这个问题已被问过无数次，并有无数个答案，但我找不到一个可以解决我的问题。
我只安装了一个操作系统：Ubuntu 16.04 32 位。我想将其更改为 Ubuntu 16.04 64 位。当我尝试安装时，安装程序未检测到操作系统并建议擦除整个磁盘，这不是我想要的。
我尝试运行 fixparts 并重写了分区表。但这并没有改变问题。
我已经尝试了 UEFI 和 BIOS 模式。
我以前安装时也遇到过这种情况，不得不“做点别的”并手动分配根分区。但我总是觉得这很麻烦。如果 Ubuntu 能建议采取适当的措施，用新安装替换 32 位启动分区 (sda1)，我会非常高兴。
也许下一步是运行 ubiquity 的调试模式，看看是否能找到线索。否则，我将不得不进一步挖掘，从 /usr/lib/ubiquity/plugins/ubi-partman.py 中的“def calculate_operating_systems”开始。
# lsb_release -a
Distributor ID: Ubuntu
Description: Ubuntu 16.04.1 LTS
Release: 16.04
Codename: xenial
# sudo fdisk -l
Disk /dev/sda: 1.8 TiB, 2000398934016 bytes, 3907029168 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: dos
Disk identifier: 0x000a2f5d
Device Boot Start End Sectors Size Id Type
/dev/sda1 * 2048 499711 497664 243M 83 Linux
/dev/sda2 501759 312580095 312078337 148.8G f W95 Ext'd (LBA)
/dev/sda3 312580096 3907028991 3594448896 1.7T 83 Linux
/dev/sda5 501760 312580095 312078336 148.8G 8e Linux LVM
Partition table entries are not in disk order.
Disk /dev/mapper/merlot-root: 146 GiB, 156703391744 bytes, 306061312 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
Disk /dev/mapper/merlot-swap_1: 2.9 GiB, 3078619136 bytes, 6012928 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
# sudo dmsetup deps -o devname
merlot-swap_1: 1 dependencies : (sda5)
merlot-root: 1 dependencies : (sda5)
# sudo dmsetup -v table /dev/mapper/merlot-root
Name: merlot-root
State: ACTIVE
Read Ahead: 256
Tables present: LIVE
Open count: 1
Event number: 0
Major, minor: 252, 0
Number of targets: 1
UUID: LVM-nCfFBn74k3QnfrxB0ZX41AxLnua9hTryu96VYKllCnGIJbKdvlPTWshZbejIqeJU
0 306061312 linear 8:5 384
通过删除启动板错误修复 #1265192，我能够让安装程序识别 Ubuntu。这是删除错误修复之前我的系统上的 misc.py 代码和 syslog 输出。
for res in result:
syslog.syslog(res)
res = res.split(':')
# launchpad bug #1265192, fix os-prober Windows EFI path
res[0] = re.match(r'[/\w\d]+', res[0]).group()
if res[2] == 'Ubuntu':
version = [v for v in re.findall('[0-9.]*', res[1]) if v][0]
# Get rid of the superfluous (development version) (11.04)
text = re.sub('\s*\(.*\).*', '', res[1])
_os_prober_oslist[res[0]] = text
_os_prober_osvers[res[0]] = version
syslog.syslog(res[0])
syslog.syslog(text)
syslog.syslog(version)
else:
# Get rid of the bootloader indication. It's not relevant here.
_os_prober_oslist[res[0]] = res[1].replace(' (loader)', '')
return _os_prober_oslist, _os_prober_osvers
May 15 14:44:11 ubuntu os-prober: debug: os detected by /usr/lib/os-probes/50mounted-tests
May 15 14:44:11 ubuntu ubiquity[18280]: /dev/mapper/merlot-root:Ubuntu 16.04.1 LTS (16.04):Ubuntu:linux
May 15 14:44:11 ubuntu ubiquity[18280]: /dev/mapper/merlot
May 15 14:44:11 ubuntu ubiquity[18280]: Ubuntu 16.04.1 LTS
May 15 14:44:11 ubuntu ubiquity[18280]: 16.04.1
May 15 14:44:11 ubuntu ubiquity[18280]: Device /dev/mapper/merlot-swap_1 not found in os-prober output
May 15 14:44:11 ubuntu ubiquity[18280]: Device /dev/sda1 not found in os-prober output
May 15 14:44:11 ubuntu ubiquity[18280]: Device /dev/sda5 not found in os-prober output
May 15 14:44:11 ubuntu ubiquity[18280]: Device /dev/sda3 not found in os-prober output
May 15 14:44:11 ubuntu ubiquity[18280]: Device /dev/mapper/merlot-root not found in os-prober output
May 15 14:44:11 ubuntu ubiquity[18280]: switched to page partman
我不是 Python 程序员，但是
res[0] = re.match(r'[/\w\d]+', res[0]).group()
需要
/dev/mapper/merlot-root
并使其
/dev/mapper/merlot
然后 Ubiquity 就无法找到该驱动器。
唉，一旦我评论了错误修复并选择“替换 ubuntu”选项，安装仍然失败，因此需要做更多的工作来解决这个问题。
我已经在这上面花了足够多的时间，所以我打算做“其他事情”并手动安装。