Digital media is so common in today’s modern society. Even people who would not be considered “tech nerds” have many gigabytes of personal data. Be it MP3s, digital photos, eBooks, or documents, people accumulate a lot of stuff.
All of today’s digital media is usually strewn all around the house in a disorganized mess. This is one of the primary reasons to get a good NAS, which incorporates several web and media servers with online storage and automatic backup.
While a single NAS is an elegant solution, everyone’s media library grows, and the NAS has to expand with it. One can expand their NAS with external USB or eSATA drives, but these ideas come with some ugly caveats (which I’ve written about here).
Why upgrade instead of adding external drives?
Most NASs’ services are configured to only look on the first volume. For example, UPNP is no longer automatic on external drives, which can majorly impact the SAF (Spousal Acceptance Factor). Our family has several torrent subscriptions to our favorite shows, and they don’t show up from the Playstation or Xbox 360 unless we refresh the UPNP server on our Diskstation DS409. What good is an advanced media system if you lose the spit and polish that made it so attractive? This is one major reason to upgrade your primary array. External drives are still useful… but use them for backup.
The best way to expand your NAS and maintain its functional integrity is to upgrade the primary array. Our focus for today’s article is a Synology Diskstation 409 with four 500GB Western Digital WD500AAKS-00D2B0 Blue hard drives, which ran out of space a long time ago. In order to have space (with room to grow), I’m replacing these drives with four 2TB Seagate Barracuda XTs.
On the next page we go over what to look for in replacement drives…
Most NAS units do not need the fast data rates of today’s modern hard drives. Even the fastest units can’t even reach 60 megabytes per second, which even the slowest of hard drives is capable of doing. Even a slow high-capacity 1TB drive can deliver nearly 100 MB/s, so why not use “green” hard drives that have slower spindle speeds (and thus produce less heat)?
Because Synology says so, that’s why. I originally purchased some inexpensive energy-efficient Western Digital 1.5TB WD15EADS-00R6B0 drives for the upgrade, but they have huge red flags on Synology’s compatibility list (http://www.synology.com/enu/products/compatibility.php). These drives have a very high Load/Unload Cycle count, which can severely reduce its life in an NAS product, which is extraordinarially bad in a RAID configuration.
Seagate Barracuda XTs are quiet and reliable… just what an NAS needs
More expensive drives are either faster, or have a significantly lower data failure rate… the latter of which makes for a better RAID volume. If you have a bad drive in a RAID 5 configuration and another one has a data failure error during the rebuild, then you’re pretty screwed.
I finally settled on four Seagate ST3200641AS Barracuda XT 2TB drives. A single one of these desktop drives can easily produce transfer rates between 100 and 140 Megabytes per second, which at first glance is overkill for most NAS units. I selected these drives for their reliability, especially after reading how inexpensive “green” drives can be unreliable in a Synology NAS. It turns out that the Seagate drives also ran a few degrees cooler than the WD Blue drives they replaced.
On the next page we show you how to physically install your new HDDs. It’s not scary, we promise…
First thing to note: if you don’t have the latest firmware of your NAS, then upgrade to it. During my research I’ve found that people run into more issues when using older firmware.
Upgrading the primary array on a Synology Diskstation is pretty straightforward, but will take a rather long time. Some NAS units (like QNAP) have a data migration tool which walks you through the data migration process, one drive at a time. Synology does not have a tool like this, but the process is the same. You must replace one drive at a time, rebuild the array, then replace the second drive, and so on until all of the drives are replaced. The system them automatically expands the volume to use the unused space.
You’ll have to take apart the DS409 and have it sitting open for a while until the process is complete. Thankfully, you will have 100% uptime during the rebuild process (minus the shutdown time to physically switch drives), which would not be true if you were to build a new array from scratch.
The Synology DS409 does not have “hot swappable” bays, and instead requires that the system be shut down during each drive change. In a normal RAID system you can click a button to “remove” the drive from the array and then physically replace it, all while the system is online. This does not appear to be the case with Synology, so the safe way for the system to detect the new drive is to shut down and restart.
The Synology Diskstation DS409 comes apart rather easily. Just twist the four thumbscrews at the back of the unit, and the back flips down. You can then remove the top and sides of the unit, which reveals the semi-hot-swappable drive bays.
I say “semi” hot-swappable, because you must first remove two screws on either side of each drive before you can pull out its plastic tray. You must then remove screws from the bottom of the drive to unmount it, and then attach the new drives to the tray with the same screws. Then insert the tray back into the slot and turn the NAS back on.
The upgrade flowchart… too bad each step takes over 3 hours.
The NAS will behave a little differently when it is powered back on. The power button will flash and boot up will take a little longer, about 2 to 3 minutes. You will then hear a constant beep warning stating that the array is degraded. Once you start repairing then this beep will stop.
On the next page we rebuild the array with software.
Open up a web browser and log in to the DSM (DiskStation Manager). Then open up Storage Manager and click Volume 1. Click the now-active Manage button and you will be brought to a Wizard that allows you to Repair the array. Go through this wizard and the volume will start rebuilding.
Array is degraded after physically replacing a drive. Time to run a repair
The rebuild process is very slow, as it took over 3 hours per 2TB drive. One might think that it would be quicker to backup your data, rebuild a new array, and copy the data back over, but you’d be wrong. Initializing an array takes a long time, and some users have experienced over 24 hours just to initialize an 8TB array… and that’s BEFORE you start moving data.
Left: rebuilding the volume. Right: First new drive sucessfully upgraded
Repair Wizard: Select repair, then select the new larger drive, then let it run for 3 hours.
Rebuilding the array for each drive will take about 3 hours or so, but the last drive takes the longest.
Once you insert the last drive, you need to prepare for an extra-long waiting time. The system has to do two additional tasks on top of a normal volume rebuild. The system then checks parity across the entire array (all 8TB of it), which can take between 4 to 6 hours. Then the system will do an automatic expansion, which will take many more hours. Be sure do insert the last drive just before you go to bed and perhaps it will be done by noon the next day.
If for some reason the Diskstation did not expand, then you can manually do this in DSM. Go into Storage Manager, click Volume 1 and then click the Manage button. There is an option to expand the volume with unused space.
Now that your array is rebuilt, you want to start copying. On the next page we have some tips that will save you some headaches…
After you have your new array, then it’s time to fill it up! Take out all of those spare hard drives, Blu ray discs, DVDs and start copying like a madman!. You probably want to remove any symbolic links that you may have set up (if you read my last article on the subject).
You may think that physically attaching a drive and then copying them to the volume via a command prompt or File Browser utility would be quicker, but that greatly depends on the file system of the source drive.
Copying files from an external USB drive like this might seem faster than the network… but you could be wrong
Although the version of Linux used by the DiskStation can read files from an NTFS drive, it is painfully slow to access (as in 1MB per second slow). It would be much quicker to copy them from your Windows PC to the DiskStation over the network. If your data is stored on FAT32 or EXT3/4, then the file copy process will be as fast as the drives can write (like 80MB/second or more). Note that FAT32 does not support files over 2GB, so those large MKVs cannot be transferred in this way.
The only real shortcut to rebuilding a RAID 5 array is using a more expensive RAID card or faster host processor (if using software RAID). Most NAS boxes do these parity calculations in software, which accounts for the performance difference between these appliances and a powerful server. You’ll just have to be patient and realize that upgrading and migrating your data will take up most of your weekend. The beauty of RAID 5 is that you have access to all of your media during the entire process.
I hope this article takes the scare out of upgrading your Synology Diskstation NAS. It can take a while, but the satisfaction of having instant access to everything is well worth it.
1 Comment
It looks like you've got some of the fastest, most expensive Seagate drives you can get… and you're putting them in a slow NAS? Those drives in a RAID 0 or RAID 5 confiig could easily do 400 MB/s (or faster), and your NAS probably only delivers 40-50MB per second.