Doesn't filesystem use inodes that got free?

Mr. Alex · 09-05-2012, 07:29 AM

Hi all!
http://www.linux-mag.com/id/8658/

Quote:

How inodes are created and even if they are created, depends upon the specific file system. Several file systems create all of them when the file system is created resulting in a fixed number of inodes. For example, ext3 is a file system that does this. The result is that the file system has a fixed number of files that can be stored. Yes – it’s actually possible to have capacity on the storage and not be able to store any more data (it doesn’t happen often but it’s theoretically possible). If you need more inodes you have to remake the file system losing all data in the file system.

So when inodes get free because their files are deleted - filesystem doesn't use those inodes?

pan64 · 09-05-2012, 07:32 AM

the free inodes will be reused, but the total number of inodes in a filesystem cannot be changed (so part of them used, the others are free).

sundialsvcs · 09-05-2012, 08:30 AM

But also note that Logical Volume Manager (LVM) software provides an effective alternative, as do Storage Area Networks (SANs) on a much larger hardware-implemented scale.

Under these systems, the physical volume boundaries are blurred into irrelevance. Files continue to be data-objects which are referenced by name and possibly also by a binary token-value (e.g. an "inode number"), but these no longer map directly to where the data is. When a physical volume fills up, you simply add another one to the pool.

Mr. Alex · 09-05-2012, 10:03 AM

Quote:

Originally Posted by pan64

the free inodes will be reused, but the total number of inodes in a filesystem cannot be changed (so part of them used, the others are free).

OK, so the article made it pretty unclear. Got it now.
Have anyone here ever run out of inodes? Just curious...

pan64 · 09-05-2012, 11:38 AM

yes, it can happen, just create a huge amount of small files ("usually" some app make such logfiles)