[Lustre-discuss] Is there a way to set lru_size and have it stick?

[Lundgren, Andrew]

I have tried using:

# lctl conf_param content-MDT0000.osc.lru_size=800

Seen this in the log: 
Oct 12 18:35:36 abcd0202 kernel: Lustre: Modifying parameter content-MDT0000-mdc.osc.lru_size in log content-client
Oct 12 18:35:36 abcd0202 kernel: Lustre: Skipped 1 previous similar message

But then on the clients, the lru_size doesn't seem to change:

OSS # cat ./fs/lustre/ldlm/namespaces/*/lru_size
33
0
0
0
1
0
1
200

I have also set it for the OST individually from the MDS.  It doesn't seem to do anything for the other machines.

Is this a permanently tunable parameter, or am I just specifying the wrong setting?

> -----Original Message-----
> From: Bernd Schubert [mailto:bs_lists at aakef.fastmail.fm]
> Sent: Monday, October 12, 2009 11:21 AM
> To: lustre-discuss at lists.lustre.org
> Cc: Andreas Dilger; Lundgren, Andrew
> Subject: Re: [Lustre-discuss] Is there a way to set lru_size and have
> it stick?
> 
> On Saturday 10 October 2009, Andreas Dilger wrote:
> > On 8-Oct-09, at 22:28, Lundgren, Andrew wrote:
> > > Is there a way to set the lru_size to a fixed value and have it
> stay
> > > that way across mounts?
> > >
> > > I know it can be set using:
> > > $ lctl set_param ldlm.namespaces.*osc*.lru_size=$((NR_CPU*100))
> > > But that isn’t retained across a reboot.
> >
> > "lctl set_param" is only for temporary tunable setting.  You can use
> > "lctl conf_param" to set a permanent tunable.
> 
> Would you mind to provide an example line? I never understood the logic
> of
> lctl conf_param. This fails:
> 
> lctl conf_param ldlm.namespaces.testfs-OST0002-osc.lru_size=800
> error: conf_param: Invalid argument
> 
> 
> And this as well
> 
> lctl conf_param testfs-MDT0000.ldlm.namespaces.testfs-OST0002-
> osc.lru_size=800
> 
> 
> Thanks,
> Bernd
> 
> --
> Bernd Schubert
> DataDirect Networks