[Info-vax] Production VMS cluster hanging with lots of LEFO

[VAXman- at SendSpamHere.ORG]

In article <MPG.2424a6445c5a927e989687 at news.verizon.net>, John Santos <john at egh.com> writes:
>In article <e61cc3be-c732-4ed0-bff2-866c86e22314
>@e18g2000yqo.googlegroups.com>, heinvandenheuvel at gmail.com says...>=20
>> On Mar 13, 5:32=A0am, filip.debl... at proximus.net wrote:
>> > Greetings.
>> >
>> > Yesterday we had a massive incident on our most important VMS
>> > machines.
>>=20
>> > OS is VMS 8.3, we run DECNET over IP.
>>=20
>> > Fortunately I always keep some sessions open on by station (not part
>> > of the cluster), which were still working. The system was NOT down.
>>=20
>> > When looking at the first system, I immediately remarked a significant
>> > number of LEFO processes, most of them related to individual (DCL) user=
>s,
>
>[snip]
>
>> > - (not 100% sure of this) most of the LEFO processes where attempts=20
>to
>> > login, trying to run LOGINOUT.EXE (just another image ...)
>>=20
>> Handwaving here... wild speculation... when a process does not exist
>> yet and the first image still has to run but can not get to the disk
>> (that serialization lock) would it be Outswapped waiting for the disk,
>> considering it is not in yet?
>> I should crack open the internal book and remind myself of the states
>> in the life of a prcocess.  "in the  beginning...". But I don't have
>> time for that now.
>>=20
>
>To elaborate a little on this, since no one else has mentioned this
>explicitly...
>
>(Warning: this is all based on vague and ancient memory, and could
>be decades obsolete!)
>
>I think early one when the job controller (?) creates a new interactive
>process, it sets up a process header with appropriate values in the
>saved registers and it's memory mapped to a swapped-out copy of
>LOGINOUT.EXE (i.e. pointing to LOGINOUT's shared sections.)  Then
>when the swapper decides to swap it in, it loads the new processes'
>read-write data from LOGINOUT's writeable, copy-on-reference pages
>and the code & read-only data from LOGINOUT's shareable pages and
>off it goes.  During the time between it getting created and when
>the swapper swaps it in, it's in LEFO state.

COMO -> COM


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