FingerlessGloves
Anyone able to give me a quick explanation, of Scanned and Issue on a ZFS scrub.
2.38T scanned at 6.70G/s, 260G issued at 731M/s, 39.6T total 0B repaired, 0.64% done, 15:41:32 to go
I’ve tried googling it but the explanation is lacking or just not easy to get what their getting at.
Lalufu
scrub is a two phase process.
the scan phase is gathering everything that is to be scrubbed, this is then sorted into an order that will result in mostly linear, large reads (because this is faster), and then issued to to the actual scrub
this is running in parallel
the scan phase produces very high throughput because it’s not actually reading the data, it’s just inspecting the metadata and uses that to sort
the «issued» stage is doing the actual reading of data
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Иван Лежнёв IV 