On Wed, 15 Apr 2009 09:54:44 -0400, Mark Jacobs <[email protected]> wrote:
>Mark Zelden wrote: >> On Wed, 15 Apr 2009 10:50:37 +0200, R.S. <[email protected]> wrote: >> >> >>> By the way: is there any procedure to defrag HFS/ZFS ? >>> I mean some process similar to PDS compress or KSDS reorg. >>> Is there any need to do it? >>> How to measure it? >>> >>> Further explanation: I'm not talking about defragmentation o f volume >>> containing HFS dataset, rather about defragmentation of the dataset content. >>> >>> -- >>> >> >> >> For HFS, it shouldn't be needed - similar to PDSE (assuming the files within >> the HFS aren't in use). Pages from deleted files or index pages are >> can be reused after the last connection to the file has been terminated. >> See similr past discussions on PDSE (especially in the LNKLST) in the >> archives. >> >> For zFS, space is reused also. I suggest you read the zFS admin guide and >> in particular the section on zFS disk space allocation that describes how >> system and user areas are allocated in the aggregate. >> >> Do you have a reason or evidence that makes you think you need to >> defrag / reorg an HFS or zFS? >> >> Mark >> -- >> Mark Zelden >> Sr. Software and Systems Architect - z/OS Team Lead >> Zurich North America / Farmers Insurance Group - ZFUS G-ITO >> mailto:[email protected] >> z/OS Systems Programming expert at http://expertanswercenter.techtarget.com/ >> Mark's MVS Utilities: http://home.flash.net/~mzelden/mvsutil.html >> >> >We have a problem when a hfs/zfs grows to a huge size and since partial >release doesn't work on these files to recover the allocated but unused >space we have to perform a copy process to a new dataset. > Yes, secondary extents won't be freed. But the space within those extents should be reusable once allocated. If this happens all the time, then what is the point of freeing it? Allocate it larger with no secondary... Mark -- Mark Zelden Sr. Software and Systems Architect - z/OS Team Lead Zurich North America / Farmers Insurance Group - ZFUS G-ITO mailto:[email protected] z/OS Systems Programming expert at http://expertanswercenter.techtarget.com/ Mark's MVS Utilities: http://home.flash.net/~mzelden/mvsutil.html ---------------------------------------------------------------------- For IBM-MAIN subscribe / signoff / archive access instructions, send email to [email protected] with the message: GET IBM-MAIN INFO Search the archives at http://bama.ua.edu/archives/ibm-main.html
