2017-06-01 22:26 GMT+03:00 Marat Khalili <mkh@xxxxxx>: >>raid 1 write data on all disks synchronously all time, no tricks. >>btrfs raid1 read data by PID%2 >>0 - first copy >>1 - second copy > > Meaning, a single-process database will only ever read one copy? At least, meaning of first/second relative to physical devices depends on extent, right, right? > -- > > With Best Regards, > Marat Khalili > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html IIRC, https://github.com/torvalds/linux/blob/dc9edaab90de9441cc28ac570b23b0d2bdba7879/fs/btrfs/volumes.c#L5764 So, for single process database you will read only from one disk. -- Have a nice day, Timofey. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
