[Gluster-devel] Some gluster questions

[Anand Avati]

Reinis,
 replies inline.


> 1. Is it wise to let gluster do the local striping over disks/bricks?
>
> We wanted to use ZFS (as for its simplified management and nice features)
> but as there are issues installing OpenSolaris on HP DL380 (OS doesnt
> support install from USB (through ILO)) we ended up making a bunch of
> raid1
> (mirror) volumes and mounting them together with Gluster unify. But I am
> not
> sure which way would it be better - to make a large raid 6/10 volume (I
> personally dont like hardware raids which involve more than 6 disks) or
> bind
> the mirrors together with LVM and then export through Gluster or use it
> this
> way?


using LVM and re-exporting with GlusterFS should work well.

2. What is the correct way of adding a new local brick to (allready
> existing/filled) unify storage?
>
> I have defined a new brick volume and added it to unify subvolumes
> restarted
> both the client and server but the ALU scheduler still doesnt create any
> new
> files on the fresh brick
>
>
> The unify config:
>
> volume c1d1
>   type storage/posix
>   option directory /data/raw_c1d1
> end-volume
>
> ....
> ....
>
> volume unify
>   type cluster/unify
>   subvolumes c1d1 c1d2 c1d3 c1d4 c1d5 c1d6 c1d7 c1d8 c2d0 c2d1 c2d2 c2d3
> c2d4 c2d5 c2d6
>   option namespace ns
>   option scheduler alu
>   option alu.limits.min-free-disk  5%
>   option alu.limits.max-open-files 10000
>   option alu.order
> disk-usage:read-usage:write-usage:open-files-usage:disk-speed-usage
>   option alu.disk-usage.entry-threshold 10GB
>   option alu.disk-usage.exit-threshold  60MB
>   option alu.open-files-usage.entry-threshold 1024
>   option alu.open-files-usage.exit-threshold 32
>   option alu.stat-refresh.interval 10sec
> end-volume
>
>
> Could it be that the alu.disk-usage.entry-threshold  is too high? And the
> new volume doesnt get used until there is a 10Gb difference to others?
> (probably have to play arround first rather than asking questions)


This is correct. The new volume will get new files created when the
difference between it usage and the lowest other volume is < 60MB. You can
tune alu to suit your needs if they are different.

3. Is there another way to mount the volume locally not using TCP?


You could either completely avoid the client/server thing and directly have
the cluster and posix translators on the client side (under fuse), or you
could use transport/unix to avoid tcp on local machines.

We are transfering files from an older disk storage and setting up fuse
> kernel module and gluster client there is problematic. So we have mounted
> the exported gluster volume just back on the new storage server and
> transfering the files to the mountpoint (tar/ssh).
>
> Client config on the new box looks only like:
>
> volume remote
>   type protocol/client
>   option transport-type tcp/client
>   option remote-host 127.0.0.1
>   option remote-subvolume storage
> end-volume
>
>
> As I have seen people and in docs saying that you can load the translators
> anywhere - is it possible just to copy over all the volumes to client
> config
> (without the "protocol/server" volume) and "mount" the unify partition
> without the 'glusterfsd' at all?


Yes.

In this case scenario (mounting locally over TCP) should be the performance
> translators like io-threads / write-behind loaded also on client or is it
> enough to have them only on server (as they are the same box anyway)?
> Should the translators be on both client/server when there are different
> boxes?


you would ideally want write-behind on the client side and io-threads on he
server side. Both of them can be loaded in either places too.

avati