Cluster size of large disks

[Paul Hansford]

>The application is a third party
>application that uses RMS and I've
>been told that the cluster size must
>be 51 or lower.

Is it that the application requires a cluster size of less than 51, or does the application have hardcoded limit on allocated file size.

I once had tp defrag system disk, using disk to disk image backup restore.

The target disk on my backup disk was very large (about 100gb) and I restored to original system disk with noinit.
Hence the cluster size was now large, (and minimum allocated size)

When I attempted to boot, I received the following: (or similar).

%DECnet-I-LOADED, network base image loaded, version = 05.12.00

%DECnet-W-NOOPEN, could not open SYS$SYSROOT:[SYSEXE]NET$CONFIG.DAT

I logged a call with Compaq, and was reliably informed that, The loader for Decnet base image tries to load net$config.dat, but has a hardcoded file size limit of, I think, 128 blocks. My net$config.dat was larger than 128 blocks. I believe this problem occured on OpenVMS 7.3-1, I don't know if it is still an issue, but my point being that even Compaq/HP designed OS code which could not handle files over a specific hardcoded size.

[Jeroen Hartgers_3]

The option set cluster size is available since open vms 7.2.

If you make the clustersize smaller you have to extent the indexf.sys manualy during the init, and you must probaly change your max files.

There is only 1 exception. If you restore a system disk you can not use backup/noinit because the disk wil not be a bootable disk after this action.

Or you could make partitions depents of you controler

[Uwe Zessin]

Forgive me, but all that doesn't make sense to me:

> The option set cluster size is available since open vms 7.2.

That's the first release to support a BITMAP.SYS > 255 blocks.

I have been able to use INITIALIZE/CLUSTER for _many_, _many_ releases, at least V4.x.

> If you make the clustersize smaller you have to extent the indexf.sys...

Why? The storage allocation bitmap is in BITMAP.SYS, not INDEXF.
Maximum files is the size of the file header allocation bitmap in INDEXF.SYS.

> There is only 1 exception.

Again, I don't understand that. BACKUP is supposed to properly update the boot block if you use BACKUP/IMAGE

[Karl Rohwedder]

BACKUP/NOINIT:

I am quite sure, that a copied systemdisks using BACKUP/IMAGE/NOINIT on order to change some relevant disk parameters and the new systemdisks booted perfectly (The /IMAGE is responsible for the correct backlinking... of VMS directories).

regards Kalle