RAID5 with different HDD's ??

[kemperkipie]

Can I set up RAID5 with different sizes and speeds of HDD's?

I have
2 x 3.0 TB HDD's
and
3 x 2.0 TB HDD's

Intel Z77 Sata controller (Asus Sabertooth Z77)

Would RAID5 be possible
If yes, how will it operate? (What does it do with parity)
If no, why not?

Thanks

 

[manofchalk]

You can, but your losing out on capacity with the 3TB drives. They would effectively become 2TB.
There is also the general sentiment that your best of using identical drives in a RAID array

 

[kemperkipie]

Fact is, I already had 2 3 TB Drives, and have access to 20 x 2.0 TB Drives, (they were used but some are still good). The best ones are 2 WD and 1 Seagate. I want to use them for maximum storage for my media (movies and series, I make a database for my mediaserver)

At first I wanted to go JBOD, just to get 1 big volume, but if 1 drive fails, I'd lose everything. (Data is not important, but still sucks if it gets lost).

Would you suggest I get more 2.0TB drives to make a RAID5 volume? or JBOD with the 3.0TB drives and some 2.0TB drives?
Note that they are not all same brand 2.0TB drives.

If I would get RAID5, I could use the 3.0TB drives for my (software-)RAID1 storage on my ASmedia controller.

 

[manofchalk]

JBOD is where every disk is independent, the failure of one drive has no impact on another. Maybe your thinking RAID0 (or through software just mashing all the drives into one partition)?

Why are you looking for a RAID array? Knowing the purpose will help, no point talking about RAID5 when your after what RAID1 can give you.

 

[kemperkipie]

Why are you looking for a RAID array? Knowing the purpose will help,

I'm sorry,
I'm going to use it to store media (series, movies and music) which will be managed in a database to play on my mediaplayer. I would probably store some other things to let it function as NAS in my network anyway.
(I already have over 5.0TB media, but I am backing it up to other HDD's for transport for after I wiped all disks for RAID)

The data on the drives are not crucial. If the drives might fail, and I'd lose all data, it wouldn't matter much. It would just suck to download everything again.

JBOD is where every disk is independent, the failure of one drive has no impact on another. Maybe your thinking RAID0 (or through software just mashing all the drives into one partition)?

I thought that with JBOD on a RAID controller I could set a spanned volume over the multiple drives. (I know that JBOD means "Just a bunch of Disks", but I still thought it has more options)


To clear up the setup:
I have a Asus Sabertooth Z77 which gives me
- 6 x SATA (Intel Z77 - controller with RAID 0,1,5)
- 2 x SATA (ASmedia controller, no raid, data only, not bootable)

I would put my SSD with OS in the Intel Z77 port, along with 5 Data-drives
The data drives could be
2 x 3.0TB + 3 x 2.0TB (Spanned volume)
or
5 x 2.0TB (RAID5)

The ASmedia ports would contain 2 other data-drives. (2.0TB drives if I go for spanned, 3.0TB drives if I go for RAID5)
I would set those up for RAID1 with software-RAID. (Just windows disk management with mirrored volumes)
This would store my regular important data, such as documents and stuff for school.

no point talking about RAID5 when your after what RAID1 can give you.

RAID1 isn't an option, because the data is not that important and I want to have at least the 10TB storage. I am however, willing to give away the extra 2.0 TB for some data-security, since I would be using it as RAID1 on the other controller anyway.

Thanks for helping so far !

 

[Captain_WD]

Hey there kemperkipie,

If you plan on going with RAID 5, you shouldn't have problems but have in mind that it is not recommended to use different types of HDDs from different brands. Your drives' volumes will be limited to the volume of your smallest drive.
Choosing JBOD is not such a bad idea, if massive space is what you are looking for. The case where you lose everything when one drive fails is a type of JBOD called SPAN where all the drives are seen by the computer as one giant volume.
The other option, also known as JBOD is to have all your drives in the system separately as different volumes. This way even if one or more drives fail, the healthy ones remain completely usable.

Hope this helps. Feel free to text me if you have any questions,

Captain_WD.

 

[kemperkipie]

The case where you lose everything when one drive fails is a type of JBOD called SPAN where all the drives are seen by the computer as one giant volume.

This is actually the case I'm going for. I want the disks to be one volume. I'm glad you pointed out it is available on hardware RAID-controller.

If you plan on going with RAID 5, you shouldn't have problems but have in mind that it is not recommended to use different types of HDDs from different brands.

I might dig into my box of HDD's and find 5 of the same HDD's. But the problem is, the HDD's are not new, Some have ran over 20.000 hours. If I select the HDD's with the best health, it would be a mix of brands. (Some Seagates and some Western Digitals)

Would it be better to pick HDD's with better health from different brands, or all Western Digitals with less health? All the volumes would be 2.0TB

 

[Captain_WD]

Hello again,

Since JBOD Span is what you'd like, make sure you have a backup of all your important data somewhere else (on some of your other HDDs for example) because this option does not provide any redundancy.
It is always a better idea to use similar drives in RAID configurations. You can do a RAID 5 with 3 or more drives (5 is not a fixed number for this). And again, have in mind that with RAIDs (except JBOD) you are downsizing all your drives to the volume of your smallest one (if you have several 2 or 3TB ones and one 1TB, all your drives will have only 1TB usable each in the RAID). Also, with RAID 5 you lose some of the capacity due to the type of RAID and the redundancy that it provides.
Whichever drives you decide to use (older or newer ones), I would recommend that you run a WD Data Lifeguard Diagnostic check on them just to make sure they are fine and good for usage. Here's a link to that:
http://support.wdc.com/product/download.asp?groupid=810&sid=3&lang=en

If you have more questions, feel free to ask away.

Hope this helps you,

Captain_WD.

 

[kemperkipie]

I think I'm going for RAID5 with 5 Western Digital GreenPower drives. (2.0TB each). I would use the 2.0 TB Seagates to back-up my current data for transferring to the new system. And I would use my 3.0 TB Seagates for a software RAID1 (mirrored volume in Windows Disk management) on my ASmedia controller.

My OS is on a SSD on the remaining SATA-port (the sixth of my Intel Z77 controller).
Quick question,
How does my SSD run if controller is set to RAID, but it isn't in a RAID volume? Would it function like always, or would it miss some functions, like, is TRIM still working, etc.
I am aware that I need to re-install Windows.

Also, what are your honest thoughts on my conclusion?

Thanks for the help so far

 

[Captain_WD]

Your plan sounds great to me.
You shouldn't have problems with your SSD while your other drives are in RAID. According to Intel, the RST (Rapid Storage Technology) allows the TRIM on the SSD when it's outside the RAID so you shouldn't have problems with your Z77.
Overall, I think it looks good and having different RAIDs for different purposes gives you more redundancy. The WD Greens are not designed for RAIDs but they should work fine and would save you a lot of energy.
I'm glad that you found a good solution to your problem. If you have trouble setting it up or have any future issues with the RAIDs, feel free to contact me.

Cheers,

Captain_WD.