ChatGPT 有多强：用 ChatGPT 使 qcow2 容量与实际相符: Difference between revisions
Created page with "不同类型的Guest机有不同解决方式，基本思路就是用0填充未使用的客户机磁盘空间，然后用qemu-img转换磁盘镜像文件，转换后的磁盘镜像文件将只包含所有已使用的磁盘空间。致谢 [http://bbs.chinaunix.net/thread-3728461-1-1.html 这篇博客] {| class="wikitable" |我 | Hi, I have a KVM Windows 10 guest, its C:\ disk is just 50G, but the host /home/user/Documents/win10.qcow2 is 93G. How to let the 93G smaller as..." |
No edit summary |
||
| (One intermediate revision by the same user not shown) | |||
| Line 15: | Line 15: | ||
For example, you can use SDelete to zero out free space on the C: drive: | For example, you can use SDelete to zero out free space on the C: drive: | ||
<syntaxhighlight lang="powershell" | <syntaxhighlight lang="powershell"> | ||
sdelete -z C: | sdelete -z C: | ||
</syntaxhighlight> | </syntaxhighlight> | ||
| Line 22: | Line 22: | ||
<b>3. Resize the Virtual Disk</b>: Use the <code>qemu-img</code> command to resize the qcow2 image file. The following command resizes the image to 50GB (which matches the size of the C:\ disk in your guest): | <b>3. Resize the Virtual Disk</b>: Use the <code>qemu-img</code> command to resize the qcow2 image file. The following command resizes the image to 50GB (which matches the size of the C:\ disk in your guest): | ||
<syntaxhighlight lang="bash" | <syntaxhighlight lang="bash"> | ||
qemu-img resize /home/user/Documents/win10.qcow2 50G | qemu-img resize /home/user/Documents/win10.qcow2 50G | ||
</syntaxhighlight> | </syntaxhighlight> | ||
<b>4. Run a Compaction Operation</b>: You need to perform a compaction operation to reclaim the unused space. Use the `qemu-img` command with the `convert` subcommand and the <code>--shrink</code> option: | <b>4. Run a Compaction Operation</b>: You need to perform a compaction operation to reclaim the unused space. Use the `qemu-img` command with the `convert` subcommand and the <code>--shrink</code> option: | ||
<syntaxhighlight lang="bash" | <syntaxhighlight lang="bash"> | ||
qemu-img convert -O qcow2 /home/user/Documents/win10.qcow2 /home/user/Documents/win10_compacted.qcow2 | qemu-img convert -O qcow2 /home/user/Documents/win10.qcow2 /home/user/Documents/win10_compacted.qcow2 | ||
</syntaxhighlight> | </syntaxhighlight> | ||
| Line 34: | Line 34: | ||
<b>5. Replace the Original Disk Image</b>: After the compaction is complete, you can replace the original disk image with the compacted version. Be sure to back up the original image first if you haven't already: | <b>5. Replace the Original Disk Image</b>: After the compaction is complete, you can replace the original disk image with the compacted version. Be sure to back up the original image first if you haven't already: | ||
<syntaxhighlight lang="bash" | <syntaxhighlight lang="bash"> | ||
mv /home/user/Documents/win10_compacted.qcow2 /home/user/Documents/win10.qcow2 | mv /home/user/Documents/win10_compacted.qcow2 /home/user/Documents/win10.qcow2 | ||
</syntaxhighlight> | </syntaxhighlight> | ||
Latest revision as of 17:21, 29 September 2025
不同类型的Guest机有不同解决方式，基本思路就是用0填充未使用的客户机磁盘空间，然后用qemu-img转换磁盘镜像文件，转换后的磁盘镜像文件将只包含所有已使用的磁盘空间。致谢 这篇博客
| 我 |
Hi, I have a KVM Windows 10 guest, its C:\ disk is just 50G, but the host /home/user/Documents/win10.qcow2 is 93G. How to let the 93G smaller as actual? |
| ChatGPT |
You can reduce the size of the qcow2 disk image file used by your KVM Windows 10 guest by following these steps: Note: Make sure you have a backup of your virtual machine or important data before proceeding, as disk resizing operations can be risky. 1. Zero out Unused Space in the Guest: In the Windows 10 guest, you need to zero out the unused space to allow the qcow2 image to be compacted. You can use a tool like "SDelete" (a Microsoft Sysinternals tool) or any other method to zero out free space on your Windows drive. For example, you can use SDelete to zero out free space on the C: drive: sdelete -z C:
2. Shut Down the Guest: Ensure the Windows 10 guest is powered off before proceeding. 3. Resize the Virtual Disk: Use the qemu-img resize /home/user/Documents/win10.qcow2 50G
4. Run a Compaction Operation: You need to perform a compaction operation to reclaim the unused space. Use the `qemu-img` command with the `convert` subcommand and the qemu-img convert -O qcow2 /home/user/Documents/win10.qcow2 /home/user/Documents/win10_compacted.qcow2
This command creates a compacted copy of your disk image called 5. Replace the Original Disk Image: After the compaction is complete, you can replace the original disk image with the compacted version. Be sure to back up the original image first if you haven't already: mv /home/user/Documents/win10_compacted.qcow2 /home/user/Documents/win10.qcow2
6. Verify Disk Size: Start your KVM Windows 10 guest and verify that the disk size matches the new, smaller size. The above steps should help you reduce the size of the qcow2 disk image file to match the actual space used by the guest's C:\ drive. |