VSS using all the CPU, File Explorer incredibly slow

[MrYossu]

Hello, not sure how much of this info is relevant, but I'm including it just in case. System specs at the bottom.

On Sun 19th Nov, I started my PC up, and was greeted with a message saying there was a big update to Windows10, and did I want to restart my PC. I said no, and rescheduled it for later. During the day, I installed Hyper-V. At some point in the afternoon, I noticed that my PC was grinding along, and the CPU desktop widget I have showed all 8 cores at around 98% activity.

Any attempt to use File Explorer was very painful. I could double-click a folder, and it would take about 5 seconds to open it. Even when it opened it, I often got "Working on it" for a few seconds before the files showed. As often as not, when I double-clicked, nothing happened at all. Sometimes it opened the textbox to rename the folder (despite me double-clicking), sometimes it just didn't do anything.

This happened on both of my main disks (C: and D:, see specs below), one of which is an SSD, so it's not like the device itself is going slowly.

As Windows was driving me mad about updating (so much for scheduling it for later!), I eventually gave up and restarted. The problem persisted. After a few days of trying to sort it out, a friend mentioned that it might be Hyper-V that was the cause. I uninstalled it, restarted, and all seemed well for a day or so. Then it started again.

The same friend suggested I use the Windows Performance Recorder. He had a look at a recording, and said that it looked like the Volume Shadow Copy service was the problem. As an experiment, I disabled this service, and indeed, the machine was back to its normal speed.

For (hopefully) obvious reasons, disabling VSS isn't a viable option, so I enabled it again. Sure enough, the problem came back. However, I can't work like this, my machine is crippled.

Edit: I just tried stopping the VSS service, and File Explorer was still slow, so maybe that was a red herring. I have noticed that the CPU meter doesn't always show high CPU usage when I'm having the issue, but very often I see the "NT Kernel & System" entry in Task Manager at the top of the list when ordered by CPU usage. Don't know if that helps.

Anyone any idea what could have gone wrong, and what I can do about it? Don't know if I've given all the relevant info, please ask if there is anything more I can supply.

Thanks in advance for any help you can give.

System specs
Dell Precision T5810 Interl Xeon E5-1630 v3 @ 3.70GHz
40Gb RAM - generally have about 20Gb free
C: drive 1Tb SSD - main system drive, 640Gb free
D: drive 1Tb HDD - pictures, downloads, etc, 220Gb free
F: drive 6Tb HDD - holds Macrium Reflect disk images, Windows File history, 3.1Tb free
Windows 10 64-bit Professional

P.S. After posting, I tried stopping the VSS service, and File Explorer was just as slow, so it might not be VSS after all.

 

[Lutfij]

Do you have any updates pertaining to your BIOS? Are we looking at the Dell Precision 5180 or the 5810? Since you're on Windows 10, see if a repair install changes anything for you.

 

[MrYossu]

Sorry, 5810. I updated the question.

A repair install looks like it will take some time, so will have to wait until later. Thanks for the quick reply

 

[Solandri]

Most of the times I've seen symptoms like this, it's a failing drive or faulty cable/connector. When a drive has trouble reading a sector, it tries over and over again, up to about a minute (at which point the OS gives the infamous "abort, retry, fail?" dialog). During this time, because the drive is busy trying to process that one read request, it can't handle other requests. And the system appears to lag, especially file explorer. But if you give it enough time, it eventually works. That you're seeing this with multiple programs and services all related to heavy disk activity (Hyper-V, VSS, Windows Update) supports this. Trying more read operations (like error scans, repair installs, etc) just exacerbates the problem, so I don't recommend immediately jumping to those as an attempt to fix things.

First thing I'd try is to disconnect both your HDDs in case one of them is the culprit. See if the system behaves normally with just your SSD connected (i.e. assume the SSD is not having problems). If everything works OK without HDDs, then it's a simple matter to narrow down which HDD is having problems, and determine if the problem is the drive or connector or cable, and replace it (could be as simple as moving the cable to a different connector).

If the problems persist even with just the SSD, then (assuming it's SATA) try making sure the cable is firmly seated, changing the cable, or plugging it into a different SATA port (sometimes an individual port can go bad). I doubt it's the SSD though, or you'd have noticed that updating was taking an incredibly long time. You didn't by chance put a pagefile on one of the HDDs to try to save your SSD from pagefile writes? (Windows uses the pagefile even if it has lots of free RAM.)

But my bet is that one of the HDDs is going. Sometimes a bearing or something shifts, causing the read/write heads to misalign slightly with the written tracks, making it difficult for it to read previously-written data. Or some of the platter surface material flakes off and bounces around inside as the disk spins, thereby scraping off more material progressively making it harder for the drive to read data as time goes by. The data is sorta readable, but the drive has to try dozens of times before what it reads matches the CRC check. Uninstalling Hyper-V or disabling VSS may have helped temporarily because that freed up disk space which wasn't yet affected by the problem. But once that space had been filled with new data, the drive went back to trying to read/write on the problem spaces, and the problem returned.

 

[MrYossu]

Well, I did the repair, which took about 90 minutes, and when it was done, Windows refused to recognise two of my monitors. However, and a restart, it seems to be OK.

I'm happy to report that so far it's running fine. I'm not holding my breath, as it's often like this right after a restart. I'll have to see how it goes over the next couple of days and see if it stays this responsive.

Solandri, given that it's running fast now, can we count out disk problems, or do you still think I need to investigate further? I can navigate both main disks in File Explorer, and it responds instantly. Does that mean the drives are fine?

Thanks to both of you for your help. I'll let you know how it goes.

 

[Solandri]

Solandri, given that it's running fast now, can we count out disk problems, or do you still think I need to investigate further? I can navigate both main disks in File Explorer, and it responds instantly. Does that mean the drives are fine?

It depends on what the cause was. If it was some of your system files being corrupt, then yeah the repair should have taken care of the problem. If it was some of your system files being on corrupt parts of your disk/SSD, then all the repair did was move them to sectors which are not having problems (for now).

Hope for the best, plan for the worst. Assume the problem is solved, but make sure you keep your backups up to date. Glad you got it taken care of.

 

[MrYossu]

Assume the problem is solved, but make sure you keep your backups up to date.

I use Macrium Reflect to do nightly disk images of the C drive and Windows Backup / File History on both my C and D drives. Is that enough, or is there anything else you recommend?

Thanks again

 

[MrYossu]

Sad to report, but it seems to be doing it again 🙁

Anyone any ideas?

 

[ernesti.kyostila]

I had this problem for over a month and found the culprit today. It was very painful to try to browse the directories, the explorer process taking a lot of CPU and time. It sometimes took a couple of minutes to open a file.

The rogue was a small piece of software called Traystatus. It was sitting in the system tray, indicating if NumLock was on. I removed it and the Explorer was responsive again, at least so far.

I suspect there are other utilities that may cause the same kind of behaviour. It might be a good idea to try disabling some of them should one have installed something like the one I had.

 

[MrYossu]

Glad you got it sorted. Sadly, this wasn't the case for me. I checked everything installed, and everything running, and couldn't pin it down to anything specific. After a couple of very painful months, trying more things than I ever even knew about, I gave up and went back to Win7. Haven't had a single problem since!

As it happens, my son's lap top is also extremely slow. We've reinstalled Windows 10 over and over again, and even with a vanilla install and a minimum of software, it can drag along. My impression is that Win10 has a serious problem in this respect. Cases like yours just make a bad problem even worse.

 

[Peter Martin]

I have a super weak A6 powered Notebook that is a little rocket on Windows 10. this is a config issue. When you install, you need to do a CLEAN install, wiping all partitions, having only the boot drive connected.

they should not even allow upgrades from crappy windows 7. too problematic. if you go win10, boot to USB, blast your SSD and install it. problems solved.

 

[MrYossu]

Been there, done that. Wiped all partitions, started from a clean drive, doesn't make any difference. I have never upgraded form one version of Windows to another, don't trust them to do it properly.

 

[Peter Martin]

one of the hdds is probably going, can you disconnect all but ssd and start from there? is it stable? etc. test

 

[MrYossu]

Peter, was that directed at me? If so, it's no longer relevant. I went back to Win7 some months ago, and haven't had any problems since. Not going to Win10 in the foreseeable future.

Thanks anyway.

 

[MrYossu]

P.S. As it happens, I tried it using only the SSD, and had the same problem.