sudarshan sridhar wrote: >> I'm not quite sure what you're asking here. Data, whether newly written or >> copy-on-write, goes to a newly allocated block, which may reside on any >> vdev, and will be spread across devices if using RAID.
> My exact doubt is, if COW is default behavior of ZFS then does COWd data > written to the same physical drive where the filesystem resides? Yes. > If so the physical device capacity should be more that what the file > system size is. Yes. > I mean in normal filesystem sinario, a partition with 1Gb with some some > filesystem (say ext2fs) is created, then use can save upto 1Gb data > under that. This is not true of any filesystem. There is always some overhead for meta data like indirect blocks, journals, superblocks, space maps etc. Some filesystems (eg UFS) have a fixed areas for meta data which limits the number of files and possible data, whereas others dynamically allocate the meta data (eg ZFS). The former is more predictable and the latter more flexible. > Is the same behavior with ZFS?. Because I feel since COW is default ZFS > require > 1Gb for one fileystem inorder to store COWed data. > > Please correct me if i am wrong. > > -sridhar > > ------------------------------------------------------------------------ > Never miss a thing. Make Yahoo your homepage. > <http://us.rd.yahoo.com/evt=51438/*http://www.yahoo.com/r/hs> > > > ------------------------------------------------------------------------ > > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
