Test: HighPoint RocketRaid 3120 PCIex1 2xSATA controller under FreeBSD 7.1-PRERELEASE

[Jeremy Chadwick]

On Thu, Sep 18, 2008 at 10:48:03PM +0100, Dieter wrote:
> > If you get about the same scores with dd, try using a higher read-ahead
> > (vfs.read_max value, set it to 32 for example). Also sometimes it's
> > required to use a higher blocksize to get full potential, try:
> > 
> > newfs -U -b 32768 /dev/<raid device>
> > 
> > Warning: using 64KiB blocksize you risk hanging the system under heavy
> > load (like 2 bonnies running simultaniously).
> 
> What's this about 64KiB blocksize hanging the system?
> Hang awhile then recover, or hang forever need a reboot?
> Is this a RAID thing or are normal disks at risk?
> It isn't obvious why a 64KiB blocksize would cause a
> problem in this day of multi GiB memory.

Why do you think the amount of memory people have in their computers has
*anything* to do with a filesystem blocksize?  If a large blocksize
would crash a filesystem, it's not going to be due to "not having enough
RAM".

-- 
| Jeremy Chadwick                                jdc at parodius.com |
| Parodius Networking                       http://www.parodius.com/ |
| UNIX Systems Administrator                  Mountain View, CA, USA |
| Making life hard for others since 1977.              PGP: 4BD6C0CB |