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Mention ZFS zio nop-write improvement.

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Craig Rodrigues 2013-12-22 10:58:40 +00:00
parent ebee380515
commit e1c330759c
1 changed files with 8 additions and 0 deletions
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8
release/doc/en_US.ISO8859-1/relnotes/article.xml
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@ -342,6 +342,14 @@
<para revision="252140">Support for L2ARC compression has been added to ZFS.</para>
<para revision="243524">The zio nop-write improvement from Illumos
was imported into &os;. To reduce I/O, nop-write skips overwriting
data if the checksum (cryptographically secure) of new data
matches the checksum of existing data. It also saves space if
snapshots are in use. This improvement only works only on
datasets with enabled compression, disabled deduplication and
sha256 checksums.</para>
<para>ZFS will now compare the checksums of incoming writes to
the checksum of the existing on-disk data and avoid issuing any
write I/O for data that has not changed. This will reduce I/O