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Parallel zfs mounting

Authored by on Feb 7 2019, 10:12 AM.
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This patch implements parallel mounting for zfs filesystems. This was first implemented on Illumos and ported to ZOL. After asking on the zfs-devel mailing list it was suggested that I start with the ZOL patch because it would be easier to port.

Delphix has seen huge decrease in latency of the mount phase with this patch (see results here: Performance improvements measured at Gandi are on par with those at Delphix.

Mailing thread here:

Porting Notes:


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rS FreeBSD src repository - subversion
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kib edited reviewers, added: avg; removed: kib.Feb 7 2019, 10:34 AM
kib added a subscriber: kib.

Some updates:

This feature is listed here: as not yet implemented for FreeBSD.
As far as I understand, FreeBSD is planning to rebase on ZoL. If this is the case we will get this feature for free with ZoF, so depending on how soon the rebase will this patch may or may not be useful to merge.

I haven't thoroughly examined the change, but the procedure you followed sounds good to me.
And if it works, then it is good enough for me.

Also, after this is committed it would make sense to do a "record only" merge from the illumos vendor area for the corresponding illumos commit.

This revision is now accepted and ready to land.Feb 22 2019, 11:56 AM
sef added a subscriber: sef.

Seems generally fine to me, although I haven't looked at the ZoL side for comparison.

This revision was automatically updated to reflect the committed changes.