cross-over cable. Check the Switch/Router compatibility list to see if you device is listed or if there’s a known problem with it.
3. Wireless router. Try checking for router firmware update. We’ve seen cases where a bad router firmware caused performance degradation.
4. NIC on PC. If you have a Intel or Airlink gigabit NIC, try using that.
Disk fragmentation on the ReadyNAS. The ReadyNAS uses a file system that reduces the amounts of fragmentation; however, over time, constant deletion, creation, and modification of files can fragment your data. The only option at this point is to back up your data on the ReadyNAS, delete it, and restore. Unfortunately there is no defragmentation option at this time.
USB device causing connection timeouts. Try disconnecting USB storage and UPS monitoring cable from the ReadyNAS and see if the performance improves.
Marginal disks. Check the SMART logs in the Health tab. Check for non-zero ATA errors and re-allocated sector counts. They usually point to possible timeout conditions causing slowness.
Check System.log. Do a Download All Logs and check System.log. Sometimes this will give you some clues with low-level errors codes.
Delete any active snapshot. Snapshot will add extra delay to your write performance.
Disable firewall and virus scanner. See if that helps.
Close RAIDar and FrontView. Running them will cause extra scanning of device health every minute.
ReadyNAS 1100 slowness due to upgrade to RAIDiator 4.x. When upgrading to RAIDiator 4.x from 3.x, you may encounter slowness due to the way we are unable to apply the same hardware acceleration on the firmware. The best way to gain back the performance is to backup your data and do a factory default with 4.x as that will use large filesystem blocksize for faster disk access. For even faster performance, factory default with X-RAID. We apologize for this unavoidable situation.
Slow access over wireless or 10/100. The ReadyNAS employs an aggressive hardware acceleration for optimum throughput, however some wireless routers, wireless adapters, and 10/100 routers are unable to handle this acceleration. Try setting the MTU on the ReadyNAS to 1492 to disable this aggressive mode.
Check if BitTorrent is enabled. Even if you’re not fetching a file, there can be others fetching yours.

How can I get help if my ReadyNAS performance is still slow?

If you still see slowness after going through the troubleshooting steps above,you can post your request on the ReadyNAS Community Performance forum. It helps to mention that you’ve gone through each step of the troubleshooting guide, and provide the following:

RAIDiator version
Performance tab settings
Network switch model (and firmware version)
NIC on your PC
Number of disks and disk models
The read/write MB/sec numbers from IOMeter or drag & drop test.

Do remember that troubleshooting performance issue remotely can be time-consuming. Please avoid ranting (you’ll find folks more willing to help if you remain civil), and don’t expect miracles overnight. There are just too many combination of hardware and software that can have an effect on your performance.

We hope this guide helps and as always, let us know if there’s anything that you’d like to see improved in the future.