On Jan 11, 2010, at 4:42 PM, Daniel Carosone wrote: > I have a netbook with a small internal ssd as rpool. I have an > external usb HDD with much larger storage, as a separate pool, which > is sometimes attached to the netbook. > > I created a zvol on the external pool, the same size as the internal > ssd, and attached it as a mirror to rpool for backup. I don't care so > much about it not being bootable, as long as I can read whatever data > I might need in case of failure or loss.
IMHO, a split mirror is not as good as a decent backup :-) At one time, Tim Foster's scripts had a backup feature where you could specify a backup flag on a file system which would automatically backup to removable media. This used send/recv which is a clean way of managing such things. There has been some talk recently about the future of that feature, see the zfs-auto-snapshot forum to catch up on the conversation. NB. one reason send/recv in ZFS works like a well-designed split mirror using some other RAID software is because the same method is used to send incremental snapshots and resilver mirrors. > The mirror works fine, and resilvers properly and selectively when I > use "zpool offline" and "zpool online" on the zvol submirror. Not really. If you want to split mirrors for "backup" purposes, then you need "zpool split" which recently integrated into b131. It takes care of the dangling participles. -- richard > I don't want to have the usb disk attached all the time, nor even to > run with the mirror always active (usb is - just - slower than the > internal ssd). I'd like to be able to move this external disk between > hosts, and potentially repeat the rpool mirror for each, having them > resilver whenever the disk is attached. > > However, with the rpool mirror in place, I can't find a way to "zpool > export black". It complains that the poool is busy, because of the > zvol in use. This happens regardless of whether I have set the zvol > submirror offline. I expected that, with the subdevice in the offline > state, the zvol would be closed. > > Any suggestions? Is this worth filing as a bug (is the device really > offline)? Would it work differently if I used a file on the external > pool, instead of a zvol? (I haven't tried that yet, but don't really > expect a difference unless umount -f can help). > > -- > Dan. > _______________________________________________ > 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
