[pve-devel] iscsi, some hang : pvestatd always do iscsi_session_rescan

Dietmar Maurer dietmar at proxmox.com
Wed May 16 06:59:29 CEST 2012

Hi Alexandre,

> The main advatange with many luns, is that multipath, it's a lot faster as by
> exemple with 300luns+2 path, I got 600 devices to monitor on each host, and
> multipathd use a lot of cpu.
> Also system can be unresponsive in case of iscsi problems with so much
> devices hanging.
> And finaly, remove scsi luns if really a pain for the moment, as if you remove
> a lun in your scan, you need to remove it on each host manually on each
> path. With this method, device is remove at vm stop :)
> What do you think about it ?

Is a bit difficult to understand, because I do not have that problem. The suggested way
is to use LVM on top of iSCSI, and that avoid the whole problem AFAIK.

Anyways, the whole thing looks like a workaround, and it is maybe easier to fix the cause of the problem (iscsid)?
Form what I see you want:

- do not create any devices at iscsi login
- do not create devices when scanning for luns (any other way to list luns?)
- avtivate/deactivate LUNs selectively

Because we want to activate/deactivate devices selectively. You already asked the iscsi developers about their opinion?

- Dietmar

More information about the pve-devel mailing list