[ak217]

I don't know what caused your experience, but I've had the opposite experience using XFS with many small files. It's my filesystem of choice for simple (single device) use cases.

The main reason is that XFS automatically allocates inode space. With ext4, I would quickly run out of the default inode quota while the volume was nowhere near full, and then manually tune the inode to block ratio to accommodate more files. XFS took care of that automatically. Performance was otherwise identical, and I've never seen any data loss bugs or even crashes from either one.

[GuestFAUniverse]

How many decades ago was that? Sounds more like a partition converted from ext3. No ext4 partition I've seen in the last 15y, didn't have a ridiculous amount of inodes. I do support for several hundred Linux systems.

[ak217]

Zero decades ago? I run EC2 instances that process hundreds of millions of small files. I always use the latest Ubuntu LTS.

I'm also tired of trying to share my experience and having to choose between ignoring snide ignorant low-brow dismissals, and leaving them unanswered so they can misinform people. Ext4 does not have a dynamic inode reservation adjustment feature. XFS does. So with ext4, it's possible to run out of inodes while there are blocks available. With XFS, it's not.

[starspangled]

From this paper https://arxiv.org/html/2408.01805v1 (2024)

> EXT4 is the general-purpose filesystem for a majority of Linux distributions and gets installed as the default. However, it is unable to accommodate one billion files by default due to a small number of inodes available, typically set at 240 million files or folders, created during installation.

Which is interesting. I knew EXT2/3/4 had inode bitmaps, but I haven't been paying them much attention for the past decade. Slightly surprised they haven't added an option for dynamic allocation, OTOH inodes are small compared with storage and most people don't need billions of files.

[Dylan16807]

That person is being extremely silly when they call that "small".

Ext2/3/4 reserves so many inodes by default. One per 16KB of drive space. You don't hit that with normal use. Almost everyone should be reducing their inode count so it doesn't take up 1.6% of the drive.

[starspangled]

> That person is being extremely silly when they call that "small".

Explain.

> Ext2/3/4 reserves so many inodes by default. One per 16KB of drive space. You don't hit that with normal use. Almost everyone should be reducing their inode count so it doesn't take up 1.6% of the drive.

Well almost, but not the OP who runs out of inode space with the default format.

[Dylan16807]

> Explain.

Hundreds of millions of inodes is not a small number. I'm not sure how I can explain that much better. There are multiple orders of magnitude between "240 million inodes" and "a small number of inodes".

And on a 14TB hard drive, the default would be more like 850 million.

> Well almost, but not the OP who runs out of inode space with the default format.

I said "almost" for a reason. It's a bad idea for quite small drives or some rare use cases.

[starspangled]

> Hundreds of millions of inodes is not a small number. I'm not sure how I can explain that much better. There are multiple orders of magnitude between "240 million inodes" and "a small number of inodes".

The poster with the inode problem in the subthread I replied to said "many small files" and "millions of small files", not "a small number of inodes".

> I said "almost" for a reason. It's a bad idea for quite small drives or some rare use cases.

Though source trees often are smaller than 16kB/inode, so the advice to decrease inode allocation just to save a fraction of 1.6% of space may not be too good. I would leave it as default unless there is good reason to change. And that's of course the trouble with fixed inode allocation.

[raudette]

I ran a very small personal webserver with limited storage on Ubuntu on EC2 for a while.

The EC2 instance, likely the smallest configuration available at the time, hit an inode limit just running updates over time.

[Dylan16807]

Super small drives are a special case for sure. You don't want to go below a certain number of inodes even on a 5GB root, but you also don't want to scale that up 50x on a 250GB root.

[throwdbaaway]

With gentoo, if you allocate let's say 20G to / on ext4, then you can quite easily run into this issue.

/usr/src/linux will use about 30% of the space and 10% of the inodes.

/var/db/repos/gentoo will use about 4% of the space and 10% of the inodes.

Next you clone the firefox-source hg repo, which will use about 15% of the space and 80% of the inodes.

[Dylan16807]

> Next you clone the firefox-source hg repo, which will use about 15% of the space and 80% of the inodes.

Looking at my mozilla checkout the source and repo average 6KB per file, which would eat lots of inodes.

But once I compile it, it's more like 20KB per file, which is just fine on default settings. So I'm not sure if the inodes are actually the limiting factor in this scenario?

And now that they're moving to git, the file count will be about 70% smaller for the same amount of data.

[Dylan16807]

Based on the mke2fs git history, the default has been a 256 byte inode per 16KB of drive size since 2008, and a 128 byte inode per 8KB of drive size before that.

[nicman23]

i had ext4 telling out of space with 52% in df lol

i just converted it inline to btrfs