Sri Sudarsan wrote: > Regarding the question asked below namely "What happens when the free > space reported by ZFS isn't really the free space ?", is there an open > bug for this ? >
Not a bug. It is a result of the dynamic nature of ZFS. For example, when compression is enabled, we cannot tell in advance how well the data will compress, so how could we say how much space is available? Other items to consider: dynamically allocated, redundant, and compressed metadata; snapshots; multiple file systems in a pool, each with potentially different features including compression algorithms and data redundancy; clones; failed media; failed devices; etc. Kinda reminds me of the old question: how much stuff can you put into a hole in your pocket? -- richard > Thanks, > > Sri > Paul Kraus wrote: > >> On 1/15/08, Selim Daoud <[EMAIL PROTECTED]> wrote: >> >> >> >>> with zfs you can compress data on disk ...that is a grat advantage >>> when doing backup to disk >>> also, for DSSU you need to multiply number of filesystem (1 fs per >>> stu), the advantage of zfs is that you don't need to fix the size >>> of the fs upfront (the space is shared among all the fs) >>> >>> >> But ... NBU (at least version 6.0) attempts to estimate the >> size of the backup and make suer there is enough room on the DSSU to >> handle it. What happens when the free space reported by ZFS isn't >> really the free space ? >> >> We are using NBU DSSU against both UFS and ZFS (but not >> against VxFS) and have not noticed any FS related performance >> limitations. The clients and the network are all slower. >> >> >> > > _______________________________________________ > 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
