Warning about deduplication is not accurate

[ryao]

The warning introduced by 971808e about data duplication is not accurate. I did a write-up about why the rule of thumb provided is not accurate:

https://news.ycombinator.com/item?id=8437921

@FransUrbo I do not really want to have people spreading FUD quote the man page when I try to explain how things actually work. This message should be amended for accuracy.

[Sachiru]

So essentially the part in contention is: "It is generally recommended that you have \fIat least\fR 1.25 GB of RAM per 1 TB of storage when you enable deduplication."

What if it was worded this way: "A good rule of thumb is having \fIat least\fR 1.25 GB of RAM per 1 TB of storage when you enable deduplication, although the specific amount of RAM necessary may vary. For full details, please see https://news.ycombinator.com/item?id=8437921"

Would that be okay?

[ryao]

I will try to reword this later on the weekend. I think it would be best to include some equations and a table showing what the memory requirements are for different values.

[FransUrbo]

A good rule of thumb is having \fIat least\fR 1.25 GB of RAM per 1 TB of storage when you enable deduplication, although the specific amount of RAM necessary may vary. For full details, please see https://news.ycombinator.com/item?id=8437921"

Don't see how that differs from:

It is generally recommended that you have \fIat least\fR 1.25 GB of RAM per 1 TB of storage when you enable deduplication. But calculating the exact requirements is a somewhat complicated affair. Please see the \fBOracle Dedup Guide\fR for more information..

The warning introduced by 971808e about data duplication isn not accurate.

@ryao, there's nothing in the change/commit that's wrong. If you think otherwise, then

1. why did you not voice your opinion in #2754
2. please give the exact part that you think is wrong.

Yes, you point to proof that the 1GB/1TB is wrong, but "wrong" could mean many thing. IF you have that, you are "most likely" to manage (that's the "generally recommended" with the disclaimer "calculating the exact requirements …").

Yes, it's better to calculate it exactly, but putting to much detailed information in the manpage is in my opinion wrong. The point of the wording is to discourage anyone to enable dedup without understanding exactly what it entails. They can get that in many different places on the 'Net, including your page.

So "wrong" isn't necessarily "not right/correct"… I don't think 1GB/1TB is wrong, it's just not the truth, the whole truth and nothing BUT the truth… But that doesn't make it "wrong"..=

[GregorKopka]

Why not just get rid of the 2nd paragraph (the one with the 'rule') and stick the rest into the manpage?

[ryao]

A good rule of thumb is having \fIat least\fR 1.25 GB of RAM per 1 TB of storage when you enable deduplication, although the specific amount of RAM necessary may vary. For full details, please see https://news.ycombinator.com/item?id=8437921"
Don't see how that differs from:

It is generally recommended that you have \fIat least\fR 1.25 GB of RAM per 1 TB of storage when you enable deduplication. But calculating the exact requirements is a somewhat complicated affair. Please see the \fBOracle Dedup Guide\fR for more information..

The warning introduced by 971808e about data duplication isn not accurate.

@ryao, there's nothing in the change/commit that's wrong. If you think otherwise, then

1. why did you not voice your opinion in #2754
2. please give the exact part that you think is wrong.

1. I cannot review every single PR sent. I also sadly did not see your reply until now. There are so many issues in the repository that it is hard to keep track of them all.

2. Specifying a rule of thumb. We should be giving an equation.

[ryao]

Why not just get rid of the 2nd paragraph (the one with the 'rule') and stick the rest into the manpage?

That is not a terrible idea.