[Info-vax] INIT/LIMIT, SET VOLUME/LIMIT, /MAXIMUM_FILES, /CLUSTER_SIZE

[Phillip Helbig---undress to reply]

In article <ijooa2$2q2$1 at online.de>, helbig at astro.multiCLOTHESvax.de
(Phillip Helbig---undress to reply) writes: 

> Over the past few days, I have initialised various disks, all but one
> with a cluster size of 16 (the exception has 128).  They are either 4.3
> or 8.6 GB in size.  I compared the value of maximum files as reported by
> SHOW DEVICE with that calculated from the formula given in
> HELP/INIT/MAXIMUM_FILES:
> 
> $ WRITE SYS$OUTPUT f$getdvi(x,"maxblock")/((f$getdvi(x,"cluster")+1)*2), -
>    "   ", f$getdvi(x,"maxfiles") 
> 
> In some cases they agree; so far, so good.  In other cases, the second 
> value is equal to one more than twice the first value.
> 
> First question: why the difference?
> 
> Second question: could there be some (undocumented) difference between 
> INIT/LIMIT and SET VOLUME/LIMIT?
> 
> Third question: According to help, the highest possible value of
> MAXIMUM_FILES is twice the default value; why do I get, in some cases, 
> one more?  (I didn't use the undocumented INIT/SPINAL_TAP.)
> 
> Note that I never used the /MAXIMUM_FILES qualifier.

Here's some more information: identical disks, with direct connections
(BA356) to two different nodes.  Below is the output of this procedure:

$  MOUNT/OVER=ID 'P1'
$  PIPE SHOW DEVICE/FUL 'P1' | SEA SYS$PIPE -
    label,"Total blocks","logical volume","cluster size","maximum files",high
$  wso f$getdvi(P1,"maxblock")/((f$getdvi(P1,"cluster")+1)*2), "   ", -
    f$getdvi(P1,"maxfiles")
$  wso "label: ", f$getdvi(p1,"logvolnam")
$  wso "total: ", f$getdvi(p1,"maxblock")
$  wso "cluster: ", f$getdvi(p1,"cluster")
$  wso "maxfiles: ", f$getdvi(p1,"maxfiles")
$  DISMOUNT 'P1'
$  EXIT

%MOUNT-I-MOUNTED, USER mounted on _$110$DKB400: (JANDER)
    Total blocks            17773524    Sectors per track                   168
    Logical Volume Size     17773524    Expansion Size Limit         2147475456
    Volume label              "USER"    Relative volume number                0
    Cluster size                  16    Transaction count                     1
    Free blocks             17336560    Maximum files allowed          
16711679
522750   16711679
label: DISK$USER
total: 17773524
cluster: 16
maxfiles: 16711679

%MOUNT-I-MOUNTED, USER mounted on _$150$DKB400: (LEEBIG)
    Total blocks            17773524    Sectors per track                   168
    Logical Volume Size     17773524    Expansion Size Limit         2147475456
    Volume label              "USER"    Relative volume number                0
    Cluster size                  16    Transaction count                     1
    Free blocks             17340512    Maximum files allowed            522750
522750   522750
label: DISK$USER
total: 17773524
cluster: 16
maxfiles: 522750

Note that the first disk is showing a too high value for maximum
files. 

Also, the freeblock count is different, while I would expect it to be
the same for a fresh initialisation.  Third, "wrong" maxfiles value in
this example (first disk above) is much higher than in the other
examples, where it is always one more than twice the default.

OK, will do a fresh initialisation of both disks.

$ init/sys/head=400000/nohigh/limit/clust=16

OK, first disk looks just the same as before.

INIT doesn't work on the second disk now, maybe because there is too 
much activity on the bus.  Will try again later.