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? >
See this, posted 2 years ago to freebsd-fs: http://freebsd.monkey.org/freebsd-fs/200610/msg00024.html Scott Long says the bug in vfs_bio.c is known but difficult to fix. They also argued that using a 64KiB blocksize should not be necessary. I have been getting slightly higher scores with 64KiB blocksize though, also with perfect alignment. 32KiB should be safe to use, i have not managed to crash the system under heavy I/O load. I'm curious if my suggestions gave you any better results, though. Regards, Veronica _______________________________________________ [email protected] mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-hardware To unsubscribe, send any mail to "[EMAIL PROTECTED]"
