[Samba] samba4 + drbd + ctdb + failover

[me at electronico.nc]

Le 06/07/2014 04:23, steve a écrit :
> Hi
> We've got drbd going between 2 nodes:)
>
> ATM there is un-partitioned space on each node but (we think) they are
> syncing OK. It looks as though it has synced the whole partition (2GB)
> from the primary node 1 to the other node:
>
> node 1
>   smb1:/home/steve # cat /proc/drbd
> version: 8.4.4 (api:1/proto:86-101)
> GIT-hash: 3c1f46cb19993f98b22fdf7e18958c21ad75176d build by SuSE Build
> Service
>
>   1: cs:Connected ro:Secondary/Secondary ds:UpToDate/UpToDate C r-----
>      ns:2096028 nr:0 dw:0 dr:2096028 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1
> wo:f oos:0
>
> node 2
> smb2:/home/steve # cat /proc/drbd
> version: 8.4.4 (api:1/proto:86-101)
> GIT-hash: 3c1f46cb19993f98b22fdf7e18958c21ad75176d build by SuSE Build
> Service
>
>   1: cs:Connected ro:Secondary/Secondary ds:UpToDate/UpToDate C r-----
>      ns:0 nr:2096028 dw:2096028 dr:0 al:0 bm:0 lo:0 pe:0 ua:0 ap:0 ep:1
> wo:f oos:0
>
> Question:
> What next?
> 0. Can any drbd guru give us a thumbs up so far?
I'm not a guru.
Here is what I've done with DRBD (ubuntu):
nano /etc/drbd.d/raid1.res
address are defined in /etc/network/interfaces and are assigned to the 
direct Gb NIC between smb1 and smb2 (for fast sync between HDs)
disk : your free partition on each server
->
resource raid1 {
  protocol C;
  startup { wfc-timeout 0; degr-wfc-timeout 120; }

disk { on-io-error detach; }
  on smb1.domain.lan {
   device /dev/drbd0;
   disk /dev/sda5;
   meta-disk internal;
   address 10.10.200.1:7788;
  }
  on smb2.domain.lan {
   device /dev/drbd0;
   disk /dev/sda5;
   meta-disk internal;
   address 10.10.200.2:7788;
  }
}

drbdadm create-md raid1
drbdadm up raid1
drbdadm attach raid1
drbdadm connect raid1
gives ->
"drbdsetup connect raid1 ipv4:10.10.200.1:7788 ipv4:10.10.200.2:7788 
--protocol=C' terminated with exit code 10"

only on smb1:
drbdadm primary --force raid1

> 1. Is it too late to format the partition(s)?
Something like (only on one server : the RAID is active)
mkfs.ext4 /dev/drbd0
(on smb1 and smb2) : create your mount point:
mkdir /media/my_mount_point
chown and chmod for your needs
> 1. Recommendation for file system to format the partition.
> 2. Do we need Pacemaker (or something) for the failover or does...
I've tested by making a NFS share to test HA :
on smb1 and smb2:
apt-get install nfs-kernel-server
nano /etc/exports
->
/media/my_mount_point 
10.10.20.0/24(rw,async,no_root_squash,no_subtree_check,fsid=1)

NFS should not be started as service but by Heartbeat, so:
update-rc.d -f nfs-common remove
update-rc.d -f nfs-kernel-server remove

apt-get install heartbeat
nano /etc/ha.d/ha.cf
->
autojoin none
# auto_failback on : smb1 is prefered as server, so Heartbeat will use 
it as often as possible
auto_failback on
keepalive 2
warntime 5
deadtime 10
initdead 20
bcast xenbr1
node smb1.domain.lan
node smb2/domain.lan
logfile /var/log/heartbeat-log
debugfile /var/log/heartbeat-debug

Heartbeat has to talk to servers using a password.
nano /etc/ha.d/authkeys
->
auth 3
3 md5 my_heartbeat_password

chmod 600 /etc/heartbeat/authkeys

Heartbeat actions configuration:
nano /etc/ha.d/haresources
eth1 : your LAN interface
10.10.20.1 : the virtual IP created, has to be a free IP on same smb1 
and smb2 LAN subnet
drbddisk::raid1 : the name of the ressource for the RAID array defined 
in /etc/drbd.d/raid1.res ( resource raid1 { ...)
->
smb1.domain.lan \
IPaddr::10.10.20.1/24/eth1 \
drbddisk::raid1 \
Filesystem::/dev/drbd0::/media/my_mount_point::ext4::nosuid,usrquota,noatime 
\
nfs-kernel-server

service heartbeat restart

on smb1:
ifconfig should show a eth1:0 interface with IP 10.10.20.1

You can test to access the NFS share from a client on LAN.
shutdown smb1 : NFS share is still accessible from the virtual IP : 
10.10.20.1, write something to NFS share.
power up smb1 : NFS share is still accessible from the virtual IP : 
10.10.20.1, read data on NFS share : they have well been written while 
smb2 was the NFS server.

important file to watch while testing : Heartbeat debug file : 
/var/log/heartbeat-debug
> 3. ...CTDB do that for us
>
> Thanks,
> Steve
>
>
I haven't had time yet to apply this the Samba File Server, but here is 
my working config.
Hope this helps.
Nicolas