How to store one billion files on ext4?
I only created about 8 million files, then there was no free inode in /dev/sdb1.
[spider@localhost images]$ df -i
Filesystem Inodes IUsed IFree IUse% Mounted on
/dev/sdb1 8483456 8483456 0 100% /home
Someone says can specify the inode count when format the partition.
e.g. mkfs.ext4 -N 1000000000.
I tried but got an error:
"inode_size (256) * inodes_count (1000000000) too big...specify higher inode_ratio (-i) or lower inode count (-N). ".
What's the appropriate inode_ratio value?
I heard the min inode_ratio value is 1024 for ext4.
Is it possible to store one billion files on a single partition? How to? And someone says it will be very slow.
Answer
When creating an ext4 file system, you can specify the usage type:
mkfs.ext4 -T usage-type /dev/something
The available usage types are listed in /etc/mke2fs.conf. The main difference between usage types is the inode ratio. The lower the inode ratio, the more you can create files in your file system.
The usage type in mke2fs.conf which allocates the highest number of inodes in the file system is "news". With this usage type on a 1 TB hard drive, ext4 creates 244 million inodes.
# tune2fs -l /dev/sdb1 | grep -i "inode count"
Inode count: 244219904
# sgdisk --print /dev/sdb
Disk /dev/sdb: 1953525168 sectors, 931.5 GiB
This means that it would require more than 4 TB to create an ext4 file system with "-Tnews" that could possibly hold 1 billion inodes.