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A comment on Apple’s big test of data integrity. Parent comment

Re:Apple’s big test of data integrity by w-m on Tuesday May 30, 2023 @06:41PM (#36132087)
Don’t these machines have read speeds of like 5000 MB/s? So just read the 9 GB blockwise and apply a super simple hash. Should be done in two seconds.
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Re:Apple’s big test of data integrity by viraptor on Tuesday May 30, 2023 @09:24PM (#36133408)
If I include the fs overhead, I can shasum a single 23GB file (likely not fragmented) in 46s.

That's uncached, so it's not that quick at boot. 9GB would take ~19s then. Block would go faster, but not an order of magnitude faster.

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Re:Apple’s big test of data integrity by Filligree on Tuesday May 30, 2023 @11:43PM (#36134230)
Single threaded or in parallel?

It's a Merkle tree, apparently, so parallelizing the checksum should be trivial.

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Re:Apple’s big test of data integrity by foobiekr on Wednesday May 31, 2023 @12:26AM (#36134454)
it's IO not CPU bound
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