как синхронизировать mdraid

Подскажите плз, имеется 2 винта sda sdb. Sdb сдох - хостер заменил его.
Как теперь синхронизировать?

kref:~# cat /proc/mdstat
Personalities : [raid0] [raid1] [raid6] [raid5] [raid4] [raid10]
md2 : active raid1 sda3[0]
726266432 blocks [2/1] [U_]

md1 : active raid1 sda2[0]
2104448 blocks [2/1] [U_]

md0 : active raid1 sda1[0]
4200896 blocks [2/1] [U_]

kref:~# fdisk -l

Disk /dev/sda: 750.1 GB, 750156374016 bytes
255 heads, 63 sectors/track, 91201 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x00062ddc

Device Boot Start End Blocks Id System
/dev/sda1 1 523 4200966 fd Linux raid autodetect
/dev/sda2 524 785 2104515 fd Linux raid autodetect
/dev/sda3 786 91201 726266520 fd Linux raid autodetect

Disk /dev/sdb: 750.1 GB, 750156374016 bytes
255 heads, 63 sectors/track, 91201 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x55555555

Disk /dev/sdb doesn't contain a valid partition table

Disk /dev/md0: 4301 MB, 4301717504 bytes
2 heads, 4 sectors/track, 1050224 cylinders
Units = cylinders of 8 * 512 = 4096 bytes
Disk identifier: 0x00000000

Disk /dev/md0 doesn't contain a valid partition table

Disk /dev/md1: 2154 MB, 2154954752 bytes
2 heads, 4 sectors/track, 526112 cylinders
Units = cylinders of 8 * 512 = 4096 bytes
Disk identifier: 0x00000000

Disk /dev/md1 doesn't contain a valid partition table

Disk /dev/md2: 743.6 GB, 743696826368 bytes
2 heads, 4 sectors/track, 181566608 cylinders
Units = cylinders of 8 * 512 = 4096 bytes
Disk identifier: 0x00000000

Disk /dev/md2 doesn't contain a valid partition table