On Tue, 5 Feb 2013, Tvrtko Ursulin wrote: > Date: Tue, 05 Feb 2013 14:30:24 +0000 > From: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxx> > To: Lukáš Czerner <lczerner@xxxxxxxxxx> > Cc: Prashant Shah <pshah.mumbai@xxxxxxxxx>, linux-ext4@xxxxxxxxxxxxxxx > Subject: Re: Maximum number of directories > > > Hi, > > On Tuesday 05 February 2013 14:06:14 Lukáš Czerner wrote: > > On Mon, 4 Feb 2013, Tvrtko Ursulin wrote: > > > Date: Mon, 04 Feb 2013 13:36:29 +0000 > > > From: Tvrtko Ursulin <tvrtko.ursulin@xxxxxxxxxxxx> > > > To: Prashant Shah <pshah.mumbai@xxxxxxxxx> > > > Cc: linux-ext4@xxxxxxxxxxxxxxx > > > Subject: Re: Maximum number of directories > > > > > > On Monday 04 February 2013 18:49:54 Prashant Shah wrote: > > > > Hi, > > > > > > > > On Mon, Feb 4, 2013 at 4:25 PM, Tvrtko Ursulin > > > > > > > > <tvrtko.ursulin@xxxxxxxxxxxx> wrote: > > > > > I was creating such a (crazy?) tree and hit -ENOSPC at ~31 million > > > > > directories created in total with df showing only 40% use: > > > > > > > > > > Inode count: 29868032 > > > > > Free inodes: 29848131 > > > > > > > > Since, each directory will use a inode entry, there is some mismatch > > > > with ~31 million directories and 19901 inodes in use. The inode usage > > > > count should be much larger. You have max 29 million inodes available > > > > - so max can be 29 million directories. > > > > > > Yeah, I totally forgot about the inode situation on ext filesystems. So is > > > tune2fs giving wrong stats for live (mounted) filesystems? > > > > Not sure what situation you're referring to. Directory as any other > > file is represented by an inode and there is a limited number of > > inodes in the file system. > > The situation that inode blocks are statically allocated at mkfs time. Yes, that is true. > > > Using tune2fs on live/mounted file system is bad idea and the > > information might not be correct (exactly for this reason it is > > _NOT_ recommended to run fsck on live file system). Use 'df -i' if > > you want to get information about inode count. > > Yes, later I figured out that tune2fs -l does not give current stats for live > filesystems. I did not expect that to be dangerous though. And I also forgot > about 'df -i'. Thing is, I did not hit this limit since the previous century > so guess I subconsciously assumed inode limits are an outdated concept. :) Running tune2fs -l on live file system is not dangerous, I did not said that. Running fsck on live file system on the other hand _is_ dangerous. -Lukas > > Regards, > > Tvrtko > >
