StableBit or Raid 5?

[platinumjsi]

Ok a little background, Currently I have 4x 2tb drives in raid 5 which are almost full so I am looking to purcahse a new set of drives and move my data over.

I want everything on the drives to be protected.

A number of friends have recomended StableBit to me but I am not sure if I would see any benifit over raid 5?

 

From what I can tell StableBit looks a great soloution to pool a number of drives that may not bee the same capaicty and when you perhaps dont need full protection of all the files?

 

Few questions though : 

 

Can you set duplication for the whole pool rather than having to select each folder?

 

Will stablebit use more space than raid 5 when duplicating all files?

 

I do like the look of the drive scanner software though, can this be used without Stablebit?

 

Thanks

[Christopher (Drashna)]

Can you set duplication for the whole pool rather than having to select each folder?

Absolutely. And you can then disable duplication for specific folders if you want.

To enable this, it's located in "Pool Options" -> Data Protection. Enable the "Pool File Duplication".

 

This enables duplication on the root of the pool, and this setting gets inherited to all subfolders (except for the ones you explicitly change it for).

 

Will stablebit use more space than raid 5 when duplicating all files?

Yes.

 

To answer this, and the "protection"/benefit over RAID question:

The duplication option is a 1:1 file based mirroring (aka duplication). This means that you have two copies of any duplicated file, located on different disks.

 

This means that duplication will use up more space than a parity array (RAID 5). However, because we store the files on normal NTFS volumes, you can access the data in any OS, and even on different systems.

Additionally, we do use "Read Striping" to boost the performance of reads. Check out this link for details on Read Striping (and some other performance features):

http://stablebit.com/Support/DrivePool/2.X/Manual?Section=Performance%20Options

 

 

Another point here is that parity isn't necessarily protecting your data. Specifically:

Did you buy all of your drives at the same time?

Have you ever swapped out any of the drives, or have a schedule set up to do so (with spare/new drives?

 

The reason I ask, is that if you bought all the drives at the same time, they're probably from the same batch. And if there is a defect on one of the drives, there is a high chance that the other drives will have the same defect. This means that if one drive fails, the higher load on the other drives could trigger an issue on the other disks, triggering a catastrophic failure.

To prevent this, enterprises regularly schedule replacements of disks, to prevent something like this from happening. However, in home use... this rarely ever happens.

 

I do like the look of the drive scanner software though, can this be used without Stablebit?

I'm assuming that you mean if you can use StableBit Scanner without StableBit DrivePool. And yes, absolutely. The benefits of using StableBit Scanner remain regardless of the setup you're using. The monthly surface and file system scans are very good for your system. Even on a RAID array.

In fact, the surface scan may cause the disks in the array (or the RAID controller) to identify and fix problem sections of the disk before they manifest as errors.

 

However, depending on the setup, StableBit Scanner may not be able to get SMART data from all of your disks. Specifically, from disks in a RAID array (depending on how the array was created).

 

 

[RobbieH]

Another advantage of Drivepool is that if you have a specific folder that you want extra protection for, like pictures, you can set it to duplicate across more than just two drives. So you could have three copies if you wanted.

[Umfriend]

Which would not help you against a number of things. I would recommend offsite backups for important data (all data actually to the extent possible).

[airjrdn]

In addition to what others have said (and what RobbieH said is something I'd say is very important), I think your second sentence is key here...

 

Currently I have 4x 2tb drives in raid 5 which are almost full so I am looking to purcahse a new set of drives and move my data over.

 

With DrivePool, you'd simply buy another disk (or more - of ANY size) and increase the size of the pool.  There'd be no need to replace the entire array/pool all at once, spend time copying the data, etc.

[RobbieH]

Which would not help you against a number of things. I would recommend offsite backups for important data (all data actually to the extent possible).

I certainly did not mean to imply that this was a replacement for offsite backups, but one of the complaints I consistently hear about RAID5 is the fact that losing two drives means you lose your data - Drivepool gives you a way to duplicate in a manner that would mitigate this risk.

[Umfriend]

Yeah, I may be nitpicking. Thing is, with DP, if you lose X HDD where X is the duplication factor then you may have lost data as well. So I am not so sure that DP is really better than RAID 5 in that respect. But yeah, even with the increased overhead of DP with duplication over RAID 5 or 6, I favor DP over RAID (0, 1, 5, 6 or 10).

[Christopher (Drashna)]

I certainly did not mean to imply that this was a replacement for offsite backups, but one of the complaints I consistently hear about RAID5 is the fact that losing two drives means you lose your data - Drivepool gives you a way to duplicate in a manner that would mitigate this risk.

Precisely.

 

DrivePool can set the duplciation levels to much higher than just x2.  

Additionally, if a RAID5 array loses two disk, you lose EVERYTHING in the array. WIth DrivePool, you only lose what was one the disks. So if you have a lot of disks, you will still retain at least some of the data. This makes recovering data a lot easier, as you only have to replace a disk or two worth of content, instead of the entire array.