[BORIStheBLADE]

So since I'm in the process of building a new server I have been reading about all my options to use with window. Why do I want to use window? Well I have a copy floating around and would prefer to use it.

Since everyone seems to recommend Unraid and Flexraid now I wanted to read up on how they work. I know Unraid doesn't run on windows, but a lot suggest it. It seems to me that a lot of users like the idea of parity instead of Raid stripping. I understand the reason and correct me if I'm thinking it's basically because if you lose one drive you have access to the others. So with that in mind I was also reading about Windows 8 new features that seem to use parity with the new Storage Spaces. It seems pretty new to the block so I haven't seen much info and user feedback about experiences.

So what I'm wonder is why can't I, if possible span two drives in Windows then install two more, span them then have the second pair mirror the first? I don't know much about all the raid and had to ask.

[BORIStheBLADE]

Ok, so I did some reading and it looks like what I'm explaining is RAID 0+1. Any cons to going with it?

[tesona1977]

right the scenario your described is a raid10 or raid01 (depending on whats setup first)

cons:
* money? you loose space of two drives ... any reason you prefer raid10 over raid5?

[PatrickVogeli]

If you want to use windows, you have the alternative of Snapraid (free) or flexraid (paying), both have parity protection and no stripping, but in flexraid you can set it up so that you only one big drive and in snapraid you can't

[Djfalconer]

Correct me if I'm wrong but doesn't RAID 5 suffer from a performance issue, unless you have an expensive RAID card? whereas RAID 10 is fast enough to be used for video editing etc (I have seen this done but if I'm wrong feel free to correct me).

[BORIStheBLADE]

right the scenario your described is a raid10 or raid01 (depending on whats setup first)

cons:
* money? you loose space of two drives ... any reason you prefer raid10 over raid5?

With RAID 5 I believe if one drive fails you lose access to the other drive its span with.

[goAMinD]

If a RAID 5 setup crashes with ONE disk you are able to rebuild. If two disks dies at same time you're in trouble since the parity distribution lies on all disks, hence to many lost parity bits.

[tesona1977]

you suffer from a "write penalty" because of the parity checksums computed by your host cpu. that's why "writes" does not scale like "reads" in a raid 5/6 setup

you should always prefer raid 10/01 over raid5/6 ... the big con is that you always "loose" half of your hdds because your data has to be mirrored to another hdd all the time.

rule of thumb:

raid 10: <hdd count>/2 -> raid 10 with 10 hdds you loose 50% of discspace because of mirrored data
raid 5: <hdd count> - 1 -> raid 5 with 10 hdd you loose only one hdd for parity information
raid 6: <hdd count> - 2 -> raid 6 with 10 hdd you loose two hdds for parity information

if you got >= 4GB HDD space you should switch from raid 5 to raid 6 otherwise you risk data loss in rebuild phase