xfs tuning for a 830 GB partition (mkfs.xfs options)

[Abel Coto <whitewolf573@xxxxxxxxx>]

I want to create a 830 GB partition, to mount as /home in my Centos 5.4 workstation. 

Actually i have /home not mounted ,so i would have to create the new partition in the lvm,format it and use rsync to copy /home directory to it.

for a 830 GB partition that i will use to save my data in general and also 3d / CG projects and renders once finished them what agcount value should be used. I have read that mkfs default option creates 1 allocation group each 4G , so i understand that for a 830 GB partition agcount should be 208.

It is this correct ? 

so i would use for format the partition 

mkfs.xfs -l lazy-count=1,version=2,size=128m -i attr=2 -d agcount=208 -L VolumeName <dev>

I have read that some people instead use a 8GB allocation size , and agcount Size partition / 8 GB (in my case 104) , but i don't know if that would be good , as would result in less allocation groups. 

i understand if agcount > 208  (for example 416 ) , the allocation size (2GB for agcount=416) would be less than 4 GB , to have in total 830 GB.

I have read that too much allocation groups are bad , but i don't now if 416 are  too much for a 830 GB partition (and shoukd use 208 to 300) or not.

I will mount the partition with logbufs=8. (i use a 128m journal and logbufs=8 to improve a bit deleting performance). I will perhaps use noatime too ,but i have to see if my backup app, uses atime or not.


I have another 1,5 TB HDD where i want to create a 350 GB xfs partition to save the 3d projects and render output when working with the 3d software i use (Maya 2011). My thoughts are to use /home to save both music , photography,isos,etc also of finished 3d / cg work and iso dvd / tutorials and video-tutorials ,and this 350 GB partition use it only for data and projects that i am still working with,and once finished copy to /home.

for this partition , that will handle mostly big files (500 MB to 2-3 GB at least) what mkfs.xfs options should i use ?

something like:

mkfs.xfs -l lazy-count=1,version=2,size=128m -i attr=2 -d agcount=90 -L VolumeName <dev>  (350/4 --> 88)

I prefer to have a separate partition to save projects at least when i am working with them , although 3d modelling is not too much filesystem bounded , and then copy it to /home , as i think having a good backup strategy shoud not be a problem to have my music and data along with 3d work finished in the same partition (3d is for me a hobby,that i like a lot but a hobby)

I will have to compile a custom kernel from kernel.org because my centos kernel is 2.6.18,and there is no higher one available, only compiling it, but this shouldn't be a problem.