Thanks Keith, Chris and all, I’ve created a new ashift=12 zpool and am transferring the data across. All seems to be going well.
Thanks for the clarification. Cheers, Matt. On 17 Mar 2014, at 2:22 am, Keith Wesolowski <[email protected]> wrote: > On Sun, Mar 16, 2014 at 08:51:46PM +1000, Matt Connolly wrote: > >> I’m not trying to change the ashift of a pool, I’m trying to override the >> physical block size of a new 4k-sector sized device so I can attach it to an >> existing ashift=9 zpool. >> >> Perhaps I’m doing it backwards trying to add a 4k sector drive to a 512b >> sector pool, and the override only works the other way? > > Is this a 4k disk, or a 512e disk? It is possible to send 512-byte > commands to a 512e disk; it is not possible to send them to a 4k disk. > So convincing sd that a 4k disk has 512-byte sectors is not likely to > lead to any good outcome. That's why you'll note the following code at > sd.c:4227: > > if (strcasecmp(name, "physical-block-size") == 0) { > if (ddi_strtol(value, &endptr, 0, &val) == 0 && > ISP2(val) && val >= un->un_tgt_blocksize && > val >= un->un_sys_blocksize) { > un->un_phy_blocksize = val; > } else { > goto value_invalid; > } > ... > > So yes, this can be used only to increase the blocksize, not to decrease > it, for the reason described above. > >> If that’s the case, I’m happy to zfs send to a new ashift=12 pool. > > Recommended. > > > ------------------------------------------- > smartos-discuss > Archives: https://www.listbox.com/member/archive/184463/=now > RSS Feed: https://www.listbox.com/member/archive/rss/184463/25829874-a4d57667 > Modify Your Subscription: https://www.listbox.com/member/?&; > Powered by Listbox: http://www.listbox.com ------------------------------------------- smartos-discuss Archives: https://www.listbox.com/member/archive/184463/=now RSS Feed: https://www.listbox.com/member/archive/rss/184463/25769125-55cfbc00 Modify Your Subscription: https://www.listbox.com/member/?member_id=25769125&id_secret=25769125-7688e9fb Powered by Listbox: http://www.listbox.com
