iSCSI multipath

[frantek]

Hi,

I try to do a test setup with 2 Synology boxes with HA and iSCSI using multipath on my proxmox host. Now I've created a working iSCSI multipath device on the shell but is there an intended (GUI) way to add this device as a storage target? I'm able to add my singel iSCSI devices with LVM on to with the GUI but I found no way to do so with my multipath device. Can some one help?

TIA
Matthias

 

[tom]

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

 

[frantek]

thanks, I know this, but this ends where my question starts. Multipath works and I have a multipath device but is there an intended (GUI) way to add this device as a storage target? I'm able to add my singel iSCSI devices with LVM on to with the GUI but I found no way to do so with my multipath device. Do I have to set up LVM manually? How do I point the proxmox GUI to the new storage?

 

[tom]

You have a new storage? Multipath means you have just a second path to the SAME storage - creating redundancy and more performance.

And no, there is no extra GUI here as the default gui should just work.

and post the output of:

multipath -ll

 

[frantek]

You have a new storage?

Yes, besides the old local storage new Synology boxes connected by iSCSI.

Multipath means you have just a second path to the SAME storage - creating redundancy

Yes, but it's accessed by the multipath device and NOT by iSCSI directly ...

and more performance.

IMHO: No, as always only one path is being used. All other pathes are for redundancy only ... at least with all systems I use (Synology, DataCore, IBM SVC) (mainly with vmware)

And no, there is no extra GUI here as the default gui should just work.

AFAIK: No, the multipath device is not detected my the GUI and so the GUI can not be used to create a LVM setup on top.

and post the output of: multipath -ll

synology00 (36001405fb98d3aedfc4fd3d6edba71d3) dm-7 SYNOLOGY,iSCSI Storage
size=8.0T features='1 queue_if_no_path' hwhandler='0' wp=rw
`-+- policy='round-robin 0' prio=1 status=active
  |- 42:0:0:0 sdc 8:16 active ready running
  `- 43:0:0:0 sdd 8:32 active ready running

You can see that the name of the multipath device is "synology00".

This did the trick:

pvcreate /dev/mapper/synology00
vgcreate vgsyno00 /dev/mapper/synology00

Then I was able to choose "vgsyno00" in the GUI for creation of LVM storage.

For me this is solved now.

Next question

I'm doing all this because in near future I want to add a second host to get a cluster. Is shared iSCSI storage sufficient as storage for a cluster ?

TIA
Matthias