Raid system on a pci-e card??

[Morgoth]

im wondering something like this, is it posible to turn it into a raid system? raid 5 i believe where it rebuilds it self when you insert a new harddisk, im limited on harddisk mounting space in my case, and this came up to my mind , how easy is it to make a raid system that auto backups my data? im using an SSD to run windows off and a pci-e SSD to run of my cad software and one of my fav games i got 2 large 1tb and 2tb disk, where i got my movies stored , my main focus is to backup my cad files becus those are very valuable to me i got a ton of SAS ports left open to use

 

[TheLostSwede]

Ok, first of all, go learn about RAID.

RAID 5 requires at least 4 drives, ideally 5 drives. So no, you can't do what you want with that card.

Also, unless you're happy with software RAID, you're going to need a RAID card for your PC.

 

[Morgoth]

oh thanks thats the response im looking for!

 

[TheLostSwede]

I guess you want something like this then http://www.silverstonetek.com.tw/product.php?pid=718&area=en
It even comes with an adapter from internal to external SAS.

 

[Morgoth]

yea but then on a pci-e card wit 4x drives instead of 2 , but i asume that device you posted is plug and play with good user friendly software?

 

[Static~Charge]

im limited on harddisk mounting space in my case

Since your computer chassis is low on drive bays, you should consider an external drive chassis to house your RAID.

my main focus is to backup my cad files becus those are very valuable to me i got a ton of SAS ports left open to use

If your goal is more storage capacity, then building a RAID setup with SSDs is a poor choice. The cost per GB of storage is extremely high. For example, a 4TB Samsung EVO 250 SSD is around $1,500 U.S. For that much money, you could buy three 12TB hard drives and implement a RAID-5 setup, yielding 24TB of storage.

Also, one big note: RAID is not a backup solution. Its goal is to reduce system downtime due to drive failures. Even with a RAID, you still need to back up your files. A RAID setup is worthless in the case of data corruption or multiple drive failures. Always back up your important data!

Ok, first of all, go learn about RAID.

RAID Level Tutorial to Understand RAID Technology
https://www.acnc.com/raid

RAID 5 requires at least 4 drives, ideally 5 drives.

Actually, RAID 5 requires a minimum of 3 drives: 2 for data, 1 for parity.

 

[Aquinus]

If you're using add-on cards that aren't actually RAID controllers, you would have to use software RAID which means no booting off of it directly. In Linux we can do some fancy things when it comes to where the bootloader and /boot partition exist so you can keep just the stuff required for initially booting like the kernel somewhere accessible and once the kernel loads up, root can be mounted on a software RAID but, I don't think Windows is that flexible.

If you do decide to do software RAID, remember that you're offloading parity calculations to the CPU and in a 4-disk RAID-5 setup with SSDs, I would expect that to be a bottleneck, or at the very least, something noticeable under heavy I/O load (in particular, writing to the array.) Also consider PCI-e bandwidth, 1x is probably not going to give performance that you would like, even more so if it's 1x @ 1.1.

Actually, RAID 5 requires a minimum of 3 drives: 2 for data, 1 for parity.

...and this. @Static~Charge got to it before I did.

 

[TheLostSwede]

Semantics, no-one does RAID 5 with 3 drives.

 

[Aquinus]

Semantics, no-one does RAID 5 with 3 drives.

Why? No redundancy is gained by having more drives. If anything, you're increasing your chances of losing two disks at once by having more disks. A system is safer with 3 disks in RAID and a hot spare standing by more than any number of drives in the array without one. The only benefit of running more drives in RAID-5 is for read performance and writes will only scale if compute can keep up with it and the obvious is more storage as you add more disks but, you still can only lose up to 1 disk, whether you have 3 or 8. There is no reason to not run 3-disks in RAID-5.

 

[TheLostSwede]

How is it safer with three disks? I think you don't understand how the redundancy data is split between the drives. It's not as if all the parity data is put on that third drive in your scenario, it's split between all the drives.
Also, on a 5 disk RAID 5, you can lose up to two drives without losing data.
But please, be my guest, run a 3 disk RAID 5 if that's what tickles your fancy.

 

[Bo$$]

3 disks in RAID and a hot spare standing

I'm not aware of any RAID number offering this.

As far as i can see RAID 5 or RAID10 would cover what the OP wants to do

 

[Aquinus]

I'm not aware of any RAID number offering this.

As far as i can see RAID 5 or RAID10 would cover what the OP wants to do

RAID-5 with 3 disks plus a fourth just sitting there as a hot spare is just RAID-5. There is no new RAID level to do this. Most raid controllers will let you say "this drive is a spare," and it will switch to it if there is a failure.

 

[Static~Charge]

I think you don't understand how the redundancy data is split between the drives. It's not as if all the parity data is put on that third drive in your scenario, it's split between all the drives.

You are correct. I should have said "With RAID 5, your usable storage capacity is 'number of drives - 1'. The parity overhead eats the storage capacity of one drive."

Also, on a 5 disk RAID 5, you can lose up to two drives without losing data.

Try it. You'll discover very quickly that your RAID-5 setup is inaccessible after two drive failures.

RAID-5 will tolerate only a single drive failure. RAID-6 will tolerate two drive failures. If you need more redundancy, then you have to add hot spares to the RAID.