How to create a grub bootloader if the disks are in raid1?

Question

linux

Hello, there are 2 physical disks in the software raid1. A swap is created equal to 2gb and a root equal to 18gb (all remaining space) At the moment, if you remove sda ​​from the system, then linux will not boot naturally. No?
Disk /dev/sda: 20 GiB, 21474836480 bytes, 41943040 sectors
Disk model: VMware Virtual S
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/ optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: D3B557C2-171C-498C-8F77-6FA95E385CDD

Device Start End Sectors Size Type
/dev/sda1 2048 4095 2048 1M BIOS boot
/dev/sda2 4096 4198399 4194304 2G Linux filesystem
/dev/sda3 4198400 41940991 37742592 18G Linux filesystem

Disk /dev/sdb: 20 GiB, 21474836480 bytes, 41943040
Disk model: VMware sectors by
1 * 5 sectors :2 of2 sectors
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: A22BE352-530A-41CB-8784-A2D490B9C997

Device Start End Sectors Size Type
/dev/sdb1 2048 4196351 4194304 2G Linux filesystem
/dev/sdb2 4196352 41940991 37744640 18G Linux filesystem

Disk /dev/md0: 1,102 GiB, 2144337920 bytes, 4188160 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: 439186F9-3320-4A1A -BF6F-415B9CC908AB

Device Start End Sectors Size Type
/dev/md0p1 2048 4182015 4179968 2G Linux swap

Disk /dev/md1: 17.10 GiB, 19306381312 bytes, 37707776 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical /physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: gpt
Disk identifier: 8DB55A61-47B4-403B-920C-1E49693C23E3

Device Start End Sectors Size Type
/dev/md1p1 2048 37701631 37699584 18G Linux filesystem

Answer 1

Well, as an option, since the disks are virtual, remove sdb from the system, add a blank disk to the ride array and wait for synchronization.
Do not forget to set the “bootable” flag on the new disk.
Either stupidly put in a new disk, do dd from the first disk ... and set it the same way flag and add to raid

Answer 2

What did you combine into a RAID array - physical disks or partitions on disks? There are many options...