Operating System - OpenVMS
cancel
Showing results for 
Search instead for 
Did you mean: 

Max. files on disk

SOLVED
Go to solution
Fabian Kempers_1
Occasional Visitor

Max. files on disk

I would like to INIT a disk for a lot of file, but I can't seem to get more than 16711679 as maximum number of allowed files.
I've tries to increase/decrease clustersize, max headers, max files...

Is this an VMS limit?
7 REPLIES
Ian Miller.
Honored Contributor

Re: Max. files on disk

On what vesion of VMS? There where relevant changes in V7.2
____________________
Purely Personal Opinion
Uwe Zessin
Honored Contributor
Solution

Re: Max. files on disk

The file index number is a 24-bit value.

16711679 = 0.FE.FF.FF(16)
.
Fabian Kempers_1
Occasional Visitor

Re: Max. files on disk

OpenVMS 7.3-2
Daniel Fernandez Illan
Trusted Contributor

Re: Max. files on disk

Hi.

The maximum size you can specify for any volume is calculated as follows:

(volume size in blocks)/(cluster factor + 1)

You can modify cluster factor and increase max files.
Saludos.
Daniel.
John Gillings
Honored Contributor

Re: Max. files on disk

Fabian,

As you've discovered, the current ODS-2 and ODS-5 architectural limit on maximum files allowed on a simgle volume is 2^24-2^16-1 = 16711679

Engineering is aware that the limits of existing file systems is rapidly being overtaken by available technology. What they need is to know what customers need, with business cases to justify the engineering work to extend those limits that need extending (in other words, show them the money!).

In the mean time, you can make it appear there are many more files on a disk using search lists.

$ DEFINE MYDISK DISK1,DISK2,DISK3,DISK4

Make sure all disks have similar directory structures on them, and "rotate" the search list to distribute files.
A crucible of informative mistakes
Willem Grooters
Honored Contributor

Re: Max. files on disk

[quote]
In the mean time, you can make it appear there are many more files on a disk using search lists.

$ DEFINE MYDISK DISK1,DISK2,DISK3,DISK4

Make sure all disks have similar directory structures on them, and "rotate" the search list to distribute files.
[/quote]

We tried a similar trick once to "enlarge" a disk, but ran into trouble:

$ DEFINE MYDISK DISK1:[DIR1.DIR2.], DISK2:[DIR1.DIR2.]/TRANS=CONCEALED

and DIR3.DIR existed on each DISKn[DIR1.DIR2]; The contents of course was different (newest written on DISK1:[DIR1.DIR2.DIR3].
But when the application tried to access MYDISK:[DIR3]FILE.DAT (the file exists on DISK2:[DIR1.DIR2.DIR3]) RMS returned File not Found. Tracking down the reason, it as found that when reversing the searchlist, the problem was gone. The solution was to keep each base directory (DIR3, DIR4 etc, on the same level) on one disk only.
Willem Grooters
OpenVMS Developer & System Manager
Fabian Kempers_1
Occasional Visitor

Re: Max. files on disk

Thans all for the info.