Date: Fri, 06 Jan 2012 16:56:46 -0500 From: Boris Kochergin <spawk@acm.poly.edu> To: Martin Birgmeier <Martin.Birgmeier@aon.at> Cc: freebsd-fs@freebsd.org Subject: Re: Upgrade to 9.0: How to convert zpool from adX to adaX? Message-ID: <4F076E1E.4040908@acm.poly.edu> In-Reply-To: <4F058075.1020108@aon.at> References: <4F04749E.9020301@aon.at> <20120104172351.GA42855@icarus.home.lan> <4F05586B.9060109@aon.at> <4F056EEB.3050902@gmail.com> <4F058075.1020108@aon.at>
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On 01/05/12 05:50, Martin Birgmeier wrote: > On 01/05/12 10:35, Volodymyr Kostyrko wrote: >> 05.01.2012 09:59, Martin Birgmeier wrote: >>> In 9.0, if I keep kern.cam.ada.legacy_aliases=1, there will be two >>> paths >>> to each device, one through adX, the other through adaX. Which one will >>> zfs use, and show with 'zpool status'? >> >> You are partially incorrect here: >> [torn] ~> ls -la /dev | grep ad >> lrwxr-xr-x 1 root wheel 4 5 jan 08:22 ad6@ -> ada0 >> lrwxr-xr-x 1 root wheel 5 5 jan 08:22 ad6a@ -> ada0a >> lrwxr-xr-x 1 root wheel 5 5 jan 08:22 ad6b@ -> ada0b >> lrwxr-xr-x 1 root wheel 5 5 jan 08:22 ad6d@ -> ada0d >> lrwxr-xr-x 1 root wheel 5 5 jan 08:22 ad6e@ -> ada0e >> lrwxr-xr-x 1 root wheel 5 5 jan 08:22 ad6f@ -> ada0f >> lrwxr-xr-x 1 root wheel 13 5 jan 08:22 ad6f.journal@ -> >> ada0f.journal >> crw-r----- 1 root operator 0, 64 5 jan 08:22 ada0 >> crw-r----- 1 root operator 0, 66 5 jan 08:23 ada0a >> crw-r----- 1 root operator 0, 68 5 jan 08:22 ada0b >> crw-r----- 1 root operator 0, 70 5 jan 08:23 ada0d >> crw-r----- 1 root operator 0, 72 5 jan 08:23 ada0e >> crw-r----- 1 root operator 0, 74 5 jan 08:22 ada0f >> crw-r----- 1 root operator 0, 79 5 jan 08:23 ada0f.journal >> >>> Also, I understand that I will have to wire down the various ATA >>> CAMs to >>> obtain the old numbering. How can I do this? Again, which path would >>> zfs >>> use if I did not wire down the ATA CAMs? Will I have half of my devices >>> go through adX and the other through adaX, or will zfs even believe >>> that >>> it has a multipath connectivity to each device? >> >> Not at all, ad6 would be a symlink to correct ada device, I haven't >> yet changed the fstab on this machine and it reads: >> >> # Device Mountpoint FStype Options Dump >> Pass# >> /dev/ad6b none swap sw >> 0 0 >> /dev/ad6a / ufs rw >> 1 1 >> /dev/ad6e /tmp ufs rw >> 2 2 >> /dev/ad6f.journal /usr ufs rw,async >> 2 2 >> /dev/ad6d /var ufs rw >> 2 2 >> /dev/cd0 /cdrom cd9660 ro,noauto >> 0 0 >> > Sigh... I get only half the answers, and these are not so helpful either. > > First of all, I *am* correct in saying that there are two paths to the > same device, because the purpose of a (sym-)link precisely is to have > an alternate path to the same object in the filesystem. So if someone > tells me that zfs somehow (how?) excludes devices reached through > symlinks, *that* would be an information I would find useful. > > Second, the whole purpose of the kern.cam.ada.legacy_aliases is to > have backwards compatibility for fstab etc by installing symlinks in > /dev. I know this very well but want to prepare for the day when I > want to get rid of the necessity for this compatibility. > > Third, I have now asked twice how to wire the ATA CAM devices, without > anybody even referring to that question. Well, I guess I'll have to > find that out myself. > > I do appreciate all answers, even more so as I perfectly understand > they are *free* answers, and maybe the above is even helpful to > someone else (and does not confuse them instead), but I'd appreciate > it even more if they were real answers. > > Regards, > > Martin > > _______________________________________________ > freebsd-fs@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-fs > To unsubscribe, send any mail to "freebsd-fs-unsubscribe@freebsd.org" I've recently had to move a raidz2 pool from a /dev/ad* system to a /dev/ada* system. I, too, desired the disk numbers in the output of "zpool status" to stay the same. I'll assume that the problem is similar enough. First, I exported the pool on the /dev/ad* system with "zpool export". Then, I connected the disks, in random order, to the /dev/ada* system and ran "zpool import". "zpool import" does not consult the /boot/zfs/zpool.cache file, which is what has the preconceived notions of what pools contain what disks. The output of "zpool import" was my old pool, with all its disks, now in /dev/ada* form, albeit in random order. I then swapped disks between controllers until I got the order desired, and imported the pool. -Boris
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