[Lustre-discuss] explanation about inodes in MDT/OST

Parinay Kondekar parinay_kondekar at xyratex.com
Wed Jun 19 07:23:26 PDT 2013

*IMO* there are two limiting factors

1. total number of inodes supported by MDT and
2.  OSTs  i.e. num_ost_inodes = 4 * number_of_mds_inodes *
default_stripe_count / *number_of_osts*

so your Q
I am not sure I understand this 100%, when adding an OST I do or don't
gain inodes?or you basically only get more inodes in the data part of
the filesystem but if you don't have enough inodes on the MDT you
still have a problem?
Yes, if there are no enough inodes on MDT adding OSTs wont help much.

I don't think you can change no. of inodes w/o formatting. You might want
to take a look at
lfs_migrate, on how to increase the no_of_inodes on OST's.


On 19 June 2013 19:19, E.S. Rosenberg <esr+lustre at mail.hebrew.edu> wrote:

> "
> In a Lustre ldiskfs file system, all the inodes are allocated on the
> MDT and OSTs when the file system is first formatted. The total number
> of inodes on a formatted MDT or OST cannot be easily changed, although
> it is possible to add OSTs with additional space and corresponding
> inodes. Thus, the number of inodes created at format time should be
> generous enough to anticipate future expansion.
> "
> http://build.whamcloud.com/job/lustre-manual/lastSuccessfulBuild/artifact/lustre_manual.xhtml#understandinglustre.fig.cluster
> Also if lustrefs is really based on ext4 doesn't ext4 support growing
> the amount of inodes with resize2fs?
> Thanks,
> Eli
> _______________________________________________
> Lustre-discuss mailing list
> Lustre-discuss at lists.lustre.org
> http://lists.lustre.org/mailman/listinfo/lustre-discuss
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.lustre.org/pipermail/lustre-discuss-lustre.org/attachments/20130619/8f34c9a3/attachment.htm>

More information about the lustre-discuss mailing list