Gluster users - Mar 2018 - [ovirt-users] GlusterFS performance with only one drive per host?

On Mon, Mar 19, 2018 at 5:57 PM, Jayme <jaymef at gmail.com> wrote:
> I'm spec'ing a new oVirt build using three Dell R720's w/
256GB.  I'm
> considering storage options.  I don't have a requirement for high
amounts
> of storage, I have a little over 1TB to store but want some overhead so
I'm
> thinking 2TB of usable space would be sufficient.
>
> I've been doing some research on Micron 1100 2TB ssd's and they
seem to
> offer a lot of value for the money.  I'm considering using smaller
cheaper
> SSDs for boot drives and using one 2TB micron SSD in each host for a
> glusterFS replica 3 setup (on the fence about using an arbiter, I like the
> extra redundancy replicate 3 will give me).
>
> My question is, would I see a performance hit using only one drive in each
> host with glusterFS or should I try to add more physical disks.  Such as 6
> 1TB drives instead of 3 2TB drives?
>
[Adding gluster-users for inputs here]

> Also one other question.  I've read that gluster can only be done in
> groups of three.  Meaning you need 3, 6, or 9 hosts.  Is this true?  If I
> had an operational replicate 3 glusterFS setup and wanted to add more
> capacity I would have to add 3 more hosts, or is it possible for me to add
> a 4th host in to the mix for extra processing power down the road?
>
In oVirt, we support replica 3 or replica 3 with arbiter (where one of the
3 bricks is a low storage arbiter brick). To expand storage, you would need
to add in multiples of 3 bricks. However if you only want to expand compute
capacity in your HC environment, you can add a 4th node.

> Thanks!
>
>
> _______________________________________________
> Users mailing list
> Users at ovirt.org
> http://lists.ovirt.org/mailman/listinfo/users
>
>
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The bottleneck is definitely not the disk speed with glusterFS, no
point of using SSD for bricks what so ever

-v

On Thu, Mar 22, 2018 at 6:01 AM, Sahina Bose <sabose at redhat.com>
wrote:
>
>
> On Mon, Mar 19, 2018 at 5:57 PM, Jayme <jaymef at gmail.com> wrote:
>>
>> I'm spec'ing a new oVirt build using three Dell R720's w/
256GB.  I'm
>> considering storage options.  I don't have a requirement for high
amounts of
>> storage, I have a little over 1TB to store but want some overhead so
I'm
>> thinking 2TB of usable space would be sufficient.
>>
>> I've been doing some research on Micron 1100 2TB ssd's and they
seem to
>> offer a lot of value for the money.  I'm considering using smaller
cheaper
>> SSDs for boot drives and using one 2TB micron SSD in each host for a
>> glusterFS replica 3 setup (on the fence about using an arbiter, I like
the
>> extra redundancy replicate 3 will give me).
>>
>> My question is, would I see a performance hit using only one drive in
each
>> host with glusterFS or should I try to add more physical disks.  Such
as 6
>> 1TB drives instead of 3 2TB drives?
>
>
> [Adding gluster-users for inputs here]
>
>>
>> Also one other question.  I've read that gluster can only be done
in
>> groups of three.  Meaning you need 3, 6, or 9 hosts.  Is this true?  If
I
>> had an operational replicate 3 glusterFS setup and wanted to add more
>> capacity I would have to add 3 more hosts, or is it possible for me to
add a
>> 4th host in to the mix for extra processing power down the road?
>
>
> In oVirt, we support replica 3 or replica 3 with arbiter (where one of the
3
> bricks is a low storage arbiter brick). To expand storage, you would need
to
> add in multiples of 3 bricks. However if you only want to expand compute
> capacity in your HC environment, you can add a 4th node.
>
>>
>> Thanks!
>>
>>
>> _______________________________________________
>> Users mailing list
>> Users at ovirt.org
>> http://lists.ovirt.org/mailman/listinfo/users
>>
>
>
> _______________________________________________
> Gluster-users mailing list
> Gluster-users at gluster.org
> http://lists.gluster.org/mailman/listinfo/gluster-users

On Thu, Mar 22, 2018 at 3:31 PM, Sahina Bose <sabose at redhat.com> wrote:
>
>
> On Mon, Mar 19, 2018 at 5:57 PM, Jayme <jaymef at gmail.com> wrote:
>
>> I'm spec'ing a new oVirt build using three Dell R720's w/
256GB.  I'm
>> considering storage options.  I don't have a requirement for high
amounts
>> of storage, I have a little over 1TB to store but want some overhead so
I'm
>> thinking 2TB of usable space would be sufficient.
>>
>> I've been doing some research on Micron 1100 2TB ssd's and they
seem to
>> offer a lot of value for the money.  I'm considering using smaller
cheaper
>> SSDs for boot drives and using one 2TB micron SSD in each host for a
>> glusterFS replica 3 setup (on the fence about using an arbiter, I like
the
>> extra redundancy replicate 3 will give me).
>>
>> My question is, would I see a performance hit using only one drive in
>> each host with glusterFS or should I try to add more physical disks. 
Such
>> as 6 1TB drives instead of 3 2TB drives?
>>
>
It is possible. With SSDs the rpc layer can become the bottleneck with some
workloads, especially if there are not enough connections out to the server
side. We had experimented with a multi-connection model for this reason:
https://review.gluster.org/#/c/19133/.

-- Manoj
>
> [Adding gluster-users for inputs here]
>
>
>> Also one other question.  I've read that gluster can only be done
in
>> groups of three.  Meaning you need 3, 6, or 9 hosts.  Is this true?  If
I
>> had an operational replicate 3 glusterFS setup and wanted to add more
>> capacity I would have to add 3 more hosts, or is it possible for me to
add
>> a 4th host in to the mix for extra processing power down the road?
>>
>
> In oVirt, we support replica 3 or replica 3 with arbiter (where one of the
> 3 bricks is a low storage arbiter brick). To expand storage, you would need
> to add in multiples of 3 bricks. However if you only want to expand compute
> capacity in your HC environment, you can add a 4th node.
>
>
>> Thanks!
>>
>>
>> _______________________________________________
>> Users mailing list
>> Users at ovirt.org
>> http://lists.ovirt.org/mailman/listinfo/users
>>
>>
>
> _______________________________________________
> Gluster-users mailing list
> Gluster-users at gluster.org
> http://lists.gluster.org/mailman/listinfo/gluster-users
>
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