Work (really slow directory access on ext4)

[Arlie Stephens]

Hi Nick,

On Jul 29 2014, Nick Krause wrote:
> >> I was doing a vanilla ls. So was the original reporter, unless he has
> >> some really strange aliases.
> >>
> >>
> >> I'm afraid I'll be rather unpopular if I drop the caches on the system
> >> in question, creating a burst of poor performance, so my best bet is
> >> probably to see what I can do with ftrace on Monday, or perhaps
> >> partway through the weekend.
> >>
> >> There is normally a fair amount of disk activity going on - much of it
> >> writes. So I can expect cached blocks to age out in a reasonable time.
> >>
> > Arlie,
> > Whenever you get around to it is fine.
> > Just send me a log.
> > Cheers Nick
> 
> Arlie,
> just a friendly reminder can you try to send me the log this week.
> Regards Nick

I was just going to post an apology for going dark on you. I made one
attempt to capture the data yesterday, and messed up - no useful data
saved. And then half the world invaded my workspace with higher
priority tasks ;-)  

I'm going to make another attempt at it this morning.

On the good side, Vladis' observations of his mail directory have been
a great help. Now I know that simply being a large ext4 directory is
not the problem ;-)  I.e. ext4 really isn't as brain damaged as I
feared. (We had someone here who was initially sure that was it, and
he has more experience in linux server space than I do, so I took his
initial opinion at face value.) 

More soon, I hope.

-- 
Arlie

(Arlie Stephens					arlie at worldash.org)