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Discussion in 'DIRECTV HD DVR/Receiver Discussion' started by docderwood, Sep 28, 2012.
Can the HR line deal with RAID 1? Would this impact performance?
I have 2 HR's running RAID1 right now and tested another running RAID5. The one that was running RAID5 is now running RAID0. No issues at all.
Don't the risks of raid 0 greatly exceed the benefit?
What risk? There's no redundancy but I certainly don't see that as a risk.
It's no different than running off of one drive.
I'd see it as less reliable than running it off one. If either drive dies, you lose it. It seems to me there is a greater chance of that happening than one drive.
Of course we're not talking mission critical data here, and we know if the DVR dies, you lose everything essentially. But it's adding one more component to the mix.
that's right and he knew that
I don't see it as a risk at all. If you're running off 1 drive and 1 drive fails you lose everything. If you're running RAID0 and you lose 1 drive you lose everything. Like I said before, it's no different than running off one drive.
The odds of 1 of the 2 drives in a RAID0 array failing are the same as 1 drive in a 1 drive setup failing.
Please don't speak for me. I know what I said and meant it.
The odds of each single one failing is the same, but it's twice as likely as there are twice as many drives .
But a single failure is still a total loss. If it only takes a single drive failure to lose everything then the odds of you losing everything are the same as a single drive system. Same result, same odds, more space.
I use Enterprise Level drives, odds are lower.
Well, I was pretty good at statistics, and heartily disagree, but I think that's where we'll end up unless a math whiz comes along.
How is a single drive failure different than a single drive failure? :lol:
You're right , there is clearly demonstrated missing knowledge.
The rule is simple: total reliability is a product of multiplying all part's reliability.
Say one HDD has reliability equal 90% [0.9], then two same HDD will has total 0.81 ie 81%. Any engineer knows that and it shouldn't be discussed here.
If experience of the hardcore users is any indication, the DVR will likely die before either of the hard drives dies.
There are few engineers here so it bears repeating.
True, over the total lifetime of the two drives, and that is the calculation for RAID 0. However, the whole point of RAID 1 is to exploit the fact that the failure of a drive is likely to happen at any point over the entire expected lifetime of the drive (as stated in the MTBF rating). Therefore, the likelihood of both drives failing at the same time is vanishingly small. I honestly don't see the point of RAID 0 in a DVR use case. The DVRs don't need the extra drive performance, and buying two 1TB drives is more expensive than one 2TB drive.
Very possible. This is one reason I'm not doing a raid setup until the policy changes.
Validate that. Tell me what the odds are on hitting a home run the next time you get up after hitting a home run. And if you do hit a home run in successive at bats, what are the odds on hitting a third one?
Agreed and that's the problem we all face. Make the HRs and HDDs compatible with each other within an account and the problem goes away instantly.
Space. 2 x 2TB = 4TB.