> 3. On illumos, ZFS never "gives back" blocks. Not by itself, but if one wants to release the nonzero blocks no longer referenced by zfs, it is possible to 'dd if=/dev/zero of=/uncompresseddataset/bigfile & sleep 5; rm /uncompresseddataset/bigfile' and so zero out the unused space. This can help when preparing vm images for redistribution or as golden templates, full backups, etc. (i.e. when compression or image compaction will shave off the zeroed ranges of the disk image). Generally should be done on quiesced systems ready to shut down (i.e. not when you have servers running that would complain about no free space). Also, this is a nice moment to turn off swap and zero out its dataset, if it was ever really used.
Jim -- Typos courtesy of K-9 Mail on my Samsung Android ------------------------------------------- illumos-discuss Archives: https://www.listbox.com/member/archive/182180/=now RSS Feed: https://www.listbox.com/member/archive/rss/182180/21175430-2e6923be Modify Your Subscription: https://www.listbox.com/member/?member_id=21175430&id_secret=21175430-6a77cda4 Powered by Listbox: http://www.listbox.com
