Inode usage

Inode usage

[Stein M. Hugubakken]

Hi!

I have a lot of free inodes on my xfs-partitions and was wondering about 
what impact this has on performance or memory?

Here is output from 'df':
df -ih
Filesystem            Inodes   IUsed   IFree IUse% Mounted on
/dev/hda2               5,1M    129K    5,0M    3% /
/dev/hda3                31M     54K     31M    1% /home

df -h
Filesystem            Size  Used Avail Use% Mounted on
/dev/hda2             5,1G  2,8G  2,4G  55% /
/dev/hda3              31G   18G   13G  59% /home

With xfs_growfs -m I can adjust the amount of free inodes, but it seems 
I can't change it for the root-partition, why is that a problem?

Kind regards
Stein

Re: Inode usage

[David Chinner]

On Thu, Apr 19, 2007 at 10:28:46AM +0200, Stein M. Hugubakken wrote:
> Hi!
> 
> I have a lot of free inodes on my xfs-partitions and was wondering about 
> what impact this has on performance or memory?

None.  The number of free inodes is a made up number. ;)

XFS dynamically allocates and frees inodes, so the number of free
inodes is determined by working out how many inodes
could be allocated in the remaining free space you have.
It's a theoretical maximum....

> Here is output from 'df':
> df -ih
> Filesystem            Inodes   IUsed   IFree IUse% Mounted on
> /dev/hda2               5,1M    129K    5,0M    3% /
> /dev/hda3                31M     54K     31M    1% /home
> 
> df -h
> Filesystem            Size  Used Avail Use% Mounted on
> /dev/hda2             5,1G  2,8G  2,4G  55% /
> /dev/hda3              31G   18G   13G  59% /home
> 
> With xfs_growfs -m I can adjust the amount of free inodes, but it seems 
> I can't change it for the root-partition, why is that a problem?

Works for me....

Cheers,

Dave.
-- 
Dave Chinner
Principal Engineer
SGI Australian Software Group

Re: Inode usage

[Daniele P.]

On Thursday 19 April 2007 15:14, you wrote:
> On Thu, Apr 19, 2007 at 10:28:46AM +0200, Stein M. Hugubakken wrote:
> > Hi!
> >
> > I have a lot of free inodes on my xfs-partitions and was wondering
> > about what impact this has on performance or memory?
>
> None.  The number of free inodes is a made up number. ;)

That's for normal usage.
Well, David don't forget what you tell me some time ago about
xfs_repair


  In terms of inode count, I generally use the rule that for every
  10million inodes you need a gigabyte of RAM for repair - you needed
  about 500MB for 6million inodes.


The inode count also affects xfsdump/xfsrestore operations but I don't
know the details. There was a huge improvement in performances for
partial dump with xfsprogs-2.8.16 IIRC.

Regards,
Daniele P.

Re: Inode usage

[Daniele P.]

On Thursday 19 April 2007 15:42, you wrote:
> On Thursday 19 April 2007 15:14, you wrote:
> > On Thu, Apr 19, 2007 at 10:28:46AM +0200, Stein M. Hugubakken wrote:
> > > Hi!
> > >
> > > I have a lot of free inodes on my xfs-partitions and was
> > > wondering about what impact this has on performance or memory?
> >
> > None.  The number of free inodes is a made up number. ;)

Sorry. I was really blind. I didn't read "free".

Apologies,
Daniele P.