Pagefile size limitation? VAX VMS v6.2

[Art Wiens]

I created and installed a 2M block pagefile and a 2M block swapfile for a VAX. I see an oddity when I do a SHOW MEMORY (see atachment). It seems like it's split the pagefile in half. Is this a "problem"?

[Ian Miller. · Accepted solution]

because a page file virtual block number is limited in size (to 20 bits) then a pagefile can appear to be split as multiple pagefile entries are used to map the file. Not a problem really unless you run into the limit on how many pagefile you can have installed (PAGFILCNT)

[John Gillings]

Note that this is only a limit on VAX. As of OpenVMS Alpha V6.1, the only real limits on pagefile space are your storage budget.

[Veli Körkkö]

well, there is some sort of limit on Alpha too. Or used to be before V7.3. Just like on VAX the pagefile gets split when it is bigger than some
1048576 blocks, the magig number on Alpha would be 16*1048576, i.e. 16777216 blocks. At least that would be the before VMS V7.3 (alpha).

Installing a new GS160 with 24GB memory, the initial setup was whole system one instance and autogen tuned pagefile some 10Gb size. Next boot SHOW MEMORY showed something like 8GB and rest pagefiles with same name.

Would VMS treat these "two separate pagefiles"
as really different pagefiles? If so, having "one large" and "one small" could be very bad.

_veli