[MlMt] High Sierra, APFS, Time Machine, and MailMate...

[Steven M. Bellovin]

On 12 Dec 2017, at 16:45, David Blank-Edelman wrote:

> > On Dec 12, 2017, at 1:10 AM, Steven M. Bellovin <smb at cs.columbia.edu 
> <mailto:smb at cs.columbia.edu>> wrote:
>>
>> This dump is to a directly connected USB 2.0 drive. And the CPU is 
>> about 96% idle, according to 'top'.
>
> So, I have to admit I’m still very curious to hear what is in the 
> runtime log and what dtruss says it is actually doing. Wondering if it 
> behaves this way when it hits a specific filesystem object, a specific 
> amount of i/o, etc.
>
> It would be interesting to also know how much i/o is going on (could 
> be seen from activity monitor or a number of other tools) when it 
> stalls. I’m also kind of curious if there are funky things going on 
> with the hardware in this case (the drive, the cable, the connector) 
> that are causing a ton of retries.
>
I'll try to do some monitoring in the next week or two. I'm certain it's 
not hardware -- two different laptops, each talking to both a dedicated 
external hard drive and to a network-resident disk. I see the same 
behavior in all four cases. If it were one machine having trouble to two 
destinations, or both machines having trouble talking to the networked 
disk, I'd look much more seriously at hardware, but here there are 
multiple independent paths showing the exact same symptoms, and this all 
started after the High Sierra/APFS conversion.
>
> P.S. Excellent letter re: FCC.

Thanks!