Question How many bays and HD should I get if I buy a Synology NAS?

[modeonoff]

Hi, I have decided to buy a Synology NAS. At first I planned to buy a 4-bay one. However, I don't know how much disk space and drives I will end up in 5 years. Not sure if I should get a 5 or 6-bay NAS instead of a 4-bay NAS which could allow expansion of more drives via eSATA.
Currently, I have to backup the following:

1. Work PC with a 2TB main disk. Used about 1.25TB already.
2. iPad with a 256GB storage (generates about 256GB of photos and videos every 10 months or so)
3. Time machine backup of a Mac I already sold (about 1TB SSD)
4. iPhone 128GB
5. Linux development system 1TB
6. Old drives (Windows, Max, Linux) made over the past 20 years. Maybe about 1TB in total. Not decided if I should copy the data to the NAS or just leave them in the drawers.

Given the above usage, is a 4-bay NAS sufficient? How much storage/drive do you recommend if I just buy one or two drives initially?

If I buy a 4-bay NAS with one 4TB drive initially. Is it easy to add higher capacity drives later and change the RAID configuration?
Is it a bad idea to mix drives of different sizes? For example, one 4TB, two to three 6 or 8TB HDD later?

Note that one reason I don't get one 8 or 10TB HDD at the beginning is that besides the cost, the higher the capacity, the noisier it is. Is this really true?

 

[USAFRet]

Mixing drive sizes and RAID.
Not really.

What type RAID array, and WHY?

 

[modeonoff]

Do you mean it is not a good idea to mix drive sizes?

I probably end up with RAID 5 but don't want to spend so much money on the NAS system all at once.
I also don't have a plan to buy a second NAS to backup the first.

 

[USAFRet]

Do you mean it is not a good idea to mix drive sizes?

I probably end up with RAID 5 but don't want to spend so much money on the NAS system all at once.
I also don't have a plan to buy a second NAS to backup the first.

Size of a RAID array is totally dependent on drive sizes.

ex:
RAID 5, 4x4TB = 12TB RAID array.

Swap one of the 4TB for an 8TB...you still have a 12TB array.

Not until ALL 4 drives were swapped for 8TB would you see a larger array.
4 x 8TB + RAID 5 = 24TB.


Starting with a single 4TB and adding 2-3 drives later for a RAID 5 means a full reformat of all the drives and data.

 

[modeonoff]

A full reformat does not sound good. On Windows and MAC, each time I reformat a drive, the useable size of the drive reduces. Does this also happen in the case of NAS?

What if I have 4xwhatever size I decide at the beginning. Then later on if I want more capacity, add an eSATA expansion box with drives of the same size or larger size? Will reformatting of those existing four HDD still be required?

 

[USAFRet]

A full reformat does not sound good. On Windows and MAC, each time I reformat a drive, the useable size of the drive reduces. Does this also happen in the case of NAS?

On Windows, no it does not.
Unless you did something wrong.

What if I have 4xwhatever size I decide at the beginning. Then later on if I want more capacity, add an eSATA expansion box with drives of the same size or larger size? Will reformatting of those existing four HDD still be required?

If you start with 4x4TB, and configure it as a RAID 5, then you have 12TB.
Adding some other box later does not require a reformat of that RAID array, unless your NAS allows external drives to be part of the array, and you want to configure it thusly.

In my NAS, I have the main QNAP.
4 individual drives of varying sizes. 480GB, 8TB, 14TB, 18TB.
No RAID.
Each drive is its own Volume and use.

Externally, a 4 bay TR-004.
4x4TB in JBOD config.

That external box is simply another Volume.

 

[punkncat]

I have a two bay Synology that I purchased to do backups with. It stated that there was "hot swap" ability with the unit that would allow me to run mirrored drives and if one failed I could repopulate and backup again. I have come to find that changing the drive causes the unit to want to reformat and thus lose my data. It also writes in a format that a PC cannot read, so just removing the good drive and popping into a computer to glean data from is off the table.

I am FAR from a well versed user of this unit, but my experience with it so far would have been game changing insomuch as a decision to BUY one. I much prefer using a low powered PC based NAS solution than something proprietary like this. YMMV.
I swapped my unit from critical mirror backups to a standard movie and file share and in that position has been quite reliable, if nothing else.

 

[modeonoff]

By "other box", do you mean a 2nd NAS or something like the DX517? I am talking about the latter.

DX517 | Synology Inc.

In general, how is the performance of a 6-bay NAS compared with a 4-bay NAS + 2 bays from an expansion unit such as a DX517?

 

[modeonoff]

I have a two bay Synology that I purchased to do backups with. It stated that there was "hot swap" ability with the unit that would allow me to run mirrored drives and if one failed I could repopulate and backup again. I have come to find that changing the drive causes the unit to want to reformat and thus lose my data.

By losing data, do you mean HD size reduces or in that changing drive process, something went wrong and you lost data?

 

[USAFRet]

By "other box", do you mean a 2nd NAS or something like the DX517? I am talking about the latter.

DX517 | Synology Inc.

In general, how is the performance of a 6-bay NAS compared with a 4-bay NAS + 2 bays from an expansion unit such as a DX517?

"other box" can be anything from some USB external, to a whole other NAS.
Often, another NAS can be integrated into the existing Volume.
This depends on the NAS OS and the specifics of the external thing you attach.

Performance?
All the same.
The main limiting factor would be the network, not the NAS itself.

 

[punkncat]

As I mentioned, it states you can hot swap a bad drive and repopulate from the good drive such as not to lose mirror/data. I have at this point had three occasions where I needed to swap a bad drive and/or reconfigure the disks being used and each time (same type/size drives) I lost all my data because the unit refused to repair and repopulate the new disk. I am not going so far as to say it couldn't be user error, but based on the instructions as I perceived them, it went NOTHING like the sales literature stated. Each time the new disk remained out of use and not backing up.

I have a DS220j, which is a bit different than what you are asking about, but figured you might be interested in the issue since you are considering this product. In my own knowledge base and experience I would have continued using the Windows machine I had doing this before. The benefits of the new unit being small footprint, low power use, and quiet...well as quiet as HDD writing in mirror are anyway.

 

[USAFRet]

My QNAP has hotswap.
I've tried it, and it works.

Originally, RAID 5, 4x3TB drives. 9TB array.

Upgrading to 4x4TB.
I swapped one of them, and the array rebuilt itself.
Still 9TB.

For the other 3 drives, I powered off and swapped.
At the end, with the final 4TB and rebuild, it then saw the full 12TB array.

Rebuild time was approx 1.5 hours per TB of actual data.
There was approx 6TB data in the array, so about 9 hours rebuild time for each of the 4 new drives.

I've since done away with the RAID 5 completely, so....

 

[modeonoff]

As I mentioned, it states you can hot swap a bad drive and repopulate from the good drive such as not to lose mirror/data. I have at this point had three occasions where I needed to swap a bad drive and/or reconfigure the disks being used and each time (same type/size drives) I lost all my data because the unit refused to repair and repopulate the new disk. I am not going so far as to say it couldn't be user error, but based on the instructions as I perceived them, it went NOTHING like the sales literature stated. Each time the new disk remained out of use and not backing up.

That does not sound good. I thought mirroring prevents this from happening. Are there things we could do to prevent this from happening?

 

[USAFRet]

That does not sound good. I thought mirroring prevents this from happening. Are there things we could do to prevent this from happening?

Have a real backup in case things like that DO happen.
A mirror or RAID 1 is not a backup.

 

[punkncat]

Have a real backup in case things like that DO happen.
A mirror or RAID 1 is not a backup.

Yup, I utilize storage in (3) different places actively, have another drive that I use in an external enclosure to do backups to on a semi regular schedule, and also utilize the cloud for certain things I deem critical in two different ways. Not to be overlooked, I also keep CD and DVD backups of some things. This last part saved my entire music collection...

 

[modeonoff]

Is it true that a NAS can generally last for 10 years? Between 4 and 5 bays, which is recommended?

 

[USAFRet]

Is it true that a NAS can generally last for 10 years? Between 4 and 5 bays, which is recommended?

Mine will be 6 years old in a couple weeks. 24/7 ops, unless I go on vacation.
Shows no signs of slowing down.

Basically, it is a PC.

 

[modeonoff]

Will there be major tech upgrade in the field of NAS that is worth to wait for another two or so years? For example, if I were to build a new PC, I would just skip PCIe4 system and wait for PCIe5 and USB4 ver2.

 

[USAFRet]

Will there be major tech upgrade in the field of NAS that is worth to wait for another two or so years? For example, if I were to build a new PC, I would just skip PCIe4 system and wait for PCIe5 and USB4 ver2.

No.

 

[modeonoff]

Thanks. Since I have waited for over two years already, maybe this is time to buy.

 

[modeonoff]

Have a real backup in case things like that DO happen.
A mirror or RAID 1 is not a backup.

I thought one of the selling points for NAS is that using mirroring/RAID, if one drive dies, data are not lost. However, this is the second story I read about data lost in NAS. It looks like if something bad happened, data in all drives inside a NAS could all be lost which is worse than backing up using several external drives. Is that right?

 

[USAFRet]

I thought one of the selling points for NAS is that using mirroring/RAID, if one drive dies, data are not lost. However, this is the second story I read about data lost in NAS. It looks like if something bad happened, data in all drives inside a NAS could all be lost which is worse than backing up using several external drives. Is that right?

You're misunderstanding what a mirror or RAID 1 is and does.

Yes, if one drive is physically lost, the data still resides on the other and is accessible.
But this is only for uninterrupted uptime.

It does nothing for all the other forms of data loss.

If you accidentally delete something, the RAID 1 does nothing for that.
Ransomware, corruption, theft, fire, accidental formatting...

The user and OS sees one copy of a file.

You can have a RAID 1 for the physical drive redundancy.
But you also need a real backup for data redundancy.

 

[modeonoff]

I am a bit confused. So what is the point of buying more hard drives for mirroring/RAID such as RAID 5? The total cost to run NAS seems to add up very quickly.
Isn't it better to buy just 1-2 hard drives for NAS and 1-2 for external backup rather than 4-5 hard drives all in a NAS with RAID 5?

 

[USAFRet]

I am a bit confused. So what is the point of buying more hard drives for mirroring/RAID such as RAID 5? Isn't it better to buy just 1-2 hard drives for NAS and 1-2 for external backup rather than 4-5 hard drives all in a NAS with RAID 5?

Physical drive redundancy.

But, in the regular consumer realm...RAID of any type is generally not needed.
A good backup routine is far far better.

In mine:
NAS Host - 4 bay QNAP 453A
TR-004 external 4 bay enclosure

In the 453A NAS Host:
Disk 1 - 8TB - Holds nightly/weekly backups for all the house PCs
Disk 2 - 14TB - Holds 24/7 video from the house surveillance cameras. Each camera consumes 1.2TB per 30 days...soon to add a 3rd and 4th camera.
Disk 3 - 18TB - Main storage.
Disk 4 - 480GB SSD - System drive and small shared storage

Each an individual Storage Pool and Volume. No "RAID" needed.


In the TR-004
4x4TB, JBOD so it is seen as a single volume
16TB available space.
This serves as the backup for most of what is in the NAS. Weekly one way sync from the NAS Host.
Movie and Music folders duplicated in other places.



And originally, I did start this with a 4 drive RAID 5. Mainly just to test the concept.
But with a good backup, and tolerance for recovery time....the RAID was not needed at all.



All data exists in at least 2 copies, sometimes 4 copies.

 

[modeonoff]

Thanks for the analysis. So just treat the NAS as one type of storage that could also lose data like other types of storage, rather than some kind of magical box that can prevent data lost even 1-2 drive(s) fail.