[PVE-User] HP MSA 1040 SAN, multipath and LVM...

[Marco Gaiarin]

Greetings to all! I'm jumped by some week in the Proxmox world, i'm
still experimenting a bit doing some test P2V migration, so, excuse me
if ask dumb question...


As stated in subject, my system (for now two nodes, HP ProLiant ML150
Gen9) use the SAN HP MSA 1040; that SAN have two controller, with two
network port (gigabit ethernet, in mine) per controller.
To provide redundancy and more bandwidth, i use 'multipath', configured
following the wiki:

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

First note:that wiki page i think misses a note: you have to create a
LVM on the iSCSI target (creating it before adding to multipath conf)
or doing by hand, as found here (#12):

https://forum.proxmox.com/threads/multipath-iscsi.2808/


All works like a charm, but i have two little trouble, and i've not
found in wiki info about.

1) probably not a proxmox issue, but... if i reboot a node, sometime
multipath does not setup correctly. A simple 'systemctl restart
multipath' fix the issue but... i think there's some parameter i can
tweak to behave correctly.
In the meantime, i've put the restart on rc.local.

2) i've not found a way to setup correctly the volume to accept .qcow
disks, eg i've followed:

http://pve.proxmox.com/wiki/Storage_Model#LVM_Groups_with_Network_Backing

but the volumes created accept only RAW disk format.

There's some way to make a iSCSI target accept other format?


Thanks.

[Michael Rasmussen]

On Wed, 4 May 2016 16:22:06 +0200

Post by Marco Gaiarin
2) i've not found a way to setup correctly the volume to accept .qcow
http://pve.proxmox.com/wiki/Storage_Model#LVM_Groups_with_Network_Backing
but the volumes created accept only RAW disk format.
There's some way to make a iSCSI target accept other format?

qcow format requires a filesystem below and since iscsi is a raw block
device you cannot create qcow files directly on the target. If you want
be to able to make both raw and qcow disk formats your option is to
export two targets from your san. One target is used for lvm-raw disks
and on the other target you create a filesystem for qcow based disks.
Only downside to this is that you cannot use such a disk for shared
storage (the storage will be treated as a local disk on the proxmox
host).
--
Hilsen/Regards
Michael Rasmussen

Get my public GnuPG keys:
michael <at> rasmussen <dot> cc
http://pgp.mit.edu:11371/pks/lookup?op=get&search=0xD3C9A00E
mir <at> datanom <dot> net
http://pgp.mit.edu:11371/pks/lookup?op=get&search=0xE501F51C
mir <at> miras <dot> org
http://pgp.mit.edu:11371/pks/lookup?op=get&search=0xE3E80917
--------------------------------------------------------------
/usr/games/fortune -es says:
A father doesn't destroy his children.
-- Lt. Carolyn Palamas, "Who Mourns for Adonais?",
stardate 3468.1.

[Michael Rasmussen]

On Wed, 4 May 2016 16:22:06 +0200

Post by Marco Gaiarin
2) i've not found a way to setup correctly the volume to accept .qcow
http://pve.proxmox.com/wiki/Storage_Model#LVM_Groups_with_Network_Backing
but the volumes created accept only RAW disk format.
There's some way to make a iSCSI target accept other format?

qcow format requires a filesystem below and since iscsi is a raw block
device you cannot create qcow files directly on the target. If you want
be to able to make both raw and qcow disk formats your option is to
export two targets from your san. One target is used for lvm-raw disks
and on the other target you create a filesystem for qcow based disks.
Only downside to this is that you cannot use such a disk for shared
storage (the storage will be treated as a local disk on the proxmox
host).

- --
Hilsen/Regards
Michael Rasmussen

Get my public GnuPG keys:
michael <at> rasmussen <dot> cc
http://pgp.mit.edu:11371/pks/lookup?op=get&search=0xD3C9A00E
mir <at> datanom <dot> net
http://pgp.mit.edu:11371/pks/lookup?op=get&search=0xE501F51C
mir <at> miras <dot> org
http://pgp.mit.edu:11371/pks/lookup?op=get&search=0xE3E80917
- --------------------------------------------------------------
/usr/games/fortune -es says:
A father doesn't destroy his children.
-- Lt. Carolyn Palamas, "Who Mourns for Adonais?",
stardate 3468.1.

[Marco Gaiarin]

Mandi! Michael Rasmussen
In chel di` si favelave...

Post by Michael Rasmussen
qcow format requires a filesystem below and since iscsi is a raw block
device you cannot create qcow files directly on the target. If you want
be to able to make both raw and qcow disk formats your option is to
export two targets from your san. One target is used for lvm-raw disks
and on the other target you create a filesystem for qcow based disks.
Only downside to this is that you cannot use such a disk for shared
storage (the storage will be treated as a local disk on the proxmox
host).

Ok, i've reread the wiki and other docs and now, with this note, all is
clear. Probably i've misunderstood something, and i get fooled.

Now it is clear and coherent.


Many thanks!!!