MC wrote: > To expand on this: > >> The recommended use of whole disks is for drives with volatile >> write caches where ZFS will enable the cache if it owns the whole disk. > > Does ZFS really never use disk cache when working with a disk slice?
This question doesn't make sense. ZFS doesn't know anything about the disk's cache. But if ZFS has full control over the disk, then it will attempt to enable the disk's nonvolatile cache. > Is there any way to force it to use the disk cache? ZFS doesn't know anything about the disk's cache. But it will try to issue the flush cache commands as needed. To try to preempt the next question, some disks allow you to turn off the nonvolatile write cache. Some don't. Some disks allow you to enable or disable the nonvolatile write cache via the format(1m) command in expert mode. Some don't. AFAIK, nobody has a list of these, so you might try it. Caveat: do not enable nonvolatile write cache for UFS. -- richard _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
