dedup table, is it data or metadata?

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dedup table, is it data or metadata?

Postby haer22 » Wed Jun 08, 2016 11:11 am

Is the dedup table regarded as "data" or "metadata", i.e. is it written once like data or twice like meta-data?
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Re: dedup table, is it data or metadata?

Postby rottegift » Tue Jun 28, 2016 10:03 am

It's treated as metadata and additionally you can cause extra ditto copies with "zpool dedupditto=number" where number is >= 100 or is zero (the default); when the reference count for a table entry goes above number when number is nonzero, the (many-entry) record it's in will be ditto-copied (see zio_ddt_write() for details).

Don't do deduplication on ANY pool where ANY device in the pool has a nonzero seek time. You'll be sorry eventually.
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