Customer Reviews

D-Link DNS-321 2-Bay Network Attached Storage

5 star:		(36)
4 star:		(33)
3 star:		(14)
2 star:		(12)
1 star:		(13)

 

 

I've been pleased with the reliability and performance of the DNS-321. I was hoping the Gigabit transfer speeds would be significantly faster, but it seems to top out at 14-16 MBps (MegaBytes per sec). This is on the upper end of most consumer NAS boxes, including D-Link's tried & true DNS-323.

Pros:
. Runs cool & quiet.
. Spins down the HD when idle to conserve power.
. Rock-solid operation (no reboots necessary in the month I've had it).

Cons:
. Larger drives (1TB and up) can get "stuck" at 94% during the format phase, but eventually it will complete.
. User permissions setup is clunky. This is common among consumer-level NAS boxes though.
. User access permissions are cleared on reboot :(
. No firmware update yet (v1.0). D-Link tech support says they've fixed most of the problems above and are testing the new firmware for public release. The cons are relatively minor to me, and once fixed in firmware, this will be a 5-star product.

Notes:
Opt for a low-power (and low-heat) HD to use in an external enclosure. Transfer rates on this generation of NAS will never approach the max throughput of HDs, so using a fast 7200rpm drive is a waste of money and power. Extra heat from the faster drives may cause issues down the road. Recommended low-power models are the Western Digital GreenPower and Samsung EcoGreen.

UPDATE 11/30/2008: D-Link has released firmware 1.01 which fixes the issue with access permissions being cleared on reboot. It also claims to support 1.5 TB hard drives.
[...]

UPDATE 5/8/2009: User account access control has an issue in all firmware versions, from the original 1.0 release to the latest beta. Basically the setting to allow All users to access a share disappears. Resetting to defaults sometimes brings it back, but shares configured to allow All users don't work properly. Weird issues with the All checkbox and shares disappearing are very frustrating. Dlink tech support has been aware of this for 4-6 months but no fix is in sight.

Final Update: D-Link finally fixed the issue with All Users permissions in firmware 1.03. There are some lingering issues, some minor and some not so minor, but D-Link hasn't released a firmware in well over a year. Looks like D-Link has written off this product.

Well, it was working fine for the features I was using. Immediately updated to their latest firmware release. Put 2 1TB drives in it, all the backup options (rebuild drive, etc.) seemed fine as I played around with swapping drives out. Then I tried to copy all of my current data over to this NAS box. After about a full day of copying (I have several hundred gigs of files) I went to check the status of the backup.

The backup had completed... HOWEVER, since I had turned on data validation (rereads the destination and source files and compares after the backup) it noted that out of the 1000s of files I had backed up that 12 of them were "not equivalent to the source files".

I took down the names of the files and then did a hex dump compare of the old and new files. To my surprise the files that were copied onto the NAS box had *exactly* 76 bytes of zero in very specific relative offsets in each file. It was always at hex offsets with the last 3 nibbles of the file offset being in the range of xfb4-xfff that were all zero, in all of the "corrupted" files.

Puzzled, I did some Google searching and found that there was a Linux kernel bug found at the end of 2006 that just happens to exactly match this behavior! The kernel was losing the "dirty bits" (modified memory page indicators) when it was writing to ext2 or ext3 file systems (this box uses ext2). This only happened on certain "chunks" (76 bytes for the Linux case) if they were the 76 bytes that fall at the end of a 4k memory page boundary (the last 76 bytes of a 4k page are... you guessed it!! bytes xfb4-xfff).

The data I was transferring was from a Windows XP machine and this NAS box is internally running.. yep, LINUX! I believe they likely have a version of kernel running on this thing that was silently corrupting my data, as all the issues seem to exactly match my conditions.

That is the WORST kind of data corruption ("silent") because there were NO error indications at ALL except for when it had done the final recompare, which good thing I had turned that on or I would have NEVER known my data was being corrupted as it was copied to this NAS box!

I notified the D-Link tech support people about this issue, and they responded back saying that they are looking into what is causing the problem (think I gave them a good enough head's up on this one!)

I promptly returned the box to get my money back and am now running w/ a RAID 1 configuration in my main PC instead of having an external NAS box.

Support notes - I stayed on the phone for the D-Link tech support number for a good 20+ minutes, all I got was the answering service kept repeating "due to a large volume of calls, ... " so I just hung up and emailed them instead. Took them about a week to get back to me (but they did).

Other gripes about the box - the little levers to remove the drives were REALLY hard to use, my thumb got sore after swapping the drives a couple times for doing the failed drive testing.

This review is specifically about the DNS-321 as that was the only one I tested, however the DNS-323 is VERY similar to this box (just basically added a print server), so I can't say if that one is any better or does the same corruption as this one does (it's quite possible).

I bought this to test as an inexpensive file server in a small business, so I cannot comment about the UPnP server, FTP server, etc.

The unit ships with firmware v1.00, but that firmware has problems (RAID, large drive, fan settings, etc.) that are well documented, but firmware v1.01 was released in October 2008, and was supposed to fix those issues.

I immediately updated the firmware to v1.01 and began to test the RAID for reliability, etc. It turns out that v1.01 broke some important items for me - most notibly the permissions. As soon as you create a single user, the ability to select "All accounts" disappears. Further, every time you reboot the unit, you will lose all of the permissions that you set up. This is a bug, and D-Link is well aware of it since early November 2008 - you can read about it on their forums. It is now early March 2009, and they have not released an updated firmware.

I have it turned off and sitting on the shelf waiting for a new version of the firmware. If they fix it, this could turn out to be a nice unit, but until then, stay away if you want a reliable file server with RAID for a small business.

The D-Link DNS-321 is among the least expensive dual-disk RAID NAS systems currently on the market. This small device offers an impressive array of features such as FTP, Samba, NFS, iTunes, DHCP, HTTP and UPnP servers, user and group access management, several RAID levels, a well-designed Web interface and gigabit network support. It is this last feature that I would like to discuss in some depth.

Those of you who are not computer experts need to understand this: the DNS-321 is not just a small black box with two hard drives but an actual computer that has it's own CPU, memory and operating system. If, looking at the DNS-321's small size and low price, you were to imagine that it is not a very powerful computer, you would be absolutely correct. And there lies this gadget's only major flaw.

When originally designed, DNS-321's predecessor was intended for wireless or 100Mbps networks. The device's CPU and other system resources were precisely scaled to cope with 100Mbps (12.5 Megabytes per second) data transfer rate. This was necessary to provide the desired performance and features, while keeping the device as affordable as possible.

As time went on and gigabit (125 Megabytes per second) networks became more common in small offices and homes, D-Link's marketing folks must have felt an unbearable urge to include gigabit support in their low-end NAS products. The hardware was upgraded to include a new integrated gigabit network interface.

If you connect the DNS-321 to a gigabit network, true to the claim on it's packaging, the gadget will establish a gigabit link to your network. Unfortunately, painting racing stripes on your old rusty Ford Tempo does not turn it into a supercar. Running FTP, NFS, Samba, UPnP and other services supported by DNS-321 requires processing power and a certain amount of memory. These requirements grow with the rate of data transfer.

Unfortunately, DNS-321 has just enough resources to comfortably handle up to about 14.5 MB/s, which is a long way from the maximum transfer rate of a gigabit network. Thus, D-Link DNS-321 is a NAS system capable of establishing a gigabit network connection but not capable of using it. What do they say about having your cake and eating it? Not for a hundred bucks, my friends.

If you already own the DNS-321 and would like to get the most performance out of it, there are a couple of things you can do. First, you will need to upgrade the firmware to the latest version. Most DNS-321 units shipped without NFS server functionality, which has been added in the later firmware version. The upgrade is performed via the Web interface and the entire process was quick and painless. Turn off services you are not going to use, such as DHCP and UPnP, for example. Doing so will free up some valuable system resources and will slightly boost data transfer speed. Avoid using Samba - it is a resource hog. You will get at least 20% faster transfer rate using FTP or NFS instead of Samba. Unfortunately, there is no way to disable the Samba server. The speed offered by the DNS-321 is entirely adequate for playing uncompressed videos in 1080p resolution with a DTS 5.1 audio track. I've been streaming a 40GB MKV file via NFS to an XBMC player without any issues. However, as a file backup solution the DNS-321 is just too slow for my liking.

I've set up perhaps 10 different NAS boxes/servers over the last few years, I have 3 attached to my network currently - this Dlink DNS321 and two LaCie drives. This is by far my favorite for several reasons. For the price, its great that you get an expandable NAS box that supports RAID and any size drives you want to put in there. Its remarkably easy to install the drives, so even if you have no experience installing hard drives into a computer don't worry, its impossible to mess it up as they just slide in - buy OEM drives as you don't need the cables/screws that come in retail boxes. The other big reason I prefer this device over the other NAS drives I have and have had in the past is the speed. By consumer NAS drive standards, its a speed demon. I get roughly 6MBps as a solid connection over my wireless n network with 7.5MBps peaks and 14MBps over my gig LAN connection which are both about 50% faster than either of the LaCie drives that I also have currently connected.

Couple of pieces of advice if you buy this device. If you are only installing 1 drive at first, put it into the right bay as it will make things easier down the road (why? http://support.dlink.com/faq/view.asp?prod_id=2531&question=dns%2D321). Secondly, if you use Mac's, be aware that although these drives work very well with Mac's of course, the software Dlink gives you on the CD is Windows XP/Vista only. Although installing the device is very easy, setting it up isn't what I'd call straight forward so it helps if you've set NAS devices up before. The advice Dlink has on their website for Mac users connecting to the device is for the last version of OS X. But in a nutshell, in Finder, click on 'Go', then 'Connect to Server' and enter 'smb://" and after the // enter the IP address your router has assigned the device. Unlike other NAS devices, this one requires network know-how in that you'll need to setup User/Group permissions whereas some NAS devices give you a pretty GUI which hides this a little, but once you've set it up its a great little network drive. Once I need a couple more TB's, I'll be getting another one.

If you are looking to add storage without the hassle of internal drives then this is a great device.

The setup is easy and there are plenty of configuration options via an easy web GUI. It uses the EXT2/linux file system so fragmentation is not a problem.

I have two 1 TB drives set in a raid 0 for testing purposes and this thing screams on a gigabit network.

It is a very small and quiet and looks sleek.

Overall this is the best home/small business diskless NAS system out there.

This is a great product, very fast, easy to set up, and provides a straight forward control panel.

The documentation needs to be improved because nowhere does it say that users of the LAN are differentiated from FTP users, thus creating a problem with file permissions. For example, if you FTP into the drive, upload files, then come home and try to write/change those files/folders, YOU CAN'T!

You get a "file permission" error message when you try to modify those files using the DNS-321 unit.

All the files have the attribute "read-only" and if you try to change that from Windows (inside your LAN), you can't. The files revert back to "read-only" and without the "Archive" attribute enabled.

In the process of finding a solution to this "read-only" problem, I give their tech support a FAIL grade. Read on if you are interested in why.

There is a user's review on here that talks about certain files becoming "read-only". In trying to solve this problem, I called DLINK's tech support, and following this experience, I give them an FAIL grade.

I spoke to two people, the first one was Charles and he assigned me case number ALR400823065 (in case DLINK sees this and cares). After about 8 minutes of info taking (my phone in case we disconnect, name, address, serial number, etc.), we spoke about my issue for about 3 minutes, and Charles decided that I needed to speak with a "senior level" technician. Charles had a very slight accent, but did well in communications. The second technician (Tech 2) however, had a significant accent, so I didn't understand his name.

Tech 2, had me reboot the unit (which I had done with Charles). When I asked what does rebooting the unit have to do with file permissions, Tech 2 replied with a "we will reboot the unit now, sir". I asked again, and he wouldn't answer my question. I asked a third time what does rebooting have to do with file permissions, he raised his voice and said "just reboot the unit sir!". Surprised, I used a more serious tone with him and told him I asked a question and he did not answer. He explained something about creating a "base" for working with me, which okay, I understand. Well, at least that's what I thought he said, because of the thick accent, so okay. He then had me put the CD in my computer drive, and this is where it got weird.

He was asking me to click on things that didn't exist. For example, he said, click on "browse" on the menu. There was no Browse option. So I told him there is an option called "Easy Search Utility". Tech 2 was audibly exasperated, and raised his voice saying "okay, okay, click on that, sir". I did, the utility opened, and I informed him. He said "click to find drive". I asked, click on Configuration? He said "yes" loudly (lol). So I did, and that took me back to the web control panel where I had been trying to trouble-shoot the issue before the call. He said "sir, click on search", I said there was nothing with "search" on the utility. At this point I started to suspect Tech 2 has never seen this product's software. I said again, there is no search, what would you like me to do. He raised his voice a third time (which okay, I am starting to get annoyed), and said "sir, now you see files". I replied, sir, I simply opened the utility you asked me to open, I see no Search button. What do you want me to do. He raised his voice again, and said I "should see files". At this point I am offended by this behavior, so I raised my voice. I said: Okay, what is the action you want me to do? Tell me a verb, an action. I do not see the option you want me to click (search). You had me open three things so far and none of them have the option you want me to click.

He asked "what are the options in the Easy Search Utility?", I read them out loud. He mumbled something and then *click*... dial tone.

They didn't call me back. Isn't that why they spent like 8 minutes trying to get my information? So they would call me back if we get disconnected?

FAIL. They get a FAIL in my book for not knowing their product, for raising their voice to customers, and for not calling back to follow up on a case.

Summary:
I like the unit. Following that call, I went back to some basic things. I asked myself, if I am an FTP user, could it be that I inadvertently assigned attributes/permissions to the files and folders as that user? Could it be that because of those file permissions I cannot write on those folders/change those files? Well, I FTPd back into the folders, and sure enough... The files had permission issues.

For those of you who don't know, if you create a user, say user1, then user1 FTPs into the drive and creates files, writes some files, this user1 will be using a new userID (502). The default user number is 501 for LAN users (users that are in your home network and write/change files INSIDE your network on the DNS-321). The permissions were different for all files from user 502 (user1) and user 501 (the LAN users) cannot do a darn thing to files created by user 502.

So the way to fix your read-only file issue is to FTP using your user1 account, and change the permissions to chmod 777 (read/write for everyone). You can use FileZilla for that; just right click on the file/folder you want to change, and assign the 777 permission).

THIS SHOULD HAVE BEEN IN THE MANUAL!

I did a search on the manual and didn't find this little "trick", or info on this issue.

Have you come across this issue?

The DNS321 works excellent. Very easy to install drives, easy to set-up, and connected immediately. I wish the mapping tool was installed. I just moved it over from the CD to my local drive. I installed 2 Seagate ES2 500GB and am running RAID1 (mirrored). I used a laptop, and remapped all of 'My Documents' to the network drive. My only complaint is not about the product itself...it's about the speed via wireless. Lack of network performance is not very noticeable when only using the internet, butt when you're transferring large amounts of data, it's much more apparent. I have a DLink N router, and just bought a DLink N card. With the G card I was getting about 1.2 MB/sec, and with the N card I'm getting almost double. It's still slow compared to the wire, which was about 14 MB/sec (still not great). The performance was more of an issue when I was doing the initial transfer of all my files. Now it isn't really a big deal. If I need to transfer a lot of data, I just plug in.

I researched a lot of NAS units, and I deceided that I wanted to select my own hard drives. Most of the units which come with drives, come with cheaper drives. I went with 'commercial' drives which are built to be spinning 24/7. There is, however, a setting in the config firmware site where you can turn off the drives after a certain period of time...similar to your computer. Also, you can set it up to email you when a drive fails. I hope I never receive that email, but it's nice to know that you will be notified immediately. Haven't set up the FTP yet. It did pick up the NAS in iTunes, although I haven't played with it yet.

Anyway, so far, so good. Oh, and be sure you get SATA drives with the newest power connector.

I have THREE of these things. Obviously, I liked them at first. After a total of a month of ownership, two separate devices have killed 2 separate hard drives from different manufacturers. If you care at all about your data, DO NOT BUY THIS.

The Good:
- Good Price
- Nice Looks
- Easy Setup
- Possibility of installing additional modules to the unit

The Bad:
- The big one, the only one that matters - I've lost two hard drives in two weeks to these devices. Hard drives are brand new. Different capacities, different manufacturers. The actual circuit boards seem to be fried - in 20 years and 70+ hard drives, I've seen a LOT of hard drives die, but I've never had the circuit boards fail, always the mechanics. Now I've had 2 in these stupid NAS solutions die that way. They're new, from different manufacturers - the drive is unlikely the culprit. The enclosures are hooked up to a high quality surge protector, which is attached to a high quality battery backup and noise filter - the power supply is unlikely the culprit. Each drive was in a different 321 - it's unlikely that I have a faulty device. The ONLY explanation is that these things are really that lousy - I don't have a "bad one", this is simply the way they are. The first dead drive, I lost all my data. The second, I was smart enough to have mirrored everything (but still stupid enough to be using the 321).
- There's no visible warning on the device when a drive fails. You can set up the device to send you an email (which is cool) but really, you just don't expect things to fail that often, so I hadn't bothered setting it up. Why is this a big deal? Even if you try to mirror your data for safety, you won't know that there's a problem until both drives are dead. And at the rate these things kill hard drives, that might not be too long.
- In hindsight, this seems minor compared to the bigger issues listed above, but, back when I liked the DNS-321, one gripe was that, while they allow additional software to be installed on the unit, the available offerings from D-Link are slim and not very useful, and if you want to go with third party stuff you have to invest a lot of your own time hacking around and getting things to work.
- Another small gripe, looking back. There's no cushioning for the drives at all, a few rubber grommets would go a long way to reducing the noise.

The Other:
- If you already have one of these, or decide to get one anyway despite my warnings, PLEASE MIRROR YOUR DATA. It's worth the additional cost.

Conclusion:
- I know you'll be tempted to buy this anyway. But I'm telling you, the money saved is not worth the loss of your data, it's not worth the stress, it's not worth the hours you'll waste filling out RMAs, or the hair you'll lose praying you can recover something from a dead drive. Please don't make the mistake I did, buy something that's better quality. If you get this anyway, use RAID 1. And don't buy another for several months, give it a chance to ruin your day first.

I bought the DNS-321 to use as a Streaming Media Server for my PS3 along with a 1TB Western Digital Hard Drive to start.

I'm not a newcomer to computers or networking so I figured setting up a consumer NAS would be easy. Not so much with this baby. For Mac Users there is virtually no support from D-Link. The DNS-321 will run with a Mac but you are pretty much left on your own. D-Link instructions are terse and overly-brief without a lot of details or context. The "set-up" disk for the DNS-321 is Windows XP/Vista Only so, again, no help for Mac Users. The tidbits that are available on D-Link's website for mounting a Network Drive are three years and two OS Xs out of date. Support on D-Link's Forums is a fairly awful consumer experience that ranges from casual disregard to Uber-Nerd Rage by D-Link's own CSRs. And telephone support is a joke (thick Indian accents reading from scripts, no real technical proficiency) .

The upshot is I got the DNS-321 running after two hours but still haven't gotten it to stream a movie file to my PS3. And I'm still not sure I have the DNS-321 configured correctly to work with my Macbook. I'm not entirely sure whether I'll keep it or not, and I am a person that is loathe to return things.

The Product (i.e. Box) is fine. It's a NAS... But the set-up and support from D-Link is what makes it a three star product. If you are Windows User, or a Networking Professional your experience may vary, but I'd caution Mac Users to look elsewhere for a NAS device. Or prepare for a lot of long nights of Googling.

UPDATE: September 7th, 2009 -- No thanks to D-Link's Customer Support or Documentation I finally was able to stream movies from my DNS-321 to my PS3. Changed the file extension of my test video from .M4V to .MP4 So at least I can use this device for its intended purpose. However, I still maintain a three star review due to D-Link's poor Customer Service and totally lackluster documentation.