[CentOS-virt] Slightly OT: FakeRaid or Software Raid

Ben M.

centos at rivint.com
Wed Dec 2 21:49:18 UTC 2009

Thanks. The portability bonus is a big one. Just two other questions I 

- Raid1 entirely in dom0?
- Will RE type HDs be bad or good in this circumstance? I buy RE types 
but have recently become aware of the possibility where TLER 
(Time-Limited Error Recovery) can be an issue when run outside of a 
Raid, e.g. alone on desktop machine.

I do have a utility where I can change the HDs firmware setting to get 
turn it off or on for either Read or Write delays.

Christopher G. Stach II wrote:
> ----- "Ben M." <centos at rivint.com> wrote:
>> I have had great luck with nvidia fakeraid on RAID1, but I see there
>> are 
>> preferences for software raid. I have very little hands on with full 
>> Linux software RAID and that was about 14 years ago.
> MD RAID. I'd even opt for MD RAID over a lot of hardware implementations. This writeup summarizes a bit of why:
> http://jeremy.zawodny.com/blog/archives/008696.html
> Hardware RAID's performance is obviously going to be better, but it's only worth it if you *need* it (more than ~8 disks, parity). If you're just doing RAID 0, 1, or 10 in a single box and you're not pushing it to its limits as a DB server or benchmarking and going over it with a magnifying glass, you probably won't notice a difference in performance.
> I'll take fewer moving parts and portability.
> As someone already said, dmraid is done in software, too. "Fakeraid" is basically the same as MD RAID, but with an extra piece of hardware and extra logic bits to fail.

More information about the CentOS-virt mailing list