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<p dir="auto">On 11 Dec 2017, at 13:14, Steven M. Bellovin wrote:</p>
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<div style="white-space:normal"><blockquote style="border-left:2px solid #777; color:#777; margin:0 0 5px; padding-left:5px"><p dir="auto">Seems like an improbable subject line--but is anyone else who uses MailMate on High Sierra/APFS suddenly having serious Time Machine performance issues? I am, on two different laptops. An iMac, which has a hard drive and hence HFS+, is not having any trouble.</p>
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<p dir="auto">Time Machine is working normally for me.</p>
<p dir="auto">You didn’t see what your Time Machine destination is. That would be my first suspect.</p>
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<div style="white-space:normal"><blockquote style="border-left:2px solid #777; color:#777; margin:0 0 5px; padding-left:5px"><p dir="auto">The overall symptom is that backups take *many hours*, with sudden, inexplicable stalls. I say "inexplicable" because Activity Monitor shows essentially no CPU, network, or disk activity -- but the backup just *stops*. I normally don't run MailMate on one of the laptops; its backups complete in a rational amount of time. When I do, it sees the same stalls. In fact, I'm running MailMate on it right now so that I can see what happens on my primary laptop when I exit MailMate. Sure enough, that machine is now behaving.</p>
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<p dir="auto">Note, TimeMachine takes a snapshot when backing up APFS volumes, so there “shouldn’t” be any difference with MailMate running or not. I suspect that’s really a symptom of what the real problem is. </p>
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<div style="white-space:normal"><blockquote style="border-left:2px solid #777; color:#777; margin:0 0 5px; padding-left:5px"><p dir="auto">My suspicion is that the problem has to do with very large directories on APFS file systems, but I don't know that for sure. I have some very large mailboxes, though, and these are of course active when MailMate is running. And of course, that doesn't explain why I don't see any system activity.</p>
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<p dir="auto">Due to the way APFS works, I’d be surprised if that’s the issue. </p>
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<div style="white-space:normal"><blockquote style="border-left:2px solid #777; color:#777; margin:0 0 5px; padding-left:5px"><p dir="auto">Is anyone else seeing this? Does anyone have any work-arounds, other than "don't have such large mailboxes" or "don't run APFS"? I do have a new laptop on order; I'm seriously tempted to reformat it as HFS+ before I start using it.</p>
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<p dir="auto">If that new laptop has an SSD, then APFS is your only choice. </p>
<p dir="auto">-cng</p>
<p dir="auto">-- </p>
<pre style="background-color:#F7F7F7; border-radius:5px 5px 5px 5px; margin-left:15px; margin-right:15px; max-width:90vw; overflow-x:auto; padding:5px" bgcolor="#F7F7F7"><code style="background-color:#F7F7F7; border-radius:3px; margin:0; padding:0" bgcolor="#F7F7F7">Charlie Garrison <charlie@garrison.com.au>
Garrison Computer Services <http://www.garrison.com.au>
PO Box 380
Tumbarumba NSW 2653 Australia
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<p dir="auto"><a href="http://www.ietf.org/rfc/rfc1855.txt" style="color:#3983C4">Conundrum</a></p>
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