From:	HENRY::IN%"SYSTEM%crnlns.bitnet%wiscvm.wisc.edu%kl.sri.COM%relay.cs.net@RCA.COM" 26-APR-1987 17:36
To:	info-vax@kl.sri.com
Subj:	re: ACP error HEADERFULL message ?

Anil,

As I understand it, the HEADERFULL message is a known problem with
VMS 4.5 and earlier. It may or may not be fixed in 4.6.

It is telling you that it can't extend the index file on the volume
for some reason. I think one cause may be that the disk structure
is too badly fragmented. At any rate, you will have to do a full
Backup and restore of the disk.

My solution is to initialize our user disk with a preallocated
index file that is large enough for all the files that will be created.
Also, you must not let a Backup "image mode restore" initialize the disks
itself. (Specify /NOINITIALIZE to Backup when you start the restore.)

This also gets around the problem that some sites have seen where
two cluster members try to extend the index file simultaneously
and both manage to do it, creating two incompatible extensions.
This bug is also reported to be under investigation.

Our user disks typically have about 30,000 files on each.
The following command preallocates 40,000 file headers:

 $ INIT HSC000$DUA5: SCRATCH_DISK /HEADERS=40000/CLUSTER=8/EXTENSION=32

I hope this helps.

Selden E. Ball, Jr.
(Wilson Lab's network and system manager)

Cornell University                 NYNEX: +1-607-255-0688
Laboratory of Nuclear Studies     BITNET: SYSTEM@CRNLNS
Wilson Synchrotron Lab              ARPA: SYSTEM%CRNLNS.BITNET@WISCVM.WISC.EDU
Judd Falls & Dryden Road          PHYSnet/HEPnet/SPAN:
Ithaca, NY, USA  14853             LNS61::SYSTEM = 44283::SYSTEM (node 43.251)
