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Conference ssdevo::hsj40_product

Title:HSJ30/40 Product Conference
Moderator:SSDEVO::EDMONDS
Created:Tue Jul 13 1993
Last Modified:Fri Jun 06 1997
Last Successful Update:Fri Jun 06 1997
Number of topics:1264
Total number of notes:4958

1214.0. "NOSUCHDEV when mount disk during boot" by HGOVC::CHIKAICHEUNG () Mon Feb 24 1997 23:48

	One of our customer got 3 alpha 8000, one use XMI CI adapter while 
the other two use PCI CI adapter and they all run VMS V6.2-1H3. Most of the 
disks are under HSJ40 controller.

	For those 8000 with PCI CI adapter, everything works fine but for 
the one with XMI CI adapter, when mounting disks under HSJ40 controller in 
the startup process, some of the disks will not be available during mount 
and the mount command will fail. Those disks that are unavailable during 
mount are not always the same, sometimes under this channel and sometimes 
under the other channels. Customer had moved the mount commands to the last 
minute of the bootup procedure but still got the error although the chance 
is much less.

	This is really a timing problem for the system to recognise all the 
disk devices but our customer would like to know what exact amount of delay 
should they add. They don't just want to have a trial and error testing as 
the machines are for production and the availability of all the disks 
before starting application is a major concern for them.

	Could anyone help to provide some data on this matter or any 
pointer that I can look for?

thanks & regards,
ck
T.RTitleUserPersonal
Name		DateLines
1214.1OSOV03::KAGEYAMATrust, but VerifyTue Feb 25 1997 21:195
This is not a direct answer to your question, but SYS$EXAMPLES:MSCPMOUNT.COM
might help your customer.

- Kazunori
1214.2HGOVC::CHIKAICHEUNGWed Feb 26 1997 03:1610
    The availability of all disks mounted is important to our customer and
    they can write some procedure to wait for the disk's availability but
    what they worry about is if some disk really break down, then the wait
    command procedure will wait for indefinitly until the disk is ready
    again. So if there is a more reliable time to wait, they can just wait
    for that amount of time before mount.
    
    thanks & regards,
    ck
1214.3"WAIT" did it for usTOPTEN::KELLERWed Feb 26 1997 21:0413
    We had this problem about 4 years ago on some VAX 7600's with
    "many" CIXCD's and about 400 RA's spread out over 24 HSC's.  We just
    inserted a "wait" instruction for several seconds (don't remember how
    many and that can vary from system to system) and that resolved that
    problem.  I think it was no more than 10 seconds or so.  The customer
    did later on write a program to check mounting disks, but not for this
    problem.  He did not want to start any application stuff up until all 
    mounting was done.  For speed purposes we were starting several batch
    jobs which did all our mounting.  Today, this allows us to mount well
    over 500 spindles in a very short period of time, all CIXCD based with 
    the same HSC's and a dozen HSJ's.  
    
    Larry
1214.4HGOVC::CHIKAICHEUNGFri Feb 28 1997 03:207
    How about if one of those disk really dead, then the mount process will
    wait indefinitly for it when the system is booting? That's what the
    customer don't want.
    
    regards,
    ck
1214.5it depends on the situation.TOPTEN::KELLERMon Mar 03 1997 09:1515
    In our case there are operators who monitor such things and will know
    that the applications did not come up and will get in touch with the 
    appropriate people, and they will know that within 15 minutes or so. 
    It will depend upon the circumstances, all things taken into account. 
    In our case if things are not correct, they do not want to come up
    until someone checks things out.  The potential for damage would be
    higher if some databases are not available then if they just came up
    haphazardly and waited until someone says we have a problem here.  The
    system manager along with the users or marketing people or whoever, de-
    pending on the application and the impact of the problem have to make
    that determination.  If you have a good system manager who knows the 
    application well and the impact of the situation can program
    accordingly.
    
    Larry