Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
Hi,
I am new to drbd and have followed your website's HOWTO fairly closely,
but it appears when it comes to the last few steps as far as mounting
goes, there's a bit of vagueness -perhaps due to my own poor reading
comprehension, -but also, there are no command examples beyond "the
device should be usable" after you do the
drbdadm -- --overwrite-data-of-peer primary all
The "Migrating Resources" worked great, -and there's a reference to a mount command there, but that's a little further in.
My questions revolve around trying to understand the mounting process as it relates to replicating data on the secondary.
I list the exact steps I did, in an effort to get some answers to my questions below
-I truly thank you for any consideration/answers you may have.
----------------------
Install Centos 5
during install make a filesystem called /drbd-netblock and give it 1GB and it shows up as /dev/sda7
yum install drbd kmod-drbd
edit /etc/grub.conf to allow boot of the drbd kernel 2.6.18-8.1.6.el5 #1 SMP
reboot, the proper kernel should now be up.
modprobe drbd
umount /drbd-netblock filesystem so drbd can use it:
umount /drbd-netblock
edit /etc/drbd.conf /dev/sda7 is a 1GB filesystem I made during install called /drbd-netblock
#############
global { usage-count yes; }
common { syncer { rate 10M; } }
resource r0 {
protocol C;
net {
cram-hmac-alg sha1;
shared-secret "secretphrase";
}
on box1.mydomain.com {
device /dev/drbd1;
disk /dev/sda7;
address 192.168.1.2:7789;
meta-disk internal;
}
on box2.mydomain.com {
device /dev/drbd1;
disk /dev/sda7;
address 192.168.1.3:7789;
meta-disk internal;
}
}
##############
drbdadm create-md r0 # Is this done on just the primary or both? I did it on both.
drbdadm up all
you'll see:
[root@ ~]# ps ax | grep drbd
18063 ? S 0:00 [drbd1_worker]
18069 ? S 0:00 [drbd1_receiver]
18070 ? S 0:00 [drbd1_asender]
cat /proc/drbd will show both in secondary, as the drbd website howto shows, and you can promote a node to primary:
drbdadm -- --overwrite-data-of-peer primary all
[root@ ~]# cat /proc/drbd
version: 8.0.3 (api:86/proto:86)
SVN Revision: 2881 build by buildsvn at c5-x8664-build, 2007-05-23 14:07:33
1: cs:Connected st:Primary/Secondary ds:UpToDate/UpToDate C r---
ns:0 nr:0 dw:0 dr:0 al:0 bm:0 lo:0 pe:0 ua:0 ap:0
resync: used:0/31 hits:0 misses:0 starving:0 dirty:0 changed:0
My question is, when the howto says "The device is usable right away, go ahead and create a filesystem if you haven't already", what do they mean?
What are the following steps to get replication working?
I also made myself a 40GB partition called /replicated just in case I wanted to use that.
How does the "device" statement in the .conf file (device /dev/drbd1;) relate to any actual filesystem element? None right, it's just a name you give your netblock correct?
Is the "disk" statement (disk /dev/sda7;) referring to my 1GB filesystem space I created, that's what I should put right?
When you do the mount, are you doing "mount /dev/drbd1 /drbd-netblock1" or "mount /dev/drbd1 /replicated" ?
-krb