Server Build - FreeNAS (1 Viewer)

[CyberSimian]

So you would use Drivepool on top of a standard TV server build?

Yes; it is not an exclusive operating system, it is simply an application that runs as a service on Windows.

Is it a one off cost or is it an annual license?

It is a one-off cost, I think. They probably have a "try before you buy" offer, that gives you 28 days use before you have to buy a licence or uninstall it. I tried that early last year, but at that time they had some problems with font sizes, resulting in some of the text on their panels being truncated. (In all fairness, I should point out that "MP Config" and "TV Server Config" have precisely the same problem -- they don't allow for the possibility that the user might be using a larger font; I stopped doing that when I decided to move permanently from WMC to MP. )

What sort of data recovery/protection do they offer, as it doesnt seem to follow the traditional RAID format?

The beauty of a drive pool is that the individual drives in the pool are simple NTFS disks that store files; there is no striping or spanning a file across multiple disks. So there is no performance increase for single files, although I believe that if you have file duplication enabled, and the disks in the pool are homogeneous (i.e. all the same speed), Stablebit will read simultaneously from both copies of the file to improve read speed.

The protection offered is by the user selecting file duplication, which causes the pool to store multiple copies of each file (typically two copies of each file, but you can choose more). Stablebit knows that it should store the copies on separate physical disks, so if one disk fails, the other copy of the file is available. After you have replaced the failing disk, Stablebit will re-duplicate all of the files that were on the failing disk.

This way i could just use my disks in a JBOD setup and run the cloud service as a scheduled backup and never have to worry about disk failure.

Is this practical for terabytes of data? How long would it take to upload? Months? Would you be in danger of exceeding your monthly limit? (Last month I got an early-warning email from my ISP that I was nearing my 10GB monthly limit. )

-- from CyberSimian in the UK

 

[eetaylog]

I have unlimited broadband through bt so I don't think it would be an issue, but you make a good point, I hadn't thought of how my isp might view this amount of traffic.

I could contact them and find out because quite frankly the cost of a two year unlimited data account with backblaze ($92) is ridiculously cheap. It would cost 4 times that for a 4 bay Nas, and that's before I've even bought any more disks.

I have just under 4Tb of media right now. If I could get this uploaded to an account then I could just add another 4Tb disk to my setup in a JBOD build and not have to worry about failed disks.

 

[eetaylog]

If I were in the market again for a mass-storage system, I am not sure that I would buy a NAS, The appealing alternative is a drive pool, and I would probably opt for the "Stablebit" drive pool software (they are very responsive to users on their forum). The advantages that I see are:

-- from CyberSimian in the UK

Been looking into this a bit more. Am i right in thinking that the file protection system it uses (where it duplicates whichever files you want) is the equivalent of striping? If ive got 2x2Tb drives and i want to protect all the files on there, i would only have 1Tb of usable space, right?

Thanks again.

 

[CyberSimian]

Am i right in thinking that the file protection system it uses (where it duplicates whichever files you want) is the equivalent of striping?

With "striping", a file's data blocks are distributed across different physical disks. In a simple RAID system (no protection), disk A would contain blocks 0, 2, 4, ..., and disk B would contain blocks 1, 3, 5, ... So if one disk fails, you lose everything. RAID5 uses n+1 disks to contain n disks worth of data, and so can recover from one disk failure. RAID6 uses n+2 disks to contain n disks worth of data, and so can recover from two disk failures.

With Stablebit's drive pool software, a file is written entirely on a single disk, but then that file is copied to a different physical disk in the pool so that the file exists in two places. So the drive pool uses 2*n disks to contain n disks worth of data (assuming all of the disks are the same size).

A RAID5 or RAID6 system uses fewer disks to store n disks worth of data than a drive pool. However, the drive pool allows you to unplug a single disk and connect it to a different computer and access all of the files on it (since it is a simple NTFS disk containing complete files); you cannot do that with a RAID disk (since each file is distributed over multiple disks).

If ive got 2x2Tb drives and i want to protect all the files on there, i would only have 1Tb of usable space, right?

With two 2TB disks in the pool, and file duplication for all files, you would have 2TB of usable space (effectively, the second drive becomes an image of the first).

-- from CyberSimian in the UK

 

[eetaylog]

But if Drivepool copies a duplicated file to a different disk, then surely half of the pool is taken up with copies (ie, half of the pool is made up of files, and the other half is the backup copies), and hence you would only get half the usable storage?

 

[CyberSimian]

But if Drivepool copies a duplicated file to a different disk, then surely half of the pool is taken up with copies (ie, half of the pool is made up of files, and the other half is the backup copies), and hence you would only get half the usable storage?

Yes, that is correct. But your prior post implied that you would get one quarter of the total storage: two 2TB disks giving 1TB of usable storage (was that a typo?). Two 2TB disks would give 2TB of usable storage.

-- from CyberSimian in the UK

 

[eetaylog]

Sorry, just spotted that, my mistake! I meant that 2 x 2Tb would leave 2Tb of usable.

So the main advantage of using Drivepool over RAID1 (which uses a similar backup format of a physical copy of every file) is that you can remove a disk and use it elsewhere because it keeps the backup on a seperate disk?

 

[CyberSimian]

So the main advantage of using Drivepool over RAID1 (which uses a similar backup format of a physical copy of every file) is that you can remove a disk and use it elsewhere because it keeps the backup on a separate disk?

For me, that is an important advantage of a drive pool. I am hesitant about becoming locked in to a proprietary data format. For example, if my Synology NAS developed a terminal problem, the only way that I could access my data would be to buy another Synology NAS and transfer the disks to it (even if I had already decided that I did not want another Synology NAS!).

But don't forget the other advantages:

(1) Can use disks of differing sizes.
(2) Can expand the size of the pool by simply plugging in another disk.

-- from CyberSimian in the UK

 

[eetaylog]

So the main advantage of using Drivepool over RAID1 (which uses a similar backup format of a physical copy of every file) is that you can remove a disk and use it elsewhere because it keeps the backup on a separate disk?

But don't forget the other advantages:

(1) Can use disks of differing sizes.
(2) Can expand the size of the pool by simply plugging in another disk.

-- from CyberSimian in the UK

You can do these things with a NAS cant you? I thought that with a NAS you could add new disks and increase the size of the RAID, and that you can have different size disks (though admittedly not all the disk space would be available depending on your RAID level).

 

[CyberSimian]

I thought that with a NAS you could add new disks and increase the size of the RAID,

Yes, up to the maximum number of bays that the NAS has. To increase space further, you then have to replace smaller disks with bigger disks, or buy another NAS. With a drive pool, you simply need a free USB socket, and no disks have to be replaced.

Example: if you purchased a two-bay NAS to contain your two 2TB disks, and you later ran out of space, you would have to retire your 2TB disks, and replace them with 4TB or 6TB disks. With a drive pool you could continue to use the 2TB disks, while adding 4TB or 6TB disks as you needed them.

you can have different size disks (though admittedly not all the disk space would be available depending on your RAID level)

Yes. Synology offer a "Synology Hybrid RAID" format, which makes usable some of the space that is normally unusable, but at the cost of making the data format proprietary. The following "RAID Size Calculator" is a useful tool to see how much usable space different disk sizes and RAID types would give you:

https://www.synology.com/en-us/support/RAID_calculator

Note: other NAS makers are available!

-- from CyberSimian in the UK