Multipath management

[ghido]

Hi all,
i'm starting to use proxmox for testing the system before using it in a production system.
I'm using a server IBM x3650 M3 with FC dual controller connected with an IBM DS3400 Storage.
I want to use multipath for manage the failover of FC card.
what's the better way for do this implementation?
My idea is:
- install multipath-tool and multipath-tool-boot
- create the multipath.conf
- create lvm group on the mapper
- use lvm in proxmox


But i have some problem with multipath:
- a lot of I/O error on all device connected with the multipath sdd, sde, sdf, sdg
- multipath doesn't create a table map.
Some can suggest me some trick or another way for implemented this project?
Thanks a lot

Ghido

 

[charnov]

http://pve.proxmox.com/wiki/ISCSI_Multipath

 

[ghido]

Yes, but the howto is talking about ISCSI and I need to use FC, is the same procedure?

 

[charnov]

Not really sure... hmm. I'm a little short on FC knowledge with dual port HBA's. I think you need to set the failover mode in the FC driver and on the FC Switch or FC-SAN. Beyond that, I don't know if it's better for active/active or active/passive but I don't think multipath comes into it... need a FC expert here... sorry.

 

[vcp_ai]

But i have some problem with multipath:
- a lot of I/O error on all device connected with the multipath sdd, sde, sdf, sdg
- multipath doesn't create a table map.
Some can suggest me some trick or another way for implemented this project?
Thanks a lot

Ghido

Not sure if it is same problem, but I installed multipath, I had lot of problems with LVM commads (pvscan, lvdisplay, pvdisplay ) not working against passive units. (I.E. the unit that is not active on multipath).

To prevent that, you must exclude this units on /etc/lvm/lvm.conf with a 'filter'

Mi config :

# lsscsi
[0:0:0:0]    storage HP       P410i            3.50  -
[0:0:0:1]    disk    HP       LOGICAL VOLUME   3.50  /dev/sda
[1:0:0:0]    disk    DGC      LUNZ             0429  /dev/sdb
[1:0:0:2]    disk    DGC      RAID 5           0429  /dev/sdd
[2:0:0:0]    disk    DGC      LUNZ             0429  /dev/sdc
[2:0:0:2]    disk    DGC      RAID 5           0429  /dev/sde
#

I.E. disks /dev/sdd and /dev/sde are the units used by multipath

#multipath -l
XXXXXXXXXXXX(xxxxxxxxxxxxxxxxxxxxxxxxxx) dm-6 DGC     ,RAID 5
[size=100G][features=1 queue_if_no_path][hwhandler=1 emc]
\_ round-robin 0 [prio=0][active]
 \_ 1:0:0:2 sdd 8:48  [active][undef]
\_ round-robin 0 [prio=0][enabled]
 \_ 2:0:0:2 sde 8:64  [active][undef]
#

So you must exclude these units, editing /etc/lvm/lvm.conf . Look for filter ...

    # By default we accept every block device:
    # filter = [ "a/.*/"  ]                             <<  This was the original    and REPLACED with 
    filter = [  "r|/dev/sdd|", "r|/dev/sde|" ]

Hope it helps ....

 

[ghido]

thank you very much!
I set the filter in lvm and i follow the howto adapted to FC.