安装到一半开始无限等待 qcow 文件挂载

**原来的系统：** TencentOS Server 3.1
**安装的系统：** Fedora 42
**服务器配置：** 4 核心 / 16GB 内存 / 100GB 硬盘 / 100Mbps 带宽 / 香港机房
**遇到的问题：**

安装到一半，应该是开始重新调整分区大小的时候，出现了无限等待 qcow 文件挂载的问题（`Waiting for qcow file to be mounted`），我手动登录 ssh 之后输入了以下命令才开始正常安装。

```shell
qemu-nbd --connect=/dev/nbd0 /installer/cloud_image.qcow2
```

查看 `reinstall.log` 的日志内容如下：

展开

```log
WebSocket Connected.
***** START TRANS *****
BOOT_IMAGE=/reinstall-vmlinuz alpine_repo=http://dl-cdn.alpinelinux.org/alpine/v3.22/main modloop=http://dl-cdn.alpinelinux.org/alpine/v3.22/releases/x86_64/netboot/modloop-virt console=ttyS0,115200n8 console=tty0 finalos_distro=fedora finalos_img=https://d2lzkl7pfhq30w.cloudfront.net/pub/fedora/linux/releases/42/Cloud/x86_64/images/Fedora-Cloud-Base-Generic-42-1.1.x86_64.qcow2 finalos_img_type=qemu finalos_releasever=42 extra_confhome=https://raw.githubusercontent.com/bin456789/reinstall/main extra_cloud_image=1 extra_main_disk=8d1a8b0d extra_ssh_port=32768 extra_web_port=10380
fetch http://dl-cdn.alpinelinux.org/alpine/v3.22/community/x86_64/APKINDEX.tar.gz
(1/6) Installing libeconf (0.6.3-r0)
(2/6) Installing libblkid (2.41-r9)
(3/6) Installing libuuid (2.41-r9)
(4/6) Installing libfdisk (2.41-r9)
(5/6) Installing libsmartcols (2.41-r9)
(6/6) Installing sfdisk (2.41-r9)
Executing busybox-1.37.0-r18.trigger
OK: 17 MiB in 45 packages
8d1a8b0d
(1/6) Purging sfdisk (2.41-r9)
(2/6) Purging libfdisk (2.41-r9)
(3/6) Purging libblkid (2.41-r9)
(4/6) Purging libeconf (0.6.3-r0)
(5/6) Purging libsmartcols (2.41-r9)
(6/6) Purging libuuid (2.41-r9)
Executing busybox-1.37.0-r18.trigger
OK: 17 MiB in 39 packages
(1/1) Installing websocketd (0.4.1-r30)
Executing busybox-1.37.0-r18.trigger
OK: 24 MiB in 40 packages
https://raw.githubusercontent.com/bin456789/reinstall/main/logviewer.html
Connecting to raw.githubusercontent.com ([2606:50c0:8001::154]:443)
saving to '/tmp/index.html'
index.html 100% |********************************| 3180 0:00:00 ETA
'/tmp/index.html' saved
(1/8) Installing coreutils-env (9.7-r1)
(2/8) Installing coreutils-fmt (9.7-r1)
(3/8) Installing coreutils-sha512sum (9.7-r1)
(4/8) Installing acl-libs (2.3.2-r1)
(5/8) Installing libattr (2.5.2-r2)
(6/8) Installing skalibs-libs (2.14.4.0-r0)
(7/8) Installing utmps-libs (0.1.3.1-r0)
(8/8) Installing coreutils (9.7-r1)
Executing busybox-1.37.0-r18.trigger
OK: 25 MiB in 48 packages
(1/34) Installing util-linux (2.41-r9)
(2/34) Installing dmesg (2.41-r9)
(3/34) Installing setarch (2.41-r9)
(4/34) Installing libeconf (0.6.3-r0)
(5/34) Installing libblkid (2.41-r9)
(6/34) Installing libuuid (2.41-r9)
(7/34) Installing libfdisk (2.41-r9)
(8/34) Installing libmount (2.41-r9)
(9/34) Installing libsmartcols (2.41-r9)
(10/34) Installing util-linux-misc (2.41-r9)
(11/34) Installing linux-pam (1.7.0-r4)
(12/34) Installing runuser (2.41-r9)
(13/34) Installing mount (2.41-r9)
(14/34) Installing losetup (2.41-r9)
(15/34) Installing hexdump (2.41-r9)
(16/34) Installing uuidgen (2.41-r9)
(17/34) Installing blkid (2.41-r9)
(18/34) Installing sfdisk (2.41-r9)
(19/34) Installing mcookie (2.41-r9)
(20/34) Installing agetty (2.41-r9)
(21/34) Installing agetty-openrc (0.62.5-r0)
(22/34) Installing wipefs (2.41-r9)
(23/34) Installing cfdisk (2.41-r9)
(24/34) Installing umount (2.41-r9)
(25/34) Installing util-linux-openrc (2.41-r9)
(26/34) Installing flock (2.41-r9)
(27/34) Installing lsblk (2.41-r9)
(28/34) Installing libcap-ng (0.8.5-r0)
(29/34) Installing setpriv (2.41-r9)
(30/34) Installing lscpu (2.41-r9)
(31/34) Installing logger (2.41-r9)
(32/34) Installing partx (2.41-r9)
(33/34) Installing fstrim (2.41-r9)
(34/34) Installing findmnt (2.41-r9)
Executing busybox-1.37.0-r18.trigger
OK: 30 MiB in 82 packages
***** CREATE PART *****
(1/6) Installing libcom_err (1.47.2-r2)
(2/6) Installing e2fsprogs-libs (1.47.2-r2)
(3/6) Installing e2fsprogs (1.47.2-r2)
(4/6) Installing device-mapper-libs (2.03.32-r0)
(5/6) Installing readline (8.2.13-r1)
(6/6) Installing parted (3.6-r2)
Executing busybox-1.37.0-r18.trigger
OK: 32 MiB in 88 packages
File size: 507 MiB
Part size need: 657 MiB
mke2fs 1.47.2 (1-Jan-2025)
Creating filesystem with 26045952 4k blocks and 6512640 inodes
Filesystem UUID: d695a41b-e5a0-4415-8b43-d027faf5c0b3
Superblock backups stored on blocks:
32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
4096000, 7962624, 11239424, 20480000, 23887872

Allocating group tables: 0/795 done
Writing inode tables: 0/795 done
Creating journal (131072 blocks): done
Writing superblocks and filesystem accounting information: 0/795 done

mke2fs 1.47.2 (1-Jan-2025)
Creating filesystem with 167936 4k blocks and 42048 inodes
Filesystem UUID: 6b57271f-d030-42bd-95b0-7a0b4b561980
Superblock backups stored on blocks:
32768, 98304, 163840

Allocating group tables: 0/6 done
Writing inode tables: 0/6 done
Creating journal (4096 blocks): done
Writing superblocks and filesystem accounting information: 0/6 done

(1/16) Installing libaio (0.3.113-r2)
(2/16) Installing libffi (3.4.8-r0)
(3/16) Installing libintl (0.24.1-r0)
(4/16) Installing pcre2 (10.43-r1)
(5/16) Installing glib (2.84.3-r0)
(6/16) Installing gmp (6.3.0-r3)
(7/16) Installing nettle (3.10.1-r0)
(8/16) Installing libunistring (1.3-r0)
(9/16) Installing libidn2 (2.3.7-r0)
(10/16) Installing libtasn1 (4.20.0-r0)
(11/16) Installing p11-kit (0.25.5-r2)
(12/16) Installing gnutls (3.8.8-r0)
(13/16) Installing numactl (2.0.18-r0)
(14/16) Installing liburing (2.9-r0)
(15/16) Installing zstd-libs (1.5.7-r0)
(16/16) Installing qemu-img (10.0.0-r1)
Executing busybox-1.37.0-r18.trigger
Executing glib-2.84.3-r0.trigger
OK: 54 MiB in 104 packages
***** DOWNLOAD QCOW2 IMAGE *****
(1/7) Installing ca-certificates (20250619-r0)
(2/7) Installing c-ares (1.34.5-r0)
(3/7) Installing libexpat (2.7.1-r0)
(4/7) Installing libgcc (14.2.0-r6)
(5/7) Installing sqlite-libs (3.49.2-r0)
(6/7) Installing libstdc++ (14.2.0-r6)
(7/7) Installing aria2 (1.37.0-r1)
Executing busybox-1.37.0-r18.trigger
Executing ca-certificates-20250619-r0.trigger
OK: 61 MiB in 111 packages
https://d2lzkl7pfhq30w.cloudfront.net/pub/fedora/linux/releases/42/Cloud/x86_64/images/Fedora-Cloud-Base-Generic-42-1.1.x86_64.qcow2

07/17 20:05:18 [NOTICE] Downloading 1 item(s)
[#73303d 0B/0B CN:1 DL:0B]
[#73303d 0B/0B CN:1 DL:0B]
[#73303d 192KiB/507MiB(0%) CN:4 DL:198KiB ETA:43m36s]
[#73303d 3.5MiB/507MiB(0%) CN:4 DL:1.7MiB ETA:4m55s]
[#73303d 14MiB/507MiB(2%) CN:4 DL:4.8MiB ETA:1m41s]
[#73303d 25MiB/507MiB(5%) CN:4 DL:6.3MiB ETA:1m15s]
[#73303d 37MiB/507MiB(7%) CN:4 DL:7.4MiB ETA:1m3s]
[#73303d 48MiB/507MiB(9%) CN:4 DL:8.0MiB ETA:56s]
[#73303d 59MiB/507MiB(11%) CN:4 DL:8.5MiB ETA:52s]
[#73303d 71MiB/507MiB(13%) CN:4 DL:8.8MiB ETA:49s]
[#73303d 82MiB/507MiB(16%) CN:4 DL:9.1MiB ETA:46s]
[#73303d 93MiB/507MiB(18%) CN:4 DL:9.3MiB ETA:44s]
[#73303d 104MiB/507MiB(20%) CN:4 DL:10MiB ETA:38s]
[#73303d 116MiB/507MiB(22%) CN:4 DL:11MiB ETA:34s]
[#73303d 127MiB/507MiB(25%) CN:4 DL:11MiB ETA:33s]
[#73303d 138MiB/507MiB(27%) CN:4 DL:11MiB ETA:32s]
[#73303d 149MiB/507MiB(29%) CN:4 DL:11MiB ETA:31s]
[#73303d 160MiB/507MiB(31%) CN:4 DL:11MiB ETA:30s]
[#73303d 172MiB/507MiB(33%) CN:4 DL:11MiB ETA:29s]
[#73303d 183MiB/507MiB(36%) CN:4 DL:11MiB ETA:28s]
[#73303d 194MiB/507MiB(38%) CN:4 DL:11MiB ETA:27s]
[#73303d 205MiB/507MiB(40%) CN:4 DL:11MiB ETA:26s]
[#73303d 217MiB/507MiB(42%) CN:4 DL:11MiB ETA:25s]
[#73303d 228MiB/507MiB(45%) CN:4 DL:11MiB ETA:24s]
[#73303d 239MiB/507MiB(47%) CN:4 DL:11MiB ETA:23s]
[#73303d 250MiB/507MiB(49%) CN:4 DL:11MiB ETA:22s]
[#73303d 262MiB/507MiB(51%) CN:4 DL:11MiB ETA:21s]
[#73303d 273MiB/507MiB(53%) CN:4 DL:11MiB ETA:20s]
[#73303d 284MiB/507MiB(56%) CN:4 DL:11MiB ETA:19s]
[#73303d 295MiB/507MiB(58%) CN:4 DL:11MiB ETA:18s]
[#73303d 306MiB/507MiB(60%) CN:4 DL:11MiB ETA:17s]
[#73303d 318MiB/507MiB(62%) CN:4 DL:11MiB ETA:16s]
[#73303d 329MiB/507MiB(64%) CN:4 DL:11MiB ETA:15s]
[#73303d 340MiB/507MiB(67%) CN:4 DL:11MiB ETA:14s]
[#73303d 351MiB/507MiB(69%) CN:4 DL:11MiB ETA:13s]
[#73303d 362MiB/507MiB(71%) CN:4 DL:11MiB ETA:12s]
[#73303d 374MiB/507MiB(73%) CN:4 DL:11MiB ETA:11s]
[#73303d 385MiB/507MiB(75%) CN:4 DL:11MiB ETA:10s]
[#73303d 396MiB/507MiB(78%) CN:4 DL:11MiB ETA:9s]
[#73303d 407MiB/507MiB(80%) CN:4 DL:11MiB ETA:8s]
[#73303d 419MiB/507MiB(82%) CN:4 DL:11MiB ETA:7s]
[#73303d 430MiB/507MiB(84%) CN:4 DL:11MiB ETA:6s]
[#73303d 441MiB/507MiB(87%) CN:4 DL:11MiB ETA:5s]
[#73303d 452MiB/507MiB(89%) CN:4 DL:11MiB ETA:4s]
[#73303d 464MiB/507MiB(91%) CN:3 DL:11MiB ETA:3s]
[#73303d 475MiB/507MiB(93%) CN:3 DL:11MiB ETA:2s]
[#73303d 486MiB/507MiB(95%) CN:3 DL:11MiB ETA:1s]
[#73303d 497MiB/507MiB(98%) CN:3 DL:11MiB]

07/17 20:06:06 [NOTICE] Download complete: /installer/cloud_image.qcow2

Download Results:
gid |stat|avg speed |path/URI
======+====+===========+=======================================================
73303d|OK | 10MiB/s|/installer/cloud_image.qcow2

Status Legend:
(OK):download completed.
***** DD QCOW2 *****
Waiting for qcow file to be mounted...
/dev/nbd0: PTUUID="a23af222-89e4-41f1-8e8f-9bccdacbb102" PTTYPE="gpt"
OK: 61 MiB in 111 packages
(1/4) Installing lzo (2.10-r5)
(2/4) Installing eudev-libs (3.2.14-r5)
(3/4) Installing btrfs-progs (6.14-r0)
(4/4) Installing btrfs-progs-openrc (6.14-r0)
Executing busybox-1.37.0-r18.trigger
OK: 63 MiB in 115 packages
/dev/nbd0p4, ID: 1
Device size: 3.92GiB
Device slack: 3.50KiB
Data,single: 1.23GiB
Metadata,DUP: 512.00MiB
System,DUP: 16.00MiB
Unallocated: 2.18GiB

Done, had to relocate 0 out of 6 chunks
/dev/nbd0p4, ID: 1
Device size: 3.92GiB
Device slack: 3.50KiB
Data,single: 1.23GiB
Metadata,DUP: 512.00MiB
System,DUP: 16.00MiB
Unallocated: 2.18GiB

Resize device id 1 (/dev/nbd0p4) from 3.92GiB to 1.84GiB
Warning: Shrinking a partition can cause data loss, are you sure you want to continue?

Yes/No? yes
Information: You may need to update /etc/fstab.

/dev/nbd0 disconnected
Image resized.
Waiting for qcow file to be mounted...
Waiting for qcow file to be mounted...
Waiting for qcow file to be mounted...
Waiting for qcow file to be mounted...
Waiting for qcow file to be mounted...
Waiting for qcow file to be mounted...
Waiting for qcow file to be mounted...
Waiting for qcow file to be mounted...
Waiting for qcow file to be mounted...
Waiting for qcow file to be mounted...
Waiting for qcow file to be mounted...
Waiting for qcow file to be mounted...
Waiting for qcow file to be mounted...
Waiting for qcow file to be mounted...
Waiting for qcow file to be mounted...
Waiting for qcow file to be mounted...
Waiting for qcow file to be mounted...
Waiting for qcow file to be mounted...
Waiting for qcow file to be mounted...
Waiting for qcow file to be mounted...
Waiting for qcow file to be mounted...
Waiting for qcow file to be mounted...
Waiting for qcow file to be mounted...
Waiting for qcow file to be mounted...
```

Start with reinstall.log at the `DD QCOW2` step and trace the installer path that emits `Waiting for qcow file to be mounted...`. Compare the expected `/dev/nbd0` state before and after `qemu-nbd --connect=/dev/nbd0 /installer/cloud_image.qcow2`, then reproduce the Fedora 42 installation from TencentOS Server 3.1. Done means the qcow image reconnects automatically and installation proceeds without manual SSH intervention.

Written by the indexing model from the issue text.