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Synology

Synology 4 bay NAS DS420j (Diskless), 4-bay; 1GB DDR4

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Size: 4-bay; 1GB DDR4


Style: DS420j


Features

  • 4-bay home NAS with over 60 TB raw capacity support suitable for data backup and file sharing
  • 64-bit 4-core 1 4 GHz processor and 1 GB DDR4 memory
  • Over 112 MB/s encrypted sequential reading and writing throughput
  • Easy-to-deploy surveillance solution that supports up to 16 IP cameras
  • Energy-saving design with only 7 88 W consumed in hibernation mode

Standing screen display size: ‎75


Hard Drive: ‎Mechanical Hard Disk


Number of USB 2.0 Ports: ‎1


Number of USB 3.0 Ports: ‎2


Brand: ‎Synology


Series: ‎DiskStation


Item model number: ‎DS420j


Item Weight: ‎8.1 pounds


Product Dimensions: ‎9.06 x 6.61 x 7.24 inches


Item Dimensions LxWxH: ‎9.06 x 6.61 x 7.24 inches


Flash Memory Size: ‎128 GB


Hard Drive Interface: ‎Serial ATA


Batteries: ‎1 A batteries required.


Manufacturer: ‎Synology


Date First Available: ‎January 7, 2020


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If you place your order now, the estimated arrival date for this product is: Sunday, Jun 9

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Top Amazon Reviews

    • My first NAS. Good for a home of 2 or 3 light users. Uses Linux so be prepared for that.
Size: 2-bay; 512MB DDR4 Style: DS220j
UPDATE 08 January 2023 Synology DS220j The DS220j is a 2 bay NAS. I use RAID-1 so basically it reads and writes to two drives simultaneously so each one is a copy of the other. I've discovered the drives can not be read in a Linux or Windows computer if you remove them from the unit. The data partition is not a mountable ext4 partition as it should be. It's not visible in linux nor in Windows with extensions for reading linux in Windows. There's a posted tech bulletin at Synology on how to recover RAID drives but I don't see how that will be of any use if computers can't even detect the partition. Once I clone a copy of both drives I can experiment with them. Maybe there's some magic in the knowledge base bulletin. Just google this exact phrase and you should be led to the algorithm for recovery: "How can I use a PC to recover data when my Synology NAS malfunctions?" Maybe installing mdadm and lvm2 as described in the bulletin will make the data partition visible. I hope so because I'd like to upgrade to a 4 bay unit but I don't feel comfortable about that until I can read the drives in a computer so I can recover from a NAS failure. UPDATE 04 January 2023 Not really an update but something I think will be helpful to many NAS owners...and I love to help. I'm slow in catching up with technology but I discovered a fun thing that can let us experiment in a very safe way to practice using a Windows computer to read the Linux file system files on the internal drives of the Synology DS220j NAS (it writes in Linux file systems to the internal drives...not in Windows file systems to the internal drives). But this practice technique requires one of those standalone drive cloning devices and it requires another hard drive that is the same size or larger than the Synology drive you copy. (You can get used...very used but usable...4TB retired server drives for about $35 on the auction site and those are good enough to play around with...just don't depend on them for precious data.) You just shut down the Synology, remove one of the drives, then clone it using a standalone cloning device while the cloning device is not connected to a computer. My little cloner can duplicate a 4TB 7200 rpm drive to a 4TB 7200 rpm drive in about 6 1/2 hours. So, you can shut down the Synology while you are gone for about 8 hours or while you sleep and then the cloner will make a copy and you just insert the original drive back into the Synology and fire up the Synology again. The original drive you temporarily removed from the Synology is not altered by the cloner in any way so it's a safe way to make a copy and the Synology won't know it was ever tampered with. With the copy you made, you can then experiment getting files off of the Linux drive using Linux, Windows, or Mac and be prepared for some day in the future in case your Synology fails catastrophically forcing you to connect your Synology (Linux) drive to a computer to get files off of it. If you develop a plan and practice it beforehand...there won't be a need to panic...you'll be ready to do the deed and get on with life. There's a whole bunch of those cloners even on Amazon for as little as $30 up to maybe $110. As best I can tell...they all pretty much use the same JMicron JMS551 chip if they are the USB 3.0 gen 1 (5Gb/sec) cloners but most of the USB 3.1 gen 2 (10Gb/sec) cloners use the ASMedia ASM1352 chip . Those chip differences only affect the cloner dock if you use the cloner dock as simply a dock to connect to a computer. The cloning function is done with the little cloner device totally disconnected from a computer. So, as far as I know...and I could be wrong...check me on this...the speed at which those cloners can duplicate a drive are all pretty much the same. The duplication speed limit is based on how fast the drives can read and write data. Like a 5400 rpm drive might max out at 180 Mb/sec data transfer speed where a 7200 rpm drive might max out at 250 Mb/sec or so. (So...to calculate the time required for duplication...let's say we have a 4TB drive (same as 4,000,000 MB) ... 4,000,000 (MB) ÷ 180 (mb/sec) ÷ 60 seconds in a minute ÷ 60 minutes in an hour is 4,000,000÷180÷60÷60= 6.17 hours estimated time to clone a 4TB drive to a 4TB (or larger) drive. (The drive to which you copy has to have at least as much space as the one you copy from.) I have been afraid to pluck a drive from the NAS to practice reading it in Windows because every time I connect something to a Windows computer, it gets the mysterious $Recycle bin directory and the mysterious System Volume Information directory. I'm assuming Mac's might spew files onto a drive as well...I don't know...Mac is Linux...in a way...but not exactly from what I hear. Well, it worries me that if I then put that drive back into the Synology after it was connected to my Windows computer where I have the Synology set up with two drives in RAID-1 configuration, there's going to be only one of the drives that has those Windows System Information and $Recycle.bin files. Would this not lead the Synology to recognize something is different? Wouldn't that lead to corruption some day? After all, Linux in the Synology doesn't put those directories there...only Windows does that...so one of the drives in the Synology will now have those mysterious Windows files but the drive that has never seen a Windows computer will not have those mysterious files.....but...Linux can still see them and detect them...can't it? I dunno. I've just been afraid to do it. So, I cloned it and practice on the clone. That's safe. So...once we have a safe copy of our Linux based files as they are written in Linux also on our copy...we can practice connecting that copy to a Windows computer. You'll have to google for your favorite method of reading Linux file systems using Windows or using Mac--but there are tons of tutorials in video and text all over the web. Good luck. I gotta tell ya I'm liking this Synology box more and more as I learn to command it to work for me. In the beginning...it had me jumping through flaming hoops for no reason. Now, instead of jumping through hoops, I'm sitting at my desk getting work done and the Synology is working for me...not me working for it. And...if some catastrophe occurs...I'm ready with some practiced methods to recover from my Linux drives from the Synology as best can be done. UPDATE 22 September 2022 My Synology DS220j has been up and running about 2 years. It seems okay for the price. The two 5400rpm drives are adequate to saturate the full capacity of my gigabit network for one user at a time. I could be wrong but I calculate my network maximum transfer speed as 1,000,000 bits (gigabit) per second ÷ 8 bits per byte = 125,000 bytes = 125 megabytes (MB) per second and that' pretty much what I get when transferring to or from my Synology DS220j using computers in the house using copper wiring. I get a little less when using my 802.11ac WiFi. The Synology operating system is named Disk Management System...DSM for short. It's a nuisance in many ways. It forces upon the user a whole bunch of snooping, indexing, and reporting packages that do nothing for me but wear out my Synology NAS. Underlying that problem is the fact that I don't like the idea of people snooping even if they try and convince me they are honorable and do it only anonymously. I am skeptical of those claims because, after all, there are tons and tons of updates constantly to fix unforeseen thousands of problems and if there are that many errors, it means that any so-called seurity in the sytem that keeps things anonymous is likely to be flawed also. Synology is not entirely forthcoming with solutions to shut down this stuff. So, I found a 3rd party site to which I subscribe that is tailored to people like me who want to regain control of their data security in this Linux box called a Synology Network Attached Storage (NAS). That site breaks the solutions down into algorithms even I can follow. It is interesting to note that the Linux coders of the site can also describe how people hack your NAS from outside your network to pretend they are Synology. That means your anonymous data isn't always anonymous and your data isn't always deciphered by honorable people in the forefront. A "package" is what Linux calls its application installers. The fixes revolve around root access to the Linux operating system of the Synology using console commands to uninstall offending "packages" and then going a little further you can shut down particular access portals of internet access breach. It works and it's pretty easy. I use Linux Ubuntu on a couple of home computers so the Linux OS is not totally foreign to me. Probelm is, when you work to get everything removed that you want removed and batten down all breeched portals, you have to do it all over again if you allow another DSM update to occur. Every DSM update brings back the same stuff you worked to get rid of and there's even more new snoopers to discover and disable. It's a hassle. So, I looked at my situation from a practical standpoint and realized there's no valid reason for me to give internet access to my NAS because I only use it at home. If I pulled data from home to use elsewhere, I'd have to manage a good VPN with some very good end-to-end encryption on every device involved so my needs here in my little home cannot justify all those additional layers of complexity in my little life. So, I now use my router to totally exclude my NAS from internet access and I have never missed out on a thing while my life is much simpler and easier to control. I removed all of the bloat snoop packages and my DS220j works faster and smoother than ever before. Before removing the bloated snoopers, I had troubles accessing encypted archives on the NAS. Once the snoopers were gone, I have no more problems with encrypted archive containers that I access across the network when they are remotely stored on the NAS. It's a wonderful thing to no longer have to suffer the anxiety while I cringe thinking that access errors reported by the operating system might mean an entire "container" of encrypted data might be corrupt and unusable. I don't know what the snoopers were doing but it certainly jumbled some critical data streams in some way. That doesn't happen any more now that the bloated snoopers are gone and internet access is thwarted. I made sure I had all of the "packages" needed before I exiled my NAS to a secured utopia of peace and protection. The built-in package manager of the NAS won't work without internet access but there are other ways of using Linux commands to manage packages and examine that which is there. But, actually, I don't need to manage packages. All I need is there and it works. No need to fix what isn't broken--as they say. So, now my little NAS is secure and sheltered and happy. It serves me well. I don't seem to need any updates to improve functionality beause speed-wise it already saturates my little network so it's not as if I need for it to go any faster. I haven't discovered any data losses or data corruption so I don't seem to need DSM updates to improve data integrity. I keep my NAS backed up to another hard drive in a very high end USB enclosure so that gives me a back up for my backup. So, my NAS seems to work without problems and I have a backup for the backup if the NAS totally fails...and...like all things human made...it will fail...someday. It's basic but it works. The drives in the Synology NAS are using Linux ext4 file systems. If you need to use a Windows computer, Microsoft Windows can read and write those est4 sile system drives (btfs file system reportedly has Windows drivers but I have not tried them) if you install some freeware drivers so...theoretically....if the Synology NAS makes magic smoke, I might be able to read and access and copy data from the enclosed drives if they weren't totaly corrupted by the offending smoke generating failed hardware. And, if all of that fails, then the attached USB hard drive has one mirror that is made daily so all is not lost. And, then, about once a month, I copy the entire NAS data to an encrypted drive while that drive is attached to one of my computers. (I only have about 1.5TB of data on my 4TB NAS.) Somewhere in that mess I should be covered against total loss. (You make an encrypted copy so you can store that encrypted drive away from your house in case of fire, theft, act of God, etc.} Whew! What a job, huh? ORIGINAL REVIEW If you need speed, be sure to spend the extra to get 7500rpm drives (like Red Pro). I got the 5400rpm models (Red plain) and that leaves me lacking some transfer speed when I have the Synology mirror itself to an attached USB SATA. 5400rpm internal drives in a dual drive RAID is fine for my reading/writing to the NAS but when trying to copy from the NAS to an attached USB, it is sluggish. I wanted to make full backups of my NAS daily. I can't. It would take 12 hours or more to copy 3 TB to an attached USB and there is no 12 hour contigous period in a day when I can let the NAS lay dormant to do a full copy to an attached USB. So, I have to mirror to an attached USB instead. The USB copy utility is not entirely reliable in mirror functions. It will fail to backup some files. I have also learned not to set the NAS to hibernate the drives because it failed to write a whole lot of document scans. I mean gigabytes worth I had to redo over many hours because the writes to the internal NAS drives for some reason unknown to me totally failed for a large part of data and lots of files just were not there the next day when I resumed a scan and archive task. So, I turned off drive hibernation for the NAS drives and have not encountered that particular data loss since. You would think that the Realtek chip would hold data in the RAM until the drives spun up but I guess if there's not enough RAM, it just drops the data unless the hard drives are ready to suck it in. I don't know. All I know to say is think twice before using the hibernate function for the internal drives. Hard drives made for NAS are supposed to be built to run 24/7/366 so that's what I do now. Tech Support was disappointing. I had two issues. They just gave me links to Wikipedia pages and told me that Synology just doesn't give them access to the kinds of information they need to answer my questions. I told them thanks but no thanks because I can probably google better than they can. I needed Synology technical help. I did not need an auxiliary google search. The Synology (like lots of these NAS things) don't have licenses for Windows so they use Linux. That's fine. But, if your NAS fails, you will probably need to pull a drive from the NAS and hook it to a Windows computer to get some stuff off of it. Don't wait until you are in a panic state to do that. Learn to do it before you need to do it. You can read Linux drives with a Windows computer. Windows 10 has a virtual Linux machine you can activate but it's not needed. I stuck to the standard EXT4 file system in the Synology so I can use some freeware add-ons in Windows to read from the Linux file system of the drive I pluck from the Synology. I'm not sure I would write to one of the plucked drives though. It may cause more problems than I would want to deal with. ... show more
Reviewed in the United States on November 14, 2020 by Rusty
    • Nice box with good remote backup utilities (Backup,Sync with Amazon S3 and BackBlaze B2)
Size: 2-bay; 1GB DDR4 Style: DS223j
My first impression after troubles with Terramaster F2-210 is very positive. I bought a diskless NAS, and two 8GB HGST used server drives. The mounts are on rubber vibration isolators, it came with all (and spare) screws, very neat case, easy installation. After startup, it downloaded the software from the internet, and got ready after intuitive user interface questions. The power consumption in operational standby is ~1.25A 12V - which gives approximately 15W. The spinup current is ~3.5A. I do not recommend spindown with server drives, the box should be constantly running. The fan and enclosure are designed for proper cooling. So mechanically the box is very decent. The setup of shares and applications was best compared to other NAS I had. Most importantly, it offers both cloud synchronization service to share files with others, and *cloud backup* service that allows to keep multiple versions of compressed backups on Amazon S3, Backblaze B2 and others - the important features not available on few other NAS boxes. It can do compressed storage volumes for backup, and faster folders for local sharing with SMB protocol. At first glance, this is a happy buy. I will update the review after 6 months. Update: the user needs to know basic Linux shell scripting to get advanced functionality. Took me some time to arrange periodic synchronization of my other network drives to a backup copy on NAS. A bit of effort, but result is rewarding (using rsync). ... show more
Reviewed in the United States on October 6, 2023 by Dim
    • Nice Little Mini-NAS, Tech-Savvy Users Only
Size: 2-bay; 512MB DDR4 Style: DS220j
So this is a low-end, "consumer-level" NAS from a company that mainly makes far more expensive systems for large commercial users. That is both a strength and a weakness of this product. They have made some efforts to streamline the install, but they really haven't completely reworked everything to make it completely idiot-proof or easily accessible for people with limited IT skills. Instead, they basically give you most of the same administrative tools an IT pro would need and cut you loose. There is a web interface and it is not crazy complicated, given that a NAS is basically just a hard drive that is connected to your network, but the initial learning curve is a bit steep, even for somebody who is reasonably tech savvy. You start by taking the thing apart so you can install the hard drives yourself, using a screw driver. You then want to set up a static address for the thing on your network, which means going into your router settings. For all but the most basic needs, you will likely also need to forward some ports. If any of that sounds scary, then just stop right now, this product is not for you. Just pay somebody like Google Drive or Drop Box to store your stuff in the cloud for you and forget about a home NAS. But if that doesn't terrify you, what you eventually get is something that is really pretty useful for storing and accessing your documents, photos, videos etc. You can log into the NAS remotely through their secure portal and download stuff from your home network or push stuff up to it. And it can even stream your media to your phone, tablet, Roku box etc. as long as the media involved is fairly undemanding. This thing doesn't have the horsepower to handle like 4k video streaming, but it will generally stream 1080p MP4 just fine using its own, somewhat limited, proprietary media server. If you are doing high-end video editing or whatever this isn't the NAS for you obviously, but for people with more basic needs, it should be fine. If you are reasonably tech-savvy, all of this stuff is ultimately not wildly complicated, but they definitely don't hold your hand at all, either. You will inevitably be doing some swearing and some searches on Google for "how do I..." Where this device truly comes into its own is that the administrative tools are incredibly extensive and there is a whole slew of surprisingly advanced stuff you can do with it. For example, do you want it to sync to another Synology NAS off-site so you will always have a current, off-site backup? No problem. In fact, there are probably at least a half a dozen ways to run local, remote or cloud based backups of the files on your NAS, and the configuration options are really astonishing. You can give different users their own private spaces, given them shared spaces and the like. So basically, everything you'd need to run a small or mid-sized office is still here in this consumer grade device. What don't I like? Most home users want this thing for a relatively simple and discrete set of tasks, and it is probably going to be sitting idle 23+ hrs a day. So most of the time you want the drive spun down and the thing not being a wasteful power vampire. You need to be careful what applications you install if you want it to idle, certain apps, most critically Plex, tend to keep the thing fully on and spun up all the time. So keep your install lean and stay away from the 3rd party apps like Plex if you want it to actually idle down when you aren't using it. I would rate the noise it makes as reasonable/modest. It probably could benefit from additional sound insulation if you want to put it in like a bedroom. There is at least a setting to turn off the blinking lights, but it is basically a small fan and some hard drives in a plastic box with a bunch of air holes that you can't cover up. That's not a recipe for dead silence. I didn't find it overly obnoxious, but I also decided I didn't want it in the same room as either my home office or my home theater. So I put it in a closet so I wouldn't need to hear it at all. If you have a lot of old, legacy video in like .avi format, expect to spend a fair bit of time with Handbrake, as the "DS Video" application they provide for streaming video through the NAS does not have anything like VLC-levels of support for legacy video codecs. I found that you really want everything you stream over this device in MP4. Nobody is going to be running a private Netflix with this little thing and its dinky memory/processor, but it would be nice not have to re-rip all your old home movies and such to a modern codec just to play them through your TV with their software. UPDATE: I still like this thing as a way to get some aspects of an enterprise-grade NAS in a very cheap package, but understand that it is for fairly undemanding use only. It generally handles a single, 1080p stream with ease, but if you have multiple people hitting it at once or are uploading and downloading a bunch of files to it at the same time, you will notice it bogging down a bit. My sense is that the processor and memory are scaled to the premise that only one or two people are going to be using it at a time, and so once you start to pile a bunch of concurrent tasks onto it, you will wish you had spent more money for a NAS with more powerful internals. So a big family or small office might want to consider spending a bit more and moving up to something more powerful than this. ... show more
Reviewed in the United States on February 7, 2021 by team W

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