tn03@uafhcx.uucp (Tn3270 access) (11/12/90)
I have been asked to design a program to reorganize the file system under HP-UX because there is concern that performance may suffer if data gets too far scattered across the disk? Is this true. I have heard that this is taken care of by the operating system. Let me know. Thanks in advance. James
paul@prcrs.UUCP (Paul Hite) (11/14/90)
In article <5526@uafhp.uark.edu>, tn03@uafhcx.uucp (Tn3270 access) writes: > > I have been asked to design a program to reorganize the file system under HP-UX > because there is concern that performance may suffer if data gets too far > scattered across the disk? Is this true. > HP-UX (in it's current incarnation on the 300's and 800's) uses a modified version of the Berkeley file system. In theory the cylinder group stuff tends to keep the data localized and thus periodic re-orgs are not needed. If a file system is allowed to become too full, the last files written can be scattered. There is a min-free parameter set to 10%. If this is respected, the file system can't become too full. Anyway that what I have read and we have never re-orged our file systems. If re-orging a file system was necessary, I probably wouldn't trust a program that attempted this "in place". Rather I would just dump the files to tape, rebuild the file system, and restore the files. If I did use an "in-place" type program, I would still want a backup. So the re-org program would have to be faster than reloading the files to be a win. A program to reorg a file system is a job for a real guru. I doubt that either of us has any business attempting such a feat. But if you do pursue this, you may want to post any further questions to comp.sys.hp. That's where the HP-UX gurus hang out. Paul Hite PRC Realty Systems McLean,Va uunet!prcrs!paul (703) 556-2243 You can't tell which way the train went by studying its tracks.