copy failure

[Dan Lester]

I'm doing a backup to a new Crucial 500GB SATA SSD. The progress of the copy-after-erase backup is confusing. With a 160GB total, "Replicating System Volume" starts out increasing fast, but then slows dramatically. It's half done in three minutes, and then the last 10GB takes more than thirty minutes.

Most of my other backups take place automatically, at night, so I don't watch their progress. Is this strange progress rate normal?

But then it starts "Replicating Data Volume" and SuperDuper soon gives up, with a "Failed to copy".

Log says "Completed System Volume Replication", but then while it is "Replicating Data Volume" I get

Volume replication failed - error 49158
Error | ***ERROR OCCURRED: ****FAILED****: result=256 errno=60 (No such process)

This failure happens repeatedly. What's going on?

In DiskUtility, this disk looks to be set up the same as the others.

[dnanian]

Please send the log with the send to shirt pocket button and I'll take a look.

(Apple's replicator gives minimal status and so it's not weird that it would look...weird.)

[Dan Lester]

Thanks. Logs sent. So you're saying that the very uneven progress rate is not unexpected, and it's really the fault of the Apple OS? In the past, when I've watched a SD backup, I don't remember the progress being so uneven.

[dnanian]

When replicating, the replicator gives minimal feedback, and yes, it can be erratic. But your logs also showed drive failures, which likely contributed to the weirdness as well.