Hi everyone,
I have some questions for the experts regarding a SAN
configuration.
Configuration:
FAS3020c MetroCluster (2 sites, 16km distance)
2 FC-Switches on each site, each connected via
ISL’s to the other location.
1 RHEL ES4 U5 Host on each site with a 4GB QLogic
Dual Port HBA.
Each FC-Port on each Host is connected to one of the
switches
FCP enabled and the cf mode is single image
Snapdrive for Linux on both Hosts.
Following situation:
Snapdrive for Linux currently does not support
DM-Multipathing on RedHat Linux.
We have an open case with Netapp and they are working
on the issue to support mulipathing (planned for Q1/08)
When I started I setup everything for multipathing
because we thought the support for it would be released earlier.
I zoned the switches…
Zoning:
switch1 zone1: 0b(filer1)+0b(filer2)+port0(host1)
switch1 zone2: 0b(filer1)+0b(filer2)+port1(host2)
switch2 zone1: 0d(filer1)+0d(filer2)+port1(host1)
switch2 zone2: 0d(filer1)+0d(filer2)+port0(host2)
On the host I implemented DM-MP and use the
mpath-Device’s to access the LUN’s on the cluster.
Each mpath-Device consists of 4 sdx-Devices(=the 4
paths to the LUN).
Example:
mpath0 (360a98000433464706334455142706e33)
[size=100 MB][features="1
queue_if_no_path"][hwhandler="0"]
\_ round-robin 0 [enabled]
\_ 3:0:1:0 sdd 8:48 [active][ready]
\_ 4:0:1:0 sdf 8:80 [active][ready]
\_ round-robin 0 [enabled]
\_ 3:0:0:0 sdc 8:32 [active][ready]
\_ 4:0:0:0 sde 8:64 [active][ready]
This is working fine. The customer already installed
his Oracle RAC on the LUN’s/mpath-Device’s which where presented to
the host’s.
And here my problem:
The customer can not wait until Q1/08 when Snapdrive
for Linux supports multipathing on RHEL and I have to redesign the SAN to a
single path configuration so SnapDrive is working and supported.
My questions:
Can I just use the sdx-Devices on the linux
host’s and leave the zoning and multipathing as it is?
Will the cluster failover then work correctly?
Or should I deactive multipathing on the hosts and just
zone one hba port to one filer fc port and use that sdx-Device?
I will have to implement multipathing for sure later
when it is supported with linux and snapdrive so I prefer minimum or no changes
to the current configuration J
Has anyone experience with such a problem/configuration?
Thankful for any tips & hints!
Best regards,
Alexander
--
Alexander Schalek, Technical Services /
IT-Infrastruktur
Bacher Systems EDV GmbH
FN 54202i, Handelsgericht Wien
Clemens-Holzmeister-Strasse 4
A-1100 Wien,
phone: +43 (1) 60 126-34 | fax: +43 (1) 60 126-4
e-mail: as@bacher.at | web: www.bacher.at