Gluster users - Mar 2011 - Any update pls : Req details for "config as like striping with fail over" for many servers

Hi,

Can anybody help me out for my below requirement ?

Regards,
Varadharajan.S


Hi,

I would like to implement glusterfs 3.1 in my concern.We have around 10 servers
and all are holding diff applications such as
webserver(apache,Tomcat),vmware,DNS server....all the servers are having Diff
disk capacity such as 1 TB,2 TB like that.All the systems are having
Ubuntu 10.04

My Requirement:

1.Need to connect all the servers through glusterfs 3.1.x
2.If i configured as Replication method, i am not getting Disk space.So i need
to configure as like striping method.but glusterfs doesn't provide, fail
over
for this.
3.for e.x if i take
server1:/data(120GB),server2:/data(120GB),server3:/home/g1=2TB,server4:/home/g2=2TB......i
want to connect all the servers.so that i can get big storage space for all.if i
go for striping or distributed, if one server fails, i can't access the
volume
and get an error as "Transport end point not connected"

Please let me know the solution and idea for config for this.i am searching in
google for the past 10 days but no proper result.

Regards,
Varadharajan.S

>
> Hi,
>
> I would like to implement glusterfs 3.1 in my concern.We have around 10
> servers
> and all are holding diff applications such as
> webserver(apache,Tomcat),vmware,DNS server....all the servers are having
> Diff
> disk capacity such as 1 TB,2 TB like that.All the systems are having
> Ubuntu 10.04
>
> My Requirement:
>
> 1.Need to connect all the servers through glusterfs 3.1.x
>
Connecting between different machines is not an issue, and 3.1.x onwards
Gluster provides backward/forward compatibility, hence should not be an
issue.

> 2.If i configured as Replication method, i am not getting Disk space.So i
> need
> to configure as like striping method.but glusterfs doesn't provide,
fail
> over
> for this.
>
Yes, thats true. We don't recommend stripe module in general, and I see that
your backend sizes are different... Its preferred  to keep them uniform.


> 3.for e.x if i take
>
>
server1:/data(120GB),server2:/data(120GB),server3:/home/g1=2TB,server4:/home/g2=2TB......i
> want to connect all the servers.so that i can get big storage space for
> all.if i
> go for striping or distributed, if one server fails, i can't access the
> volume
> and get an error as "Transport end point not connected"
>
>
Yes, stripe doesn't give high availability, and any one node failure results
in this error.


> Please let me know the solution and idea for config for this.i am searching
> in
> google for the past 10 days but no proper result.
>
>
Best solution is define your storage need first. (ie, at least in how much
of storage (in TB) you need). Once thats finalized, decide if your
applications really need high availability (i guess 'yes' as this is the
answer in most cases). Get new drives (SATA disks are cheaper now a days),
and try to keep the backend uniform to avoid any possible issues which may
arise later.

Ideally GlusterFS can be configured to work for any scenario if you try to
hand craft your volume file, but as those configs are not getting regular
QA, and can contain corner case issues, we won't recommend such setup
anymore.

Regards,
Amar

Hi Varadharajan.

This is just my opinion, but I would say that the use case you've presented
is not a good match for GlusterFS.

Striping in this file system is not used for expanding the amount of filespace
available - it is used for performance, and only when very very large files are
being stored and accessed, and which may not otherwise fit on a single storage
servers.

Additionally, small file ( <1GB) access tends to be slow and relatively
inefficient on GlusterFS - and unless you are serving very large files on your
webserver, the rest of the applications you mentioned (with the exception of
VMWare) tend to create and use small files.

Please see this link:
http://gluster.qotd.co/q/why-does-gluster-seem-so-slow-accessing-many-small-files/


You can't get high availability / failover without mirroring, and mirroring
with non-uniform amounts of storage on the backend servers is not optimal for
performance, even though it is possible.

Hopefully this helps you understand the issues you face in trying to use the
GlusterFS platform.


James Burnash, Unix Engineering

-----Original Message-----
From: gluster-users-bounces at gluster.org [mailto:gluster-users-bounces at
gluster.org] On Behalf Of s.varadha rajan
Sent: Monday, March 28, 2011 8:16 AM
To: gluster-users at gluster.org
Subject: [Gluster-users] Any update pls : Req details for "config as like
striping with fail over" for many servers

Hi,

Can anybody help me out for my below requirement ?

Regards,
Varadharajan.S


Hi,

I would like to implement glusterfs 3.1 in my concern.We have around 10 servers
and all are holding diff applications such as
webserver(apache,Tomcat),vmware,DNS server....all the servers are having Diff
disk capacity such as 1 TB,2 TB like that.All the systems are having Ubuntu
10.04

My Requirement:

1.Need to connect all the servers through glusterfs 3.1.x 2.If i configured as
Replication method, i am not getting Disk space.So i need to configure as like
striping method.but glusterfs doesn't provide, fail over for this.
3.for e.x if i take
server1:/data(120GB),server2:/data(120GB),server3:/home/g1=2TB,server4:/home/g2=2TB......i
want to connect all the servers.so that i can get big storage space for all.if i
go for striping or distributed, if one server fails, i can't access the
volume and get an error as "Transport end point not connected"

Please let me know the solution and idea for config for this.i am searching in
google for the past 10 days but no proper result.

Regards,
Varadharajan.S


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On 03/28/2011 08:16 AM, s.varadha rajan wrote:
> I would like to implement glusterfs 3.1 in my concern.We have around 10
servers
> and all are holding diff applications such as
> webserver(apache,Tomcat),vmware,DNS server....all the servers are having
Diff
> disk capacity such as 1 TB,2 TB like that.All the systems are having
> Ubuntu 10.04
> 
> My Requirement:
> 
> 1.Need to connect all the servers through glusterfs 3.1.x
> 2.If i configured as Replication method, i am not getting Disk space.So i
need
> to configure as like striping method.but glusterfs doesn't provide,
fail over
> for this.
> 3.for e.x if i take
>
server1:/data(120GB),server2:/data(120GB),server3:/home/g1=2TB,server4:/home/g2=2TB......i
> want to connect all the servers.so that i can get big storage space for
all.if i
> go for striping or distributed, if one server fails, i can't access the
volume
> and get an error as "Transport end point not connected"
> 
> Please let me know the solution and idea for config for this.i am searching
in
> google for the past 10 days but no proper result.
My recommendation would be to take advantage of the fact that you can
serve multiple bricks from one physical machine.  First, divide the
space you'll be using on each machine into multiple bricks so that all
bricks in the cluster will be of approximately equal size.  Then, make
replica pairs containing bricks *on different nodes* and then distribute
across those.  Mostly that's a matter of carefully controlling the order
in which you specify those bricks in your "gluster volume create"
command.  The result should give you pretty good space utilization while
still protecting against a single machine failure.

Dividing up the space on a machine into several bricks can be a bit
tricky.  If there are several physical disks, that's great.  If you use
partitions, you will probably get poor performance as an even
distribution of work among bricks (something DHT tries to achieve) will
result in the disk heads thrashing between partitions.  If you use plain
old subdirectories you won't have that problem so much, but the
free-space reporting will be a bit inaccurate and could cause problems
when disks which are shared among several bricks become nearly full.
It's probably the best option overall, though, since it's easy to do and
will perform/behave pretty well the rest of the time.