RAID 1 + single drives. Onboard on not?

[JohnThomas]

Hi all,

We have an Asus P8H77-V LE with an Intel H77 chipset on it, two 500GB disks (we need these disks to be separate volumes), a DVD unit and one trashed 3TB disk.

The doomed 3TB has (ok, had) a growing photo collection on it. (yes, fortunately we have a backup and only some non-important items were lost).

What we want to do is to provide better data protection for the new 3TB volume which we want to build.

For this, we think at a RAID1 solution with two 3TB disks, but some questions arise:

1. The onboard H77 chipset is enough to handle the array (performance wise wrt CPU hit), taking in account that the CPU (an i5-3550 @ 3.3GHz) isn't very loaded and the writes on the 3TB volume are rare (once big batch every few days) but reads are more often - something like a low-usage file server?

1.a. If we go with H77 can we have the above RAID 1 array together with two other single drives (the 500GB disks which we mentioned above) - IOW 3 (three) storage volumes and the DVD drive? (for conformity, the H77 has 6 SATA ports, but I'm not really sure what configuration(s) it supports)

1.a.a. (nested question to the nested question...) If the H77 chipset supports RAID arrays together with single drives (which I think it does, but I asked to be sure) then what's the difference between [IDE] and [RAID] values in the BIOS config item called "SATA Mode Selection"? (IOW, I know what's the difference between [AHCI] and [RAID] or [IDE] but I think that [RAID] superseeds the [IDE]. Am I wrong?)

2. If you think that there are another better solution, can you recommend an alternative and/or another rather cheap (ok, we'll pay if price/performance/features is good) & basic & reliable hardware controller to attach our RAID 1 on it? (...now I'm thinking that the biggest hurdle is to support 3TB units...).

TIA for your feedback!

 

[_Rick_]

Just use software RAID and keep the drives in AHCI mode.
Controller hardware is just another single point of failure, and usually less reliable than going the software route. For RAID1 performance isn't an issue either.
Software RAID is more flexible, you can easily set it it up in the OS, you won't need to load a RAID opROM during boot....The advantages are endless.

The only advantage of the H77-integrated RAID (which is just software RAID) is that you can boot off of RAID0 or RAID5. There is literally no reason to use it for RAID1.

If you're running Linux, use mdadm (H77 will just be dm-raid anyway...), if it's Windows, just use the Volume Manager to create a mirrored volume.

 

[GPz1100]

I've been using a raid0 arrangement on 2 1tb drives for well over a year. The array was setup using the onboard intel chipset raid. The volume was used as a boot/system drive. This was originally set up on a P35/ICH9R chipset. Recently changed boards to the what's in the sig, Z77 based. The array carried over (using volume as a data disk now) without issue. I also have a number of individual drives plugged into the intel sata ports. They coexist without issues.

1.a.a, ide/ahci/raid is more for compatibility. If you're using some OS like maybe win xp, without ahci/raid support, you'd set it to IDE mode. This enables the ide emulation which allows the sata drives to appear as ide to the system/OS.

As for going chipset raid or OS raid. I don't know. I've had good experience with chipset raid, so i'm sticking with that. Also, no issues imaging a chipset raid with acronis backup/restore. I would expect current versions to handle windows raid arrays just as easily, but have no experience in doing so.

 

[_Rick_]

I would expect current versions to handle windows raid arrays just as easily, but have no experience in doing so.

RAID 1 is pretty transparent - no magic needed. Each disk will look like any other disk, and function by itself. So there's no challenge to handle the array at all - just treat each disk as a single disk.

 

[MrK6]

As Rick mentioned, hardware RAID is just another point of failure and if you're using RAID more for the redundancy over any performance advantage, software RAID 1 is the way to go. If you wanted to boot off them, you might have to go hardware, but from what you've described it doesn't seem like that's the case.

I'm currently using two Samsung F4 2TB drives in RAID 1 for my data storage. It's simply set up through Windows 7's Disk Management. Even after reinstalling the OS, Windows will recognize the RAID 1 and only have to reassign the drives to the new OS and resync the drives (which can take some time depending on the size, but it'll be done overnight). It's simple and safe, which is why I use it.

 

[JohnThomas]

RAID 1 is pretty transparent - no magic needed. Each disk will look like any other disk, and function by itself. So there's no challenge to handle the array at all - just treat each disk as a single disk.

_Rick_ you're a little bit fuzzy here. I confess I don't have any experience with Windows's software RAID, but I work(ed) enough with RAID cards, so I'm used to have disks 1, 2, (3, 4... etc.) attached to a RAID card but the OS will see a single disk - let's say disk D (the classical concept of an array, as we all know)

However, what do you say can be interpreted that in Windows Explorer (and not in Windows Disk Manager only) - or in any other Windoze program which uses the Disk API calls for that matter - the RAID1 "ensemble" which is configured in OS's Disk Manager will appear as two disks (let's say D and E) but having the same data?

...hmmm.... ....mhmmm... :\ can you (or anyone else) clarify a little?

Anyway, thanks a lot to all for your feedback. Very constructive.

 

[MrK6]

However, what do you say can be interpreted that in Windows Explorer (and not in Windows Disk Manager only) - or in any other Windoze program which uses the Disk API calls for that matter - the RAID1 "ensemble" which is configured in OS's Disk Manager will appear as two disks (let's say D and E) but having the same data?

...hmmm.... ....mhmmm... :\ can you (or anyone else) clarify a little?

Anyway, thanks a lot to all for your feedback. Very constructive.

If you set up software RAID, Windows Disk Manager will see the individual disks, but they'll be linked, synchronized, and labeled mirrored and have a cranberry colored bar covering the entire partition. In anything else, Windows Explorer, etc., they'll be seen as a single disk (D: in my case). For example, here are my disks as seen in Windows Disk Manager:

and here they are in Windows Explorer: