Re: Anyone using XFS in production on > 20TiB volumes?

[Chris Wedgwood <cw@xxxxxxxx>]

On Wed, Dec 22, 2010 at 12:35:46PM -0500, Justin Piszcz wrote:

> Is this by specifying the sunit/swidth?

yes

> Can you elaborate on which paramters you modified?

i set both to match what the hw raid was doing, the lru that is my
brain doesn't have the detail anymore sorry

at a guess it was probably something like 64k chunk, 20 devices wide


the metadata performance difference between wrong and right is quite
noticable


> Yes and have it set to perform(ance).

be sure you have a bbu, there is a setting for force wc --- i wouldn't
do that

i would have it wc when the battery is good automatically disable it
when it's bad

i was able to buffer ~490MB of writes in the card without trying hard,
that's a lot of pain to get corrupted

> Going to be using 19HDD x 3TB Hiatchi 7200RPMs, (18HDD RAID-6 + 1
> hot spare).

are those 4k sector drives?  i ask because it's not clear if/how the
raid fw deals with these