@Vahric, FYI, if you use directio, instead of sync (like a database is is
default configured for), you will just be using the RBD cache. Look at the
latency on your numbers. It is lower than is possible for a packet to
traverse the network. You'll need to use sync=1 if you want to see what the
perf
If fault domain is a concern, you can always split the cloud up into 3
regions, each having a dedicate Ceph cluster. It isn't necessarily going to
mean more hardware, just logical splits. This is kind of assuming that the
network doesn't share the same fault domain though.
Alternatively, you can s
We are in the same boat. Can't get rid of ephemeral for it's speed, and
independence. I get it, but it makes management of all these tiny pools a
scheduling and capacity nightmare.
Warren @ Walmart
On Wed, Feb 17, 2016 at 1:50 PM, Ned Rhudy (BLOOMBERG/ 731 LEX) <
erh...@bloomberg.net> wrote:
> T
There are some cases where it may be easier to run them as separate clusters.
Like when you start adding tuning changes that don't make sense for types of
clusters. Like the recent tcmalloc/jemalloc discovery for SSDs. I'm not sure
that makes sense for spinners, and that is at a library level, n
The only time we saw major performance issues with ephemeral (we're using
SSDs in RAID 0) was when we ran fio against a sparse file. It sounds like
you ran it against a properly filled file though, and it looks like you're
on a single spinning drive, based on the fio numbers. Can you confirm?
Also,
I'm gonna forward this to my co-workers :) I've been kicking this idea
around for some time now, and it hasn't caught traction. I think it could
work for a modest overcommit, depending on the memory workload. We decided
that it should be possible to do this sanely, but that it needed testing.
I'm h
ss ideally, we would have host aggs for each type, and both raw and
qcow2 versions of images. I fear user education would be challenging though.
Warren
Warren
On Thu, May 28, 2015 at 3:55 PM, Jonathan Proulx wrote:
> On Thu, May 28, 2015 at 3:34 PM, Warren Wang wrote:
> > Even though
Even though we're using Ceph as a backend, we still use qcow2 images as our
golden images, since we still have a significant (maybe majority) number of
users using true ephemeral disks. It would be nice if glance was clever
enough to convert where appropriate.
Warren
Warren
On Thu, May 28, 2015
I would avoid co-locating Ceph and compute processes. Memory on compute
nodes is a scare resource, if you're not running with any overcommit, which
you shouldn't. Ceph requires a fair amount (2GB per OSD to be safe) of
guaranteed memory to deal with recovery. You can certainly overload memory
and r
Your understanding is correct. I have the same problem as well. For now, my
plan is to just move cinder-volume to our more robust hosts, and run
database changes to modify the host, as needed.
I have noticed a growing trend to replace the host parameter with a
generic, but I agree that this presen
It would be nice to have an archive status for images, where brand new
instances may not be launched off it, but where it may be used as a
reference for existing instances and snapshots.
Not sure about other folks, but we just keep piling up the old images, and
they have to remain public. There's
If you want to use Galera + mysql, make sure you have haproxy set to prefer
a single host, otherwise you will have deadlocking problems. I know it kind
of defeats the purpose of having an all active database setup, but that's
what we've had to do. My other advice would be to use SSDs if you can
aff
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