Allan Jude

@allanjude
866 Followers
26 Following
37 Posts
ZFS Engineering Manager @ Klara
FreeBSD and OpenZFS developer
Host of Downstream, BSDNow, and 2.5 Admins podcasts

@joeress I so seldom heard that sound, because I've generally left my computers on 24/7. so usually that sound was something of a milestone, like a hardware upgrade or something.

I guess back in college that sound meant "I'm going home for the weekend", which maybe is why it sparks joy.

I've been using #FreeBSD since 1995. 31 years, more or less.

I was never aware of this most vital community resource.

https://wiki.freebsd.org/Community/Dogs

Community/Dogs - FreeBSD Wiki

@platymew @25admins
It is a bit more complex than a "5 second rule". Basically, a TXG will be open for UP TO 5 seconds, but if there is a lot of data that has changed, it'll end early.

When you create a snapshot, it also ends the currently open transaction group early.
So, when you (or better yet, your automated tooling) runs `zfs snapshot`, anything that has been written by an application up to that point, is written out atomically as part of the snapshot.

GitHub is broken. Post memes.
@woodsb02 @kithrup
There is more about the rewrite feature in Klara's recent webinar: https://klarasystems.com/webinars/new-year-new-zfs-what-2-4-brings/
A New Year, A New ZFS: What 2.4 Brings to the Table - Klara Systems

Join us for a deep dive into the ZFS 2.4 release and learn about new performance, stability, and observability updates plus when to upgrade.

Klara Systems

@kithrup @woodsb02

Yeah, as Sean said, rewrite operates one file at a time, and encryption has to be set at dataset creation time.

Rewrite can change: compression, checksum, copies, dedup, etc.

But not recordsize (file creation time), or encryption (dataset creation time)

@csyn @25admins Yes, use a raw file instead of qcow2, (since you already get COW from ZFS). You can use qemu-img (with preallocation off to save time/space) or just the `truncate` command to create it.

If you are going to use a qcow2 file, as Jim said, set the parameters in qemu-img to make it with an internal 16kb size.

virtiofs and 9p are nice for convenience, but I wouldn't recommend for a database.

@mdavis Do you have the actual error messages handy?

A number of others have done most of the heavy lifting on certctl recently.

The team at Klara is working on some improvements, and possibly a rewrite in C to make it faster too. Would be happy to pass on the details (or a bugzilla link) to make sure it gets fixed.

@shom @jimsalter @numbleroot @joeress Haha.

I remember going to Japan with 3 laptops, and getting funny looks. I don't care that many anymore, my old-man back can't do it.

@laydros @joeress @numbleroot @jimsalter Recompiling ZFS only takes a minute or two, it isn't like you have to recompile the linux kernel at each upgrade