On Monday February 20, mirko.benz@xxxxxx wrote: > Hello, > > We have applications were large data sets (e.g. 100 MB) are sequentially > written. > Software RAID could do a full stripe update (without reading/using > existing data). > Does this happen in parallel? If yes, isn't that data vulnerable when a > crash occurs? md/raid5 does full stripe writes about 80% of the time when I've measured it while doing large writes. I'm don't know why it is not closer to 100%. I suspect some subtle scheduling issue that I haven't managed to get to the bottom of yet (I should get back to that). Data is only vulnerable if, after the crash, the array is degraded. If the array is still complete after the crash, then there is no loss of data. NeilBrown - 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