Elliott C. Back: Internet & Technology

In this post, I’ll be reviewing a brand new Synology DiskStation DS1511+ NAS equipped with five Hitachi Deskstar 2TB 5K3000 drives configured in RAID5. For comparison, I’ve also written about the Gen 1 Drobo’s performance as a NAS before (it tops out around 20MB/s), and own two of them at home. While the Drobos allow you to build mix-and-match RAID arrays, they are slow, take forever to rebuild, noisy, and hot. I am hoping the DS1511+ will remedy all of these issues.

Read more about the DS1511+ specs here

Network Base Configuration

The Synology NAS is using default MTU of 1500, connected to a Gigabit Ethernet Switch on LAN2. Testing with iperf shows a good gigabit connection between my PC and the NAS of around 885Mb/s:

Big_Bug> iperf -s
————————————————————
Server listening on TCP port 5001
TCP window size: 85.3 KByte (default)
————————————————————
[ ID] Interval Transfer Bandwidth
[ 7] 0.0-20.0 sec 2.05 GBytes 882 Mbits/sec
[ 6] 0.0-30.0 sec 3.09 GBytes 885 Mbits/sec

In megabytes per second, we can transfer 110.625 MB/s. As you will see, this is actually slightly lower than the performance of the RAID array.

The Hard Drives

How fast are the triple-platter 2TB deskstar 5K3000s in RAID5? It can do a very reasonable 125 MB/s in unbuffered pure-disk performance:

Big_Bug> hdparm -t /dev/sda
Timing buffered disk reads: 374 MB in 3.01 seconds = 124.22 MB/sec

Benchmarking File Copy from Windows

To test how fast I can transfer from my PC to the NAS, I’ve created a 4GB binary file:

C:\Users\Elliott Bäck\Desktop>ls -l test.file
-rw-rw-rw- 1 Elliott Bäck 0 4693544330 2011-04-19 20:00 test.file

Copying this file in Windows 7’s explorer took just 50.5 seconds. Doing the math, this gives us an average write rate of 88.63 MB/s. How fast can we copy it back? It took 71.6 seconds, for an average read rate of 62.51 MB/s. Both of these number are going to be constrained by how fast my desktop PC’s Intel SSD can read/write. I also tested using Java and writing a RandomAccessFile with a ByteBuffer, which achieved 95MB/s write and 97MB/s read on a 1GB file.

Reliability & Temperature

You just need to open up the storage manager on the Synology DS1511+ NAS to see what a beauty it is, giving you a full SMART status readout on all your physical drives, as well as their temperatures. Even after running through my benchmarking, the drives were only 34^° C warm:

Conclusions

At nearly $900 for the NAS itself without drives, it’s pricey. But plugged into a Gigabit ethernet, the DS1511+ from Synology is also fast, cool, and quiet; the three things you want most from a NAS. Featurewise, it has a glorious UI, media servers built in (which I don’t use) and expandibility from 5 to a maximum of 15 drives. I anticipate phasing out my Drobos, with their proprietary technology, for the Synology NAS, which runs on open-source plain-vanilla linux.

I’m a huge fan of the massive (but slow) bulk storage devices made by Drobo. I own two of the Data Robotics Drobos. They’ll save you from losing data if a single drive fails, and a single enclosure can hold 4 drives for up to 8TB of storage. Sure, they’re relatively slow compared to a single drive, RAID, or an SSD, but they’re perfect for an external hard drive for home storage.

And now they’ve upped the ante with the Drobo Pro, an 8-bay enterprise version of the Drobo.

There’s a new “Dual Disk Redundancy” option will spread the data out such that the Drobo Pro array can suffer two simultaneous drive failures without any loss of data or interrupted service. You can even toggle this option on and off without having to rebuild the array. There’s also new connectivity via gigabit ethernet (iSCSI) as well as the older FireWire 800 and USB 2.0 ports. Linux, Windows, and Mac are supported, on NTFS, HFS Plus, EXT3 and FAT32. For more details, check out the data sheet.

You can buy one now for $1,300 from the Drobo store, or $900 if you exchange two old drobos for the new shiny model, something I’m horribly tempted to do right now.

Gizmodo has a new review of the Western Digital Sharespace 4TB personal NAS product that just came out, and it’s absolutely glowing:

Western Digital’s ShareSpace Storage is a steely, cubular vault of NAS with fast Gigabit ethernet that brings enterprise-level centralized storage down to the small business and deathcore nerd space.

For $999 you get 4TB of storage (2.66TB actually free w/ RAID5), sluggish transfer speeds (10.5MB/s writing and 12MB/s pulling data), three USB ports, and Gigabit ethernet. You could get a faster Drobo for $100 more. And, in my tests, the better looking Drobo gets 16MB/s, and is also hot-swappable. You can buy the enclosure and put in 1.5TB drives to get a 6TB rig if you are so inclined, something that’s less possible with the prepackaged WD NAS solution.

I’ve had bad experience with Western Digital internal/external hard drives; they just die on me (and all the friends I know) a lot. But, I don’t own a WD NAS, so if you have one, let me know your thoughts!