Inodes are calculated, the number of inodes you are left with depend on:
- Partition size,
- bytes/inode ratio.
Beside the partition size, most of the time you do not alter blocksize and b/i ration. Changing these can be a good idea if you already know if files written to this partition are small/big.
I.e. lots of files with a small size (say 2k) and a 'large' blocksize (say 8k) will have a 'negative' result because for every file written (2k) a size of 8K (blocksize) is allocated on disk. You cannot access the 6K that's 'empty'.
Take a look at the manpage for mke2fs for available options.
The number of inodes do not degrade the performance. If partitons are very large there could be a sligth decrease in performance due to the 'travel' the head(s) needs to do.
Besides inodes, there are a lot more things you need to think of when tuning a box. Here are just 2:
- Can hardware do simultanious reads/writes (ide/scsi/controller),
- I/O intens or CPU intens,
Some links that could be of interrest:
Hope this helps.