jim (03/29/83)
SITUATION: Instrument Laboratories' micro computer "Pixel" is using a berkeley version of unix as an operating system. The pixel has a core memory of 1 meg and a winchester disk drive with a 40 meg capacity. The primary users of this system utilize an APL interpreter designed by "The Computer Company". In order to utilize APL, a predetermined amount of disk space must be created and assigned to an APL file. There are three such APL files with sizes 20,10 and 1 meg. APL users may share these files at the same time. The 20 meg file is the most commonly used file. PROBLEMS: 1. When more than one user uses APL the response time drastically changes.(from 5sec on up to minutes at times) 2. Backup is done to floppies. Using tar to backup is no problem unless any file being backed up is larger than one floppies storage capacity. In this case max capacity is 600k. Since the APL files are much greater than this amount using tar to back up APL files is not possible with the present size. A possible solution was to use split to reduce the large APL into several smaller files. The problem with this approach is the number of characters in a line (ie before end of line character) does not seem to be uniformly distributed. QUESTIONS: 1. Is there any way to increase response time when more than two users use APL. 2. What is involved in swapping APL users out of main mem. 3. If swapping is the primary cause of the slowed response time can a larger main memory help and can locking the process into main memory until finished help at the risk of causing a deadlock. 4. In the large APL file there exist many small files known to the APL interpreter. Can unix access these files in any way. Any discussion on this topic would be appreciated. If any one has any positive or negative comments I would like to hear from you. Please send mail to duke!ucf-cs!fau!jim