ReadyNAS NV Experience

The ReadyNAS NV comes with a proprietary implementation of RAID that Infrant calls X-RAID for expandable raid. As the name suggests, with X-RAID you can start the NAS with just a single drive and add additional disks at a later time to increase capacity.

• With 1 500 GB disk, the total space available is 500GB but there is no redundancy so if your disk fails all data is lost.
• With 2 500 GB disks, the total space available is still only 500GB, but the data is now mirrored so that one drive can fail without affecting operations.
• With 3 500 GB disks, the ReadyNAS switches to RAID 5 leaving you with 1000GB or 1TB of available space and the ability to tolerate one disk failure.
• With 4 500 GB disks, the ReadyNAS now gives 1.5 TB of disk space, again with one disk failure.

The ReadyNAS also has some additional features such as being able to function as a print server, host USB external drives, and stream media files directly to other devices without going through a computer.

Why I use it

I use the ReadyNAS primarily because its RAID capability provides security against drive failures. In my own experience, I’ve averaged about one hard drive failure every 2 years. So I expect my hard drives to fail and it is simply a matter of when. With a RAID system, I can lose a drive and still continue working normally.

My files also take up too much space to live on a single drive. With the ReadyNAS, the disk drives appear as one logical hard drive to the computers that connect to it and this is very convenient as I no longer have to worry about how I should divide up my data across several physical disks. Although the ReadyNAS internally splits the data across multiple drives, the details are hidden from the user. Before getting the ReadyNAS, I had many smaller drives (1 x 80GB, 2 x 160GB, 4 x 200GB, 400GB, 500GB, plus system drives and portable storage devices) and keeping track of everything and the backups was getting a little tiring.

Finally, the ReadyNAS provides network access for multiple computers. Since the ReadyNAS communicates with a network interface, I can connect to it from any computer in my house. In contrast, I could setup a dedicated computer to share the files but it wouldn’t be as easy or convenient and I would still also have the issue of providing redundancy in case a drive failed.

Setup

The setup was fairly painless. I just plugged the ReadyNAS into the ethernet port on my router and installed the RAIDar software that came on the CD. RAIDar is utility that searches for the IP address of the ReadyNAS since in most cases your router will dynamically assign it an IP address which may change over time.

To setup the ReadyNAS you can hit the “setup” button in RAIDar or directly type in the IP address into a web browser. Through the browser, you can configure access to the ReadyNAS by defining shares, which can be thought of as logical disks. For each share, one can set passwords and disk quotas if desired.

I have shares for my photography business, backup share for other computers in the house, media share for my music, and a share for temporary files.

In the browser, you can also configure the ReadyNAS to send email alerts. For example, if one of the hard drives goes bad and you need to replace it, the ReadyNAS can send you an email message letting you know about the problem.

The RAIDar software isn’t necessary to connect and use the device. Under Mac OS X, you can connect through the finder (although it often takes a little time for the finder to detect the ReadyNAS on the network) and under Windows, the ReadyNAS appears in My Network Places.

Speed

The ReadyNAS supports Gigabit ethernet and on such a network it is very fast although not quite up to the level of USB 2.0 or firewire. I can copy a D200 raw file (about 16MB) from the ReadyNAS to my computer in about 1.5 seconds. On my wireless network (54 Mbps), the same transfer takes about 12 seconds.

The table below shows a few examples of transfer times for the ReadyNAS and an external USB 2.0 drive.

Note that these times are computed using the ReadyNAS on default settings. There are a number of options that one can tweak to obtain better I/O performance.

Problems with the ReadyNAS

I had a few problems with the ReadyNAS that were easily resolved.

The first was a timestamp problem. I usually backup my disks to the ReadyNAS NV using a UNIX program called rsync. What rsync does is compare the timestamps for files at the source and destination locations and if the source file is more recent, rsync will copy the file to the destination drive. The problem I had was that the timestamps on the ReadyNAS files were sometimes off by 1 second. This caused rsync to re-copy the file even if nothing had changed.

I suspect this might be a rounding versus truncation problem. I haven’t yet figured out exactly the problem but the symptoms are easily avoidable in rsync by using the –modify-window option which lets one use fuzzy comparisons.

The second problem I had was that one of my computers (my main photoshop workstation) would not connect to the ReadyNAS at normal speed levels. In fact, the connection was so slow you would have to wait for directory listings. This really puzzled me, since all my other computers (both Windows and Mac) could connect to it fine. Eventually, I discovered the problem was the D-Link DWL-G520 PCI wireless card (that can supposedly connect at 108Mbps) and replaced it with an older version of the card that only tries to achieve 54 Mbps.

Direct Connection

It’s possible to directly connect your computer to the ReadyNAS. I usually do this when I want to transfer a lot of data to and from my Macbook Pro as it supports Gigabit ethernet whereas the rest of my network runs at 54Mbps.

To directly connect the ReadyNAS to the Macbook Pro:

• disconnect all cables
• set computer to use static IP 192.168.168.167 with a netmask of 255.255.255.0
• the ReadyNAS should appear at 192.168.168.168
• in the finder (Mac) use the go–>connect to server menu item with the IP address

Alternatives to the ReadyNAS (The Competition)

There are a lot of alternatives for photographers who want to store massive amounts of data:

• A single large hard disk. It’s now possible to get hard disks that can store 750 GB of data. If all your data will fit on such a disk, then it can be a good option. Simply purchase a large disk and use it as a working drive. Buy another disk, preferrably external, of the same size and use it as a backup.
• NAS systems that support up to 2 disk drives. There are several manufacturers that are producing inexpensive NAS systems that allow one to access 1 or 2 drives. However, invariably every such system I’ve looked at has serious drawbacks. For example, while the Netgear SC101 costs only about $100, it uses a proprietary file format, requires a special client to access the data, and users have reported overheating problems. Of course, with only two drives there is going to be no support for RAID 5.
• Other NAS RAID5 servers. There are several other manufacturers of RAID NAS systems such as Buffalo who makes the Terraserver and Anthology Solutions who makes the Yellow Machine. However, these have a number of drawbacks compared with the ReadyNAS. For example, it is difficult to replace drives on the Terraserver and the Yellow Machine does not support Gigabit ethernet. Furthermore, to my knowledge, the ReadyNAS is the only NAS box that supports incremental expansion with RAID.
• JBOD system. JBOD stands for Just A Bunch of Disks and the typical setup is a multi-drive bay that connects to a computer via firewire or usb. Prior to getting a ReadyNAS I relied on my 4-bay JBOD but it was a pain dealing with all of the individual disks. Furthermore, JBOD typically doesn’t support RAID so to gain redundancy I needed to mirror all of the disks
• PC with RAID card and several hard drives. This is a viable option and can be set up inexpensively if you already have computer that can be a server, but I prefered the convenience (and small size) of the ReadyNAS.
• Firewire RAID boxes. A firewire RAID box is a good alternative to the ReadyNAS. Firewire will be faster for a directly connected computer, but if you want to share the files over the network you still need a dedicated computer.

Conclusion

The ReadyNAS is a relatively inexpensive network drive that has RAID 5 capability. I found it to be well made and convenient to use. The X-RAID functionality means that it is easy expand as storage needs grow. The main drawbacks I see with the ReadyNAS are that it is a little loud for normal living spaces (there is no sleep mode) and file transfers can be slow unless you’re on a Gigabit network.

Additional Information

• Infrant’s home page
• Infrant’s discussion forum which also includes postings on equipment compatability issues.
• Review of the ReadyNAS NV by Tom’s Networking.

Tagged as: hard disks, memory, NAS, RAID, storage