

The Problem
Acme Inc needs file server migration support. File Servers come in all shapes and sizes. In this scenario, the file server is a Synology DS414 with 4 x 2TB disks in a RAID 5 configuration. Currently there is 4.4 TB used out of an available 5.7 TB. Acme Inc uses the Time (Hyper) backup applet to perform backups which gives the availability to restore different versions of a file. There are also some pretty good alternatives backup apps are Glacier and Idrive Backup.
NOTE: The backup destination in this example known as Cox Premier, AKA the home office is 150/10 megabits. The 10 megabits /8 = 1.25 megabytes per second * 60 = 75 megabytes per minute * 60 = 4.5 gigabytes per hour (drop 10 percent) 4 gigabytes per hour of backup data that can upload to the home location.
Additional HyperBackup Resources:
The Solution
We propose to implement a new Synology DS1515+ unit. The DS1515+ is a 5-bay unit and has the option to add an expansion unit to bring the total drive numbers to 15. The DS1515+ comes with double the RAM of the DS414 and is expandable to 6GB (from 2GB). The two network interfaces on the DS1515+ can be combined into a Link Aggregation Group (LAG) if you have the network hardware (switch) capable of handling a LAG.
Three Options
Note: Options 3 is the quickest but is also the riskiest if you are not confident in your snapshots or backup recovery options.
There are three different ways to implement file server migration support. The first thing that should be done is to back up the existing data to an external disk for safety. A 5TB USB3.0 drive will cost about $140, the initial backup will take 3 days but can be done while the system is online. ***Not necessary if you are confident the Hyper backups are working.
Option 1 – EXT4 underlying file system and limited increased space
Move Existing Disks
The simplest and fastest way to perform this implementation is to move the existing drives out of the DS414 into the DS1515+ and perform a Synology Migration. This will bring the unit up exactly the way the DS414 was configured (with Shard Folders, Users, Access controls and Time Backup) in about one hour.
NOTE: RAID 6 option would allow for two parity drives. This allows for the potential loss of two drives. We chose RAID 5 in this scenario.
Adding the New Disks to Existing RAID 5
An additional (2 TB) disk can then be added to the unit and the RAID 5 set can be expanded to include the new disk giving an effective disk space of 7.6 TB (so approximate utilization will be 58%).
Cost for this will be $(DS1515+) + $(2TB drive) + $(labor). The DS414 will then be extra but will have no drives in it. The RAID5 expansion should be performed over the weekend so as not to impact user performance.
Note: The latest NAS drive is 8 Gig
There are a couple of concerns with this method. The first is that the future of Time Backup is uncertain; Synology had stopped active development of it in favor of their new Hyper Backup. The second is that it will continue to use the EXT4 underlying file system which is a good file system but lacks some features of the new BTRFS filesystem (specifically snapshots which could replace the Time Backup functionality.)
Also, you didn’t really solve your problem of increasing disk space by much.
Option 2 – Copy DS414 to DS1515+
The second way of performing the implementation is to set up the DS1515+ with new drives, copy the data from the DS414 and then restore settings from the DS414 to the DS1515+ (so that Shared Folders, Users, etc. are transferred). Cost for this will be $(DS1515+) + $(drives) + $(labor). The DS414 will then be extra and will already have drives.
The biggest “problem” with this method is the time taken to perform the copy of data. It is difficult to estimate how much time it will take to perform the transfer because of variabilities introduced by the number and size of files. We can say that it will absolutely take a minimum of 13 hours and could easily take 36 hours. There is a way to mitigate this and that is to perform two sets of copies. The first copy will be an online copy copying all data potentially while users are still accessing the DS414. The second copy will be an update copy where all users are kept out of the system and only the changed data is copied. Depending on how long the copy takes, this could actually be completed over a weekend with the switchover to the new DS1515+ occurring first thing Monday morning, thereby minimizing downtime to the users.
There are some additional considerations; the drives will be all new and so that will add to the cost, and the “new” system would not be able to use Time Backup. To handle the versioning problem introduced by the loss of Time Backup we would implement the snapshots feature of BTRFS which will allow access to some but not necessarily all versions of a particular file. This is configurable and we can arrive at a schedule which meets your needs. If the DS414 is kept as-is (we would of course need to rename it) then you could continue to have access to the Time backup copies on the DS414. At some future time you could re-purpose the DS414 when you’re reasonably certain you no longer need access to the Time Backup copies. With new drives being installed in the DS1515+ you can choose which size drives you want to have; 2TB drives will give you 7.6TB usable space, 4 TB drives will give 15.2 TB usable space (although you could also choose to implement a second level of redundancy dropping that down to about 11 TB).
Option 3 (A lil risky but fastest)
Migrate legacy RAID 5 Disks -> Copy to 1 Independent Volume or Disk –> Copy shares back to upgraded RAID disks
There is a third option that I consider a little riskier but has the advantage of being able to be staged over time. That is to perform the migration option discussed as option 1 but NOT to add the 5th disk as a RAID expansion. The 5th disk would be a 6TB disk and would be configured as an independent SHR volume. The shares would then be moved over to the independent volume. Reformat the existing disks (or emplace new ones) as BTRFS instead of EXT4 and then move the shares back.
Note: Does configuration carry over with the data during this copy to independent disk?
This is riskier because for a while all of the data would exist on a single disk. If the users are accessing the data then it would be slower for them because they would be competing for a single spinning spindle. It is however possible that the whole thing could be done over a weekend without user impact – i.e. go in and do the initial migration to the DS1515+ last thing Friday, do the work necessary to move/format/move back the data remotely over the weekend. If this is done then it is imperative that the USB backup be made and updated before work starts.
Scenario 2 – DS215 Migration to DS1515+ File Server Migration Support
3TB are being used in the legacy system. Migrating to a new Synology NAS 5 bay chassis and adding 3 (8 TB) disks in a new system will provide 16TB of effective disk space. Cost for this will be $(DS1515+) + $(8TB drives) + $(labor). The RAID5 expansion should be performed over the weekend so as not to impact user performance.
Move Existing Mirror (4th and 5th Disks)
The simplest and fastest way to perform this implementation is to move the existing mirror out of the DS215 into the DS1515+ and perform a Synology Migration. This will bring the unit up exactly the way the DS215 was configured (with Shard Folders, Users, Access controls and Time Backup) in about one hour. It will not include BTFRS. *** Do not install the 3 new disks first. The old mirror will migrate Diskstation configuration if it is installed first.
Where is the configuration stored? On the volume?
Add new RAID 5 Disks -> Copy Shares from Independent Volume or Disk to RAID 5
Add the new disks and reformat the new RAID 5 volume as BTRFS instead of EXT4 and then move the shares over from the old volume.
If the users are accessing the data then it would be slower for them because they would be competing for a single spinning spindle. It is however possible that the whole thing could be done over a weekend without user impact – i.e. go in and do the initial migration to the DS1515+ last thing Friday, do the work necessary to move/format/move back the data remotely over the weekend. If this is done then it is imperative that the USB backup be made and updated before work starts.
File Server migration Support Summary
There are plenty of options when implementing a new file server. This is just one example for one Synology file server for many types of Network Attached Storage devices. Call us today for a network discovery. We will help find the right file server for your network.
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