Re: Question about HDFS capacity and remaining

[Sagar Naik <sn...@attributor.com>]

Hi Brian,
Is it possible to publish these test results along with configuration 
options ?

-Sagar

Brian Bockelman wrote:
> For what it's worth, our organization did extensive tests on many 
> filesystems benchmarking their performance when they are 90 - 95% full.
>
> Only XFS retained most of its performance when it was "mostly full" 
> (ext4 was not tested)... so, if you are thinking of pushing things to 
> the limits, that might be something worth considering.
>
> Brian
>
> On Jan 30, 2009, at 11:18 AM, stephen mulcahy wrote:
>
>>
>> Bryan Duxbury wrote:
>>> Hm, very interesting. Didn't know about that. What's the purpose of 
>>> the reservation? Just to give root preference or leave wiggle room? 
>>> If it's not strictly necessary it seems like it would make sense to 
>>> reduce it to essentially 0%.
>>
>> AFAIK It is needed for defragmentation / fsck to work properly and 
>> your filesystem performance will degrade a lot if you reduce this to 
>> 0% (but I'd love to hear otherwise :)
>>
>> -stephen
>