Neil Brown wrote: > On Sunday March 4, pernegger@xxxxxxxxx wrote: >>I have a mismatch_cnt of 384 on a 2-way mirror. [trim] >>3) Is the "repair" sync action safe to use on the above kernel? Any >>other methods / additional steps for fixing this? > > "repair" is safe, though it may not be effective. > "repair" for raid1 was did not work until Jan 26th this year. > Before then it was identical in effect to 'check'. How is "repair" safe but not effective? When it finds a mismatch, how does it know which part is correct and which should be fixed (which copy of raid1, or which block in raid5)? When a disk fails we know what to rewrite, but when we discover a mismatch we do not have this knowledge. It may corrupt the good copy of a raid1. -- Eyal Lebedinsky (eyal@xxxxxxxxxxxxxx) <http://samba.org/eyal/> - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
