Re: Testing bcachefs - beginners questions

On Fri, 18 Mar 2016, Eric Wheeler wrote:

On Thu, 17 Mar 2016, Kent Overstreet wrote:

quoted

since the announcement. I'm gonna have to write some more documentation and do
another announcement soon.

One thing to note if you're running benchmarks is that data checksumming is on
by default - it doesn't hurt most stuff noticably, but small random reads where
your read size is smaller than the checksum granularity (typically the size of
the writes you issued) will suck because it'll have to bounce and read the
entire chunk of data the checksum covered.

Benchmark wise, here's a dio append benchmark I ran the other day:

Summary:
bcachefs:       1749.1 MB/s
ext4:           513.6 MB/s
xfs:            515.7 MB/s
btrfs:          531.2 MB/s

Wow, that is incredible.  For an upper limit on the extX filesystem line, 
would you run a benchmark on your hardware for ext2 or ext4 without 
journal?

Hey Kent,

Have you had a chance to see how much faster bcache is compared to ext2 or 
ext4-no-journal on your hardware?  I'm curious about performance without 
journaling.

-Eric


--
Eric Wheeler