[EMAIL PROTECTED] wrote on 01/15/2008 03:04:15 PM: > > 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. > > > > > 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 ? >
I do not believe it is a ZFS bug. Consider: The NetBackup server scans a backup client system, It determines it will need 600gb of disk space on the disk store. It stats the zfs volume and sees there is 700 gb free (enough for the backup) Starts writing 600gb over multiple hours. in the meantime, 500gb is used elsewhere in the pool. NetBackup Fails differently that on vmfs+vxvm in this case? Isn't it NetBackups issue to make sure that it has reserved diskspace or at least checks for space _as_ it writes? -Wade _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
