|NETGEAR ReadyNAS NV+ v2 NAS Server|
|Reviews - Featured Reviews: Network|
|Written by Bruce Normann|
|Tuesday, 31 July 2012|
Page 11 of 15
1GB RAID 5 Test Results
If you've got more than three HDD spindle to put in play, it makes sense to use one of the more advanced RAID configurations. RAID 5 is one of the most popular setups, primarily due to the balance it exhibits between capacity and redundancy. Not surprisingly, most NAS units that can support more than three HDDs also support RAID 5, so it makes sense to use it for test purposes. Most NAS products that can support RAID 5 go beyond the minimum number of drive bays, to a total of four, so that is the number of drives that I typically use to test with, even though I could get by with only three. The NETGEAR ReadyNAS NV+ v2 uses a proprietary disk management tool called X-RAID2, which provides automatic volume expansion and RAID migration. You can manage the RAID configuration manually, but the X-RAID2 process is a lot easier and doesn't require you to migrate your data off the NAS during transitions.
The results for RAID 5 read testing show that the ReadyNAS NV+ v2 is optimized more for this configuration than for a single disk. It catches up to the more costly QNAP units in a big way, racking up a 93.5 MB/s average read speed with 1 GB files. It can't quite match the mighty TS-879U-RP, with its Intel Core i3 CPU and eight drive bays, but few NAS products can.
The 1 GB RAID 5 disk write test shows more clearly the strain that this particular RAID configuration puts on the NAS infrastructure. It's well known that RAID 5 write performance can be a weak point, with all the computation overhead involved and the extra parity bits that need to be calculated and written to each of the drives. The only way to overcome that is with raw computational horsepower, which is why the ARM-based models lag behind both the Intel Atom and Core i3 units. The simplest assignment any NAS can perform is basic backup duty, and in order to do that task well, you need to buy the most powerful system to effectively reap the benefits of a multi-disk array. That doesn't mean you can't do backups with a more modest unit, you just have to be smart about it. Don't have every workstation on the network set for an automated backup at the same time, for instance.
Next up is 10 GB (1000 metric megabytes / 10,000,000,000 bytes) file transfer testing. Using the 4-disk RAID 5 configuration in each NAS, and a single Gigabit connection, network throughput will be put to the test, and the effect of any system or hardware caches will be minimized.
10GB RAID 5 Test Results
Looking at read tests with a single 10GB file, the ReadyNAS NV+ v2 still hangs in there, with a read speed that's only 15% off from the highest performing unit. The results still favor the more expensive models, even though it's not a 1:1 ratio of improvement with higher cost. In order to do substantially better than this, you have to upgrade the network connection; GbE is only good for 125 MB/s, on a theoretical basis.
Looking at write tests with a single 10GB file, the results are not all that different from the 1 GB tests. The NETGEAR ReadyNAS NV+ v2 runs at almost exactly the same read speed - 42.3 MB/s v. 42.4 MB/s. The QNAP TS-659 Pro II is the only one that takes a hit with the larger file size, with a ~10 MB/s loss. If you're writing large files to a NAS, you can't afford to scrimp on system hardware; you need the biggest, baddest CPU you can afford. The various caches built into the host and target system help out on the smaller file transfers, but they get filled up and lose their effectiveness when dealing with large files like this. Once again, the TS-879U-RP just laughs at the additional load of four additional hard drives; the CPU utilization never got above 25% during this test. I had no way of gauging the CPU or memory load of the ReadyNAS NV+ v2, as the Dashboard tool does not have a monitoring capability that goes down to that level of detail.
All in all, my impression of these test results is that the ReadyNAS NV+ v2 is a good performer that should meet the market needs for its intended users. For home use or for a small business, it's a small, simple, rugged device that doesn't require a lot of knowledge to set up and use effectively. Nowhere was this clearer than when migrating from a single-disk configuration to a full 4-disk RAID 5 arrangement. The proprietary X-RAID2 software made it simple and easy; there was literally nothing to figure out - just add drives and wait. As a reviewer, I appreciate all manner of bells and whistles, especially if it makes it possible to measure sub-system performance. As a NAS user, I just want the thing to work reliably 24/7 for at least 5 years, be easy to set up, and have just enough features in the software to make it useful. The last part is different for everyone - there is no one size fits all.
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