[Gluster-users] Arbiter brick size estimation

[Oleksandr Natalenko]

Hi.

On вівторок, 8 березня 2016 р. 19:13:05 EET Ravishankar N wrote:
> I think the first one is right because you still haven't used up all the
> inodes.(2036637 used vs. the max. permissible 3139091). But again this
> is an approximation because not all files would be 899 bytes. For
> example if there are a thousand files present in a directory, then du
> <dirname> would be more than du <file> because the directory will take
> some disk space to store the dentries.

I believe you've got me wrong. 2036637 is the number of files+folders. 3139091 
is the amount of inodes actually allocated on the underlying FS (according to 
df -i information). The max. inodes number is much higher than that, and I do 
not take it into account.

Also, probably, I should recheck the results for 1000 files per folder to make 
it sure.

> The 4KB is a conservative estimate considering the fact that though the
> arbiter brick does not store data, it still keeps a copy of both user
> and gluster xattrs. For example, if the application sets a lot of
> xattrs, it can consume a data block if they cannot be accommodated on
> the inode itself.  Also there is the .glusterfs folder like you said
> which would take up some space. Here is what I tried on an XFS brick:

4KB as upper level sounds and looks reasonable to me, thanks. But the average 
value will be still lower, I believe, as it is uncommon for apps to set lots 
of xattrs, especially for ordinary deployment.

Regards,
  Oleksandr.