How to create filesystem with lower reserve space

[James R. Ferguson]

Hi (again):

I think what you are seeing it the difference in the average file sizes in each of the two filesystems.

If you look at the values for 'f_blocks' and 'f_files' given the same value for 'f_bsize' you will see that for the first filesystem each node (file) consumes about 4 blocks on average. For the second filesystem, each node consumes about 100 blocks.

A file whose actual size is _less_ than 8K (8192) still has to use the lowest unit of space --- the 'f_bsize'. Hence for the first filesystem I would expect a higher proportion of wasted space.

The block size is set during creation and ultimately governs how large the overall filesystem can be:

http://www.docs.hp.com/en/B2355-60105/mkfs_vxfs.1M.html

Regards!

...JRF...

[OldSchool]

I think that, by "reserve space", hes referring to the space root could get to in the event you got a "disk full" error....

as in somebody fills / or whatever causing logins to stop. root can usually get in because the default was to leave 10% available (which might include space for the inode tables for all I know).

i didn't realize that was "tunable" however

[Patrick Wallek]

OS -- I agree with what you say about the min free space.

>>i didn't realize that was "tunable" however

It is on HFS file systems. The '-m' parameter to newfs / mkfs tunes that. It's not tunable on VxFS though.

[Steven E. Protter]

Shalom,

I would suggest backing up the data and running newfs again is the only route available to you.

Since fsadm can not tune it, that appears to be the only way to go.

I might first though look to see if lowering the reserve space to that low a level might not cause performance impact as the filesystem gets closer to full status.

SEP