Re: Slow dc3dd in 3.18 on x86

[Martin K. Petersen]

>>>>> "Michael" == Michael L Semon <mlsemon35@xxxxxxxxx> writes:

Michael> This week, a simple `dc3dd wipe=/dev/sda5` operation had speeds
Michael> cut from 10-15 MB/s down to less than 1.8 MB/s.  With this
Michael> method, syncs took so long that magic SysRq keys were needed to
Michael> stop the PC.  A bisect let me here:

That commit itself doesn't do anything.

I was concerned that somehow integrity got enabled by accident and you
were bogged down by checksum calculations but I see no evidence that
this would be happening. Ran a few tests on ATA systems here.

So I'm puzzled.

Please let me know if the disk has an integrity profile in sysfs.

-- 
Martin K. Petersen	Oracle Linux Engineering
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