What is the default limit on an unraid array for inodes (or for files and directories)?  I was reading about  this at http://www.linfo.org/inode.html 

 

Does unraid allocate inodes space at roughly one inode per 2kB of HDD?  If yes, then does it follow that a 20TB array can have about 10 billion inodes?  

 

Currently my Roon appdata  is only 21 GB, but uses 91k files and 47k directories. That is about 130kB per inode.  The music itself is about 3TB using 272k files and 76k directores.  that is about 20MB per inode.   I guess there is no concern about running out of inodes?

 

What are inodes?...

I like this explanation of inodes http://www.linfo.org/inode.html

 

From it, i learned how to do my first command line and got this, today, and I can see I have used 1%, or less, of my inodes.

root@Tower:~# df -hi
Filesystem     Inodes IUsed IFree IUse% Mounted on
rootfs           2.0M   12K  2.0M    1% /
devtmpfs         2.0M   492  2.0M    1% /dev
tmpfs            2.0M     3  2.0M    1% /dev/shm
cgroup_root      2.0M    13  2.0M    1% /sys/fs/cgroup
tmpfs            2.0M    67  2.0M    1% /var/log
/dev/sda1           0     0     0     - /boot
overlay          2.0M   12K  2.0M    1% /lib/modules
overlay          2.0M   12K  2.0M    1% /lib/firmware
tmpfs            2.0M     1  2.0M    1% /mnt/disks
tmpfs            2.0M     1  2.0M    1% /mnt/remotes
/dev/md1         746M  409K  745M    1% /mnt/disk1
/dev/md2         466M   87K  466M    1% /mnt/disk2
/dev/md3         746M   12K  746M    1% /mnt/disk3
/dev/md4         746M  522K  745M    1% /mnt/disk4
/dev/md5         746M  443K  745M    1% /mnt/disk5
/dev/nvme0n1p1      0     0     0     - /mnt/cache
shfs             3.4G  1.5M  3.4G    1% /mnt/user0
shfs             3.4G  1.5M  3.4G    1% /mnt/user
/dev/loop2          0     0     0     - /var/lib/docker
root@Tower:~# ^C
root@Tower:~# 

 

Edited June 13, 20215 yr by xrqp

If your appdata is on the cache and the cache pool is btrfs formatted then you don't need to worry about running out of inodes anyway because the number isn't fixed, which is why the percentage used is meaningless and shows as zeros in the output of df -i.

 

My cache is btrfs, but my array is xfs.  I think the number of inodes is fixed for xfs, so I was interested if Roon, using so many small files would have a problem.  But the more I researched it, the less I was concerned, and now I have no concern at all.

 

Now that you mention cache using btrfs should show zero inodes, I am glad you explained it, and that it can self adjust as needed.