我正在 PXE 启动并自动安装 20.04 服务器，但没有成功。该服务器正在user-data从我的 cloud-init 服务器获取文件，但在每次安装时都会失败，convert_autoinstall_config: max() arg is an empty sequence
作为参考我的 ipxe 参数：
kernel vmlinuz root=/dev/ram0 ip=dhcp hostname=test url=http://releases.ubuntu.com/20.04.2/ubuntu-20.04.2-live-server-amd64.iso autoinstall ds=nocloud-net;s=http://server/configs/
initrd initrd
更令人兴奋的是我的用户数据（来自 Canonical 的简单示例，用于测试）
version: 1
identity:
hostname: test
username: tester
password: an_encrypted_password
安装程序错误：
2021-08-05 13:03:52,379 DEBUG root:39 start: subiquity/Filesystem/apply_autoinstall_config/convert_autoinstall_config:
2021-08-05 13:03:52,379 DEBUG subiquity.server.controller.filesystem:193 self.ai_data = {'layout': {'match': {'path': '/dev/sda'}, 'name': 'lvm'}}
2021-08-05 13:03:52,379 DEBUG subiquity.common.filesystem:369 bootloader Bootloader.BIOS
2021-08-05 13:03:52,381 ERROR root:39 finish: subiquity/Filesystem/apply_autoinstall_config/convert_autoinstall_config: FAIL: max() arg is an empty sequence
2021-08-05 13:03:52,382 ERROR root:39 finish: subiquity/Filesystem/apply_autoinstall_config: FAIL: max() arg is an empty sequence
2021-08-05 13:03:52,382 ERROR root:39 finish: subiquity/apply_autoinstall_config: FAIL: max() arg is an empty sequence
2021-08-05 13:03:52,382 ERROR subiquity.server.server:261 top level error
Traceback (most recent call last):
File "/snap/subiquity/2280/lib/python3.6/site-packages/subiquity/server/server.py", line 365, in start
await self.apply_autoinstall_config()
File "/snap/subiquity/2280/lib/python3.6/site-packages/subiquitycore/context.py", line 148, in decorated_async
return await meth(self, **kw)
File "/snap/subiquity/2280/lib/python3.6/site-packages/subiquity/server/server.py", line 310, in apply_autoinstall_config
await controller.apply_autoinstall_config()
File "/snap/subiquity/2280/lib/python3.6/site-packages/subiquitycore/context.py", line 148, in decorated_async
return await meth(self, **kw)
File "/snap/subiquity/2280/lib/python3.6/site-packages/subiquity/server/controllers/filesystem.py", line 103, in apply_autoinstall_config
self.convert_autoinstall_config(context=context)
File "/snap/subiquity/2280/lib/python3.6/site-packages/subiquitycore/context.py", line 142, in decorated_sync
return meth(self, **kw)
File "/snap/subiquity/2280/lib/python3.6/site-packages/subiquity/server/controllers/filesystem.py", line 200, in convert_autoinstall_config
meth(disk)
File "/snap/subiquity/2280/lib/python3.6/site-packages/subiquity/common/filesystem.py", line 389, in guided_lvm
self.add_boot_disk(disk)
File "/snap/subiquity/2280/lib/python3.6/site-packages/subiquity/common/filesystem.py", line 372, in add_boot_disk
new_boot_disk.partitions(), key=lambda p: p.size)
ValueError: max() arg is an empty sequence
