Re: high load, no bottleneck

[christos%zoulas.com@localhost (Christos Zoulas)]

On Sep 19,  8:13am, tls%panix.com@localhost (Thor Lancelot Simon) wrote:
-- Subject: Re: high load, no bottleneck

| On Wed, Sep 18, 2013 at 06:03:11PM +0200, Emmanuel Dreyfus wrote:
| > Emmanuel Dreyfus <manu%netbsd.org@localhost> wrote:
| > 
| > > Thank you for saving my day. But now what happens?
| > > I note the SATA disks are in IDE emulation mode, and not AHCI. This is
| > > something I need to try changing:
| > 
| > Switched to AHCI. Here is below how hard disks are discovered (the relevant 
raid
| > is RAID1 on wd0 and wd1)
| > 
| > In this setup, vfs.wapbl.flush_disk_cache=1 still get high loads, on both 
6.0
| > and -current. I assume there must be something bad with WAPBL/RAIDframe
| 
| There is at least one thing: RAIDframe doesn't allow enough simultaneously
| pending transactions, so everything *really* backs up behind the cache flush.
| 
| Fixing that would require allowing RAIDframe to eat more RAM.  Last time I
| proposed that, I got a rather negative response here.

sysctl to the rescue.

christos