Krishna Srinivas wrote:
Hi All,
Maybe this piece of information will benifit others too, in case you
are confused about using -n option during glusterfs mount.
---------- Forwarded message ----------
From: Krishna Srinivas <krishna@xxxxxxxxxxxxx>
Date: Jul 3, 2007 9:30 PM
Subject: Re: Gerry Reno .vol files and scripts
To: Gerry Reno <greno@xxxxxxxxxxx>
Gerry you are not getting it ....
See, -n option should not be used in normal cases, its used normally
during debugging, say when you want to override the topmost translator.
If you really want to use -n option, just give -n afr which is the
name of
the afr volume in your spec. which is same as not using -n option.
Internally, when glusterfs process is started, it arranges the
xaltors like this:
------>client0
fuse --->afr ---->client1
----->client2
------>client3
i.e fuse talks to afr, and afr talks to client0, client1, client2,
client3
However if you give "-n client0", the arrangement will be like this:
fuse--------------->client0
afr ---->client1
----->client2
------>client3
So fuse will directly talk to client0, so afr does not even come into
picture, so no files are replicated.
I dont know if the diagrams will reach you in a proper formatted way.
Come to IRC if it does not make sense.
Krishna
On 7/3/07, Gerry Reno < greno@xxxxxxxxxxx> wrote:
>> > Krishna Srinivas wrote:
>> >>>>>>>> Yes '-L DEBUG' is declared.
>> >>>>>>>> glusterfs -l /var/log/glusterfs.log -L DEBUG --spec-file
>> >>>>>>>> /usr/local/etc/glusterfs/test-client.vol -n client0
>> >>>>>>>> /mnt/glusterfs0/
>> >>>>>>>>
>> >>>>>>>>
>> >>>>>>>>
>> >>>>> you should not give -n client0 here, it will override the afr
>> >>>>> translator.
>> >>>>> Hence you are not seeing any replication!
>> >>>>>
>> >>>>>
Krishna,
For the sake of completeness I'm also going to post my response to the
above:
Krishna,
Now that you show this it makes some sense. But to just see options to
glusterfs which says use '-n' to select which volume, well that does not
say anything to me about the fact that this breaks AFR. You are so
close to the code that for you this is obvious but for those not close
to the code this is not obvious. And if there is some type of
incompatibility between '-n' and AFR then this needs to be documented
and also warning messages need to be present during it's use.
Gerry
