http://bugzilla.novell.com/show_bug.cgi?id=590650 http://bugzilla.novell.com/show_bug.cgi?id=590650#c0 Summary: md: raid1 with 1/2 disks and bitmap is VERY SLOW Classification: openSUSE Product: openSUSE 11.2 Version: Final Platform: Other OS/Version: Other Status: NEW Severity: Normal Priority: P5 - None Component: Kernel AssignedTo: kernel-maintainers@forge.provo.novell.com ReportedBy: jnelson-suse@jamponi.net QAContact: qa@suse.de Found By: --- Blocker: --- User-Agent: Mozilla/5.0 (X11; U; Linux x86_64; en-US; rv:1.9.1.8) Gecko/20100204 SUSE/3.5.8-0.1.1 Firefox/3.5.8 I created a raid1 with 1 physical disk and 1 missing disk. chunksize = 256 With bitmap=internal, the array does 5-11MB/s writes. With bitmap=none, the array does (in excess of) 60MB/s writes. Why should that be? With only 1 drive, why is the bitmap being updated at all? Aren't *all* of the bits in the bitmap already set? Therefore, why does I/O have to be performed to check the bitmap? IMO, perhaps if the bitmap is not changing or does not require change, then it should not require I/O - in this case there appears to be an optimization that could be applied. Reproducible: Always Steps to Reproduce: 1. 2. 3. -- Configure bugmail: http://bugzilla.novell.com/userprefs.cgi?tab=email ------- You are receiving this mail because: ------- You are on the CC list for the bug.