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

Justin Piszcz
2010-12-22T17:33:49Z

On Wed, 22 Dec 2010, Chris Wedgwood wrote:

> On Wed, Dec 22, 2010 at 12:10:06PM -0500, Justin Piszcz wrote:
>
>> Do you have an example/of what you found?
>
> i don't have the numbers anymore, they are with a previous employer.
>
> basically using dbench (there were cifs NAS machines, so dbench seemed
> as good or bad as anything to test with) the performance was about 3x
> better between 'old' and 'new' with a small number of workers and
> about 10x better with a large number
Is this by specifying the sunit/swidth?
Can you elaborate on which paramters you modified?

>
> i don't know how much difference each of inode64 and getting the geom
> right made each, but bother were quite measurable in the graphs i made
> at the time
>
>
> from memory the machines are raid50 (4x (5+1)) with 2TB drives, so
> about 38TB usable on each one
>
> initially these machines were 3ware controllers and later on LSI (the
> two products lines have since merged so it's not clear how much
> difference that makes now)
>
> in testing 16GB for xfs_repair wasn't enough, so they were upped to
> 64GB, that's likely largely a result of the fact there were 100s of
> millions of small files (as well as some large ones)
Yikes =) Hopefully its better now?

>
>> Is it dependent on the RAID card?
>
> perhaps, do you have a BBU and enable WC? certainly we found the LSI
> cards to be faster in most cases than the (now old) 3ware

Yes and have it set to perform(ance).
Going to be using 19HDD x 3TB Hiatchi 7200RPMs, (18HDD RAID-6 + 1 hot spare).

>
> where i am now i use larger chassis and no hw raid cards, using sw
> raid on these works spectacularly well with the exception of burst of
> small seeky writes (which a BBU + wc soaks up quite well)
Interesting..