windows下System Volume Information Folder文件夹过大的处理
本文使用工具应该都要在powershell下，且是管理员权限。
问题：System Volume Information Folder文件夹特别大，
常规操作，不建议
获取权限：
takeown /f "C:\System Volume information"
icacls "C:\System Volume Information" /grant woshub\jwolf:F
手工删除
恢复权限
icacls "C:\System Volume Information" /setowner "NT Authority\System"
icacls "C:\System Volume Information" /remove woshub\jwolf
System Volume Information文件夹里面有啥
- WindowsImageBackup —系统还原点（桌面版本desktop Windows versions ），或者System State backups，使用Windows Server Backup (wbadmin) in server OSs;
- 索引服务（Indexing Service database），用作快速文件搜索 (including Outlook search);
- Distributed Link Tracking Service database;
- Disk snapshots made by Volume Shadow Copy, 可用用来恢复文件旧版本。
- NTFS disk quota settings;
- Base and chunks of the Data Deduplication service;
- DFS Replication database (dfsr.db);
- WPSettings.dat file – created by the storage service (StorSvc);
- USB 盘也会存 IndexerVolumeGuid 文件，定义了 the unique disk label used by the Windows Search service;
- AppxProgramDataStaging, AppxStaging – Windows UWP app backups (it can be used for recovery after removal).
怎样清理System Volume Information文件夹?
不建议手工删System Volume Information文件夹里面的文件。
vssadmin（查看卷影副本）
vssadmin list shadowstorage
你可以减少磁盘占用，使用vssadmin命令：
vssadmin resize shadowstorage /on=[drive letter]: /For=[drive letter]: /MaxSize=[maximum size]
vssadmin Resize ShadowStorage /For=M: /on=M: /MaxSize=30GB
/for=ForVolumeSpec
/on=On VolumeSpec
其中“/for-For VolumeSpec“指定要启用卷影副本的本地卷，而
“/on=On VolumeSpec’"则指定卷影副本的保存卷。
当然，启用卷影副本的卷和保存副本的卷可以是一个卷。
wbadmin
如果你是用系统映像备份system state backups using WSB (Windows Server Backup), 老的系统副本可以删除：
wbadmin delete backup -keepversions:0
wbadmin delete backup -keepversions:1
在Windows Server上，可以使用 diskshadow tool，测试Win10没有。
DiskShadow
Delete shadows OLDEST c:\
清理Dedup ChunkStore in System Volume Information
分析 System Volume Information 文件夹内容, 可能会发现 Dedup\ChunkStore 文件夹占用空间较大。这说明启用了 deduplication feature （去重？重复数据消除功能）
启动删除未使用的chunks,
start-dedupjob -Volume C: -Type GarbageCollection
下一步检查完整性 integrity
start-dedupjob -Volume C: -Type DataScrubbing
监视任务过程，
Get-DedupJob
After the completion of the tasks, unused chunks in the System Volume Information directory will be deleted, and additional disk space will be freed.
Be careful when disabling data deduplication for a volume with the Start-DedupJob -Volume D: -Type Unoptimization command. This command will delete all chunks in the System Volume Information directory and the unoptimized files on the volume will revert to their original size. Therefore, before disabling optimization, make sure that there is enough free disk space.
参考：
How to Clean Up Large System Volume Information Folder on Windows?：
http://woshub.com/how-to-clean-up-system-volume-information-folder/
wbadmin与vssadmin、VssAdmin工具使用详解：
http://t.zoukankan.com/dreamer-fish-p-3439647.html
