[Info-vax] Cluster hang on node reboot

[Kerry Main]

> -----Original Message-----
> From: Info-vax [mailto:info-vax-bounces at info-vax.com] On Behalf Of
> Martin Vorlaender via Info-vax
> Sent: 16-Jun-16 7:28 AM
> To: info-vax at info-vax.com
> Cc: Martin Vorlaender <martinvorlaender at gmail.com>
> Subject: [New Info-vax] Cluster hang on node reboot
> 
> Hi all!
> 
> I have experienced an issue with a customer's VMS cluster I have no
> explanation for.
> The cluster consists of 2 rx2800 i2 + 1 DS25 for the quorum. The rx's
HBVS
> disks are
> provided by 2 3Pars. The rx's are running VMS V8.4 + UPDATE V11.0 +
> FIBRE_SCSI V9.0 .
> 
> When one of the rx2800 reboots and re-joins the cluster, there is a 2
> minute hang
> of the entire cluster. I ran a TCP/IP ping from the remaining rx2800
to
> another
> system during this time which didn't lose a packet, and another DCL
> session still
> took commands, but a simple SHOW DEVICE D issued during that time
> hangs, and comes
> back with its expected output afterwards. There were no OPCOM
> messages during that
> period (the last one issued before it being the cluster transition
> completion).
> 
> I'd suspect that access to the (shadowed) common system disk is
> blocked for those
> 2 minutes. I had minimerge enabled and DOSD parameters set up, but
> without really
> moving the dump files off the system disk (i.e. DUMPFILE_DEVICE set to
> the DGA devices
> of the system disk shadow set). I have switched it off since then, but
> didn't have
> a chance to test whether that was the reason for the hang.
> 
> Any ideas?
> 
> TIA,
> Martin

Availability Manager is a good cluster management tool to have in place 
for Issues like this. Small charge on Integrity, free for Alpha. 

Regards,

Kerry Main
Kerry dot main at starkgaming dot com