Version 9.5.2 Released Today

Hello Tim,

I asked one of the developers to investigate this, here is the answer:

I created a sparse bundle image, and copied the El Capitan installer to it.  After this, there was a sustained 30% cpu usage for about 2 minutes from process diskimages-helper as it accessed in turn each file component of the sparse bundle.  Once that was completed, CPU usage dropped to normal levels.

This was using the SSD drive of my iMac.  On a removable USB stick this process is likely to be much slower, and may well cause a higher CPU usage.

Insight into which file is being scanned is available by using the following command in Terminal:

   $  nc -U /var/run/com.sophos.diagnostics.view | grep "oas perf"

Hope that helps explain what is going on. The diagnostics log can be very useful to figure out what is happening in a case like this.

We identified an issue which causes slow Time Machine backups, and our next release should include a fix.  In the mean time, you can disable background process throttling in order to speed up your backups:

sudo sysctl debug.lowpri_throttle_enabled=0

William

Hello Christopher,

Thanks for the report. We haven't been able to reproduce this, and wanted to ask a couple of questions:

1. are you using "Scan Network Volumes" in the on-access scanner? if so, does the problem disappear if you turn it off?
2. I'm guessing the problem will disappear if you aren't using on-access scanning, but good to confirm
3. can you share a bit more about the NAS that you are using? we are curious why the compression library is involved

Much appreciate the assistance.

litanyww said:

We identified an issue which causes slow Time Machine backups, and our next release should include a fix.  In the mean time, you can disable background process throttling in order to speed up your backups:

sudo sysctl debug.lowpri_throttle_enabled=0

William

Since disabling background process throttling via that command appears to be permanent (at least until the next release), what would we be giving up?

And can I assume that setting enabled=1 will turn it back on? I normally I just turn On-Access Scanning off during the TM backup but the Terminal command is quicker.

I don't know what "background process throttling" is?? Is this the same as on-access scanning?? Please advise.

The key question is when you expect to release a fix for Time Machine problem. An estimate, even though not guaranteed, would be very helpful. Please advise.

...

Hi have the same problem with macos sierra and sophos home.

If can help here my answer

1. the home edition doesn't have this feature. does it?

2. correct

3. i use a nas dlink and and time capsule vm based on linux. on both of them TM stopped to work after macos sierra installation 

I think that debug.lowpri_throttle_enabled=0 isn't a solution because it will affect every low priority throttle from anything at the kernel level.

so at the moment "i solve" disabling sophos home.

hope you solve quickly because it's very frustrating.

.

hellohgjytrjytr said:

I don't know what "background process throttling" is?? Is this the same as on-access scanning?? Please advise.

The key question is when you expect to release a fix for Time Machine problem. An estimate, even though not guaranteed, would be very helpful. Please advise.

I don't know what "background process throttling" is either though I suspect it involves favoring current activity performance over the stuff going on under the hood (probably such as Sophos On-Access Scanning which is why the throttling is set to off), and since the setting appears more general than just Sophos-related, I'm concerned what other  processes might be affected by turning background throttling off.

Please note that I'm just a Sophos user like you, not an expert and don't know when the fix will be released either, though I suspect it'll be when it's ready, unlike, seemingly, macOS Sierra.[;)]

Update: Some researching resulted in more information about background process throttling. This link provides a discussion and some cautions regarding such throttling. Personally, I'll wait for the Sophos update and just turn off On-Access Scanning only when running a TM backup (that's one of the advantages of running TM manually as needed rather than automatically).

I cannot find a download link for Sophos Anti-Virus Home Edition 9.5.2.  I have it installed on my Mac and would like to install it on my parents', but all I can find are links to Sophos Home.  I strongly prefer the non-cloud based user interface on Sophos Anti-Virus Home Edition.  In particular the ability to schedule scans easily.