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#1
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Disk Cleanup
I occasionally run Windows' Disk Cleanup to purge cruft
left over from updates. I started it today and it reported that it could liberate 21GB! on C:. The list of files to delete included an entry I'd never seen befo "Compress your OS drive" (20GB), but that entry was NOT checked so would be skipped if I pressed OK. Is Cleanup proposing to actually compress the drive or is there a hulking file somewhere that it concludes I don't need? |
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#2
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Disk Cleanup
Jason wrote:
I occasionally run Windows' Disk Cleanup to purge cruft left over from updates. I started it today and it reported that it could liberate 21GB! on C:. The list of files to delete included an entry I'd never seen befo "Compress your OS drive" (20GB), but that entry was NOT checked so would be skipped if I pressed OK. Is Cleanup proposing to actually compress the drive or is there a hulking file somewhere that it concludes I don't need? This is my result today. https://i.postimg.cc/6p4S2Kxm/cleanmgr.gif The OS has the ability to apply NTFS "new style" compression to selected files. The "compact" command is used. There is an attribute that indicates whether the OS is a candidate for compression, but I can't really be sure they know how to operate that properly. I specifically select /CompactOS:never on OS volumes here, forcing Windows to re-expand the crap it compressed. I even do that on the SSD drives. CompactOS is not applied to any of your data partitions, and only applies to C: if/when applicable. In any case, WinSXS (maybe 6GB of stuff), some of the files in there may be candidates for compression. I don't think the intention is to compress System32 "kernel.dll" or equivalent operational files. I thought the design intent was to compress "little used" files, and WinSXS has some of those. In my example picture, the largest numeric value is related to my Downloads folder (which happens to be my work folder and has a Chromium build in it). I have to be careful not to tick the box for "Downloads" in the picture. The "Windows Update Cleanup" could be my SoftwareDistribution, which should really be self-cleaning. I don't plan on ticking the box on that one either. So let's make a list of candidates and see how they match up. Hmmm... Not what i was expecting. Windows Update Cleanup 3.92GB === proposed cleanup SoftwareDistribution 321MB (candidate list) C:\$WINDOWS.~BT approx zero C:\$WINDOWS.~WS approx zero C:\Windows\Installer 3.25GB for 1,755 .msi files (MSI is compressed internally) WinSXS 8.88GB for 63,632 files It's nice that no combination of candidates equals 3.92GB. Maybe that's an estimate of the damage they could do to WinSXS ? ******* I don't generally recommend selecting any compression option as: 1) Compression is slow. 2) It has the potential to fragment things (at least the "old" NTFS compression had that capability. I've noticed that The "write unit" size on Win10 has increased to what could be 64KB, so it's possible they've paved over that problem. 3) Such Compression selections only make sense for 32GB tablets, where the user is fighting with the OS for space. And who doesn't want to do more Flash write cycles on an eMMC chip that requires unsoldering to replace ? Tablets are the perfect place for beating the **** out of Flash. Paul |
#4
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Disk Cleanup
Jason wrote:
In article , lid says... 1) Compression is slow. Yes it is, but tweaked lzw compression allows for very fast expansion. Years ago, IBM added some instructions to the RISC/6000 to perform it. RISC instructions have less entropy than CISC instructions, so it's a win. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus Apparently the Compact command has been given four algorithms, but it doesn't say here which one is used for the /CompactOS option. https://winaero.com/blog/ntfs-lzx-co...hm-windows-10/ LZX XPRESS4K (fastest) (default) XPRESS8K XPRESS16K (LZNT1 is the old compression method as a built-in LZNT1 uses no Reparse Point per file.) In Win10, if you issue compact /compactOS:never and if the files aren't compressed, it takes forever and the command returns 0 of 17983 files decompressed In other words, it takes a while just to check for Reparse points on all the files. I think it's possibly the overhead on selecting the files, that makes it slow. And I've had Cleanmgr.exe spend two or three hours compressing those files. Whatever method they were using, there must have been a complicating factor (Windows Defender scanning each file too?). The compressor that handles WIMs seems to be in the same class as 7Z. It takes a while, and the compression achieved is pretty good. One way to test that, would be to see if 7Z extreme setting, can make storage of Win10 ISOs smaller. Paul |
#5
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Disk Cleanup
On Mon, 11 Feb 2019 22:41:51 -0500, Jason
wrote: In article , lid says... 1) Compression is slow. Yes it is, but tweaked lzw compression allows for very fast expansion. Years ago, IBM added some instructions to the RISC/6000 to perform it. RISC instructions have less entropy than CISC instructions, so it's a win. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus This is *not* an e-mail message you sent, it's a newsgroup posting. And nobody here or in any other text newsgroup cares that Avast checked it for viruses. A text-only message can not be infected with a virus. Please turn off that ad that Avast puts in your messages. It's nothing but spam. |
#6
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Disk Cleanup
Ken Blake wrote:
On Mon, 11 Feb 2019 22:41:51 -0500, Jason wrote: In article , lid says... 1) Compression is slow. Yes it is, but tweaked lzw compression allows for very fast expansion. Years ago, IBM added some instructions to the RISC/6000 to perform it. RISC instructions have less entropy than CISC instructions, so it's a win. --- This email has been checked for viruses by Avast antivirus software. https://www.avast.com/antivirus This is *not* an e-mail message you sent, it's a newsgroup posting. And nobody here or in any other text newsgroup cares that Avast checked it for viruses. A text-only message can not be infected with a virus. Please turn off that ad that Avast puts in your messages. It's nothing but spam. To turn off: Open Avast user interface - Menu - Settings - Protection - Configured shield settings - Mail Shield - untick 'Add a signature to the end of sent emails'. |
#7
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Disk Cleanup
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#8
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Disk Cleanup
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