Are large RAID stripe sizes useful with FreeBSD?

Xin LI delphij at
Mon Mar 31 11:55:53 PDT 2008

Ivan Voras wrote:
> Most of new hardware RAID controllers offer stripe sizes of 128K, 256K
> and some also have 512K and 1M stripes. In the simplest case of RAID0 of
> two drives, knowing that the data is striped across the drives and that
> FreeBSD issues IO request of at most 64K, is it useful to set stripe
> sizes to anything larger than 32K? I suppose something like TCQ would
> help the situation but does anyone know how is this situation usually
> handled on the RAID controllers?

Short answer: yes.  Larger stripe sizes would allow better performance 
for continuous read/write.  In theory they will negatively affect small 
size read/write but in practice you will notice that larger stripe size 
would give better performance in almost all cases.

Xin LI <delphij at>
FreeBSD - The Power to Serve!

More information about the freebsd-current mailing list