Date: Thu, 21 May 2015 08:19:37 -0400 (EDT) From: Rick Macklem <rmacklem@uoguelph.ca> To: Mahmoud Al-Qudsi <mqudsi@neosmart.net> Cc: freebsd-stable@freebsd.org Subject: Re: Status of NFS4.1 FS_RECLAIM in FreeBSD 10.1? Message-ID: <1950364073.41930419.1432210777686.JavaMail.root@uoguelph.ca> In-Reply-To: <C6B65105-0DA8-488A-B099-A8DEC404AA22@neosmart.net>
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Mahmoud Al-Qudsi wrote: > On May 20, 2015, at 8:57 PM, Rick Macklem <rmacklem@uoguelph.ca> > wrote: > > Only the global RECLAIM_COMPLETE is implemented. I'll be honest > > that > > I don't even really understand what the "single fs > > reclaim_complete" > > semantics are and, as such, it isn't implemented. >=20 > Thanks for verifying that. >=20 > > I think it is meant to be used when a file system is migrated from > > one server to another (transferring the locks to the new server) or > > something like that. > > Migration/replication isn't supported. Maybe someday if I figure > > out > > what the RFC expects the server to do for this case. >=20 > I wasn=E2=80=99t clear on if this was lock reclaiming or block reclaiming= . > Thanks. >=20 > >> I can mount and use NFSv3 shares just fine with ESXi from this > >> same > >> server, and > >> can mount the same shares as NFSv4 from other clients (e.g. OS X) > >> as > >> well. > >>=20 > > This is NFSv4.1 specific, so NFSv4.0 should work, I think. Or just > > use NFSv3. > >=20 > > rick >=20 > For some reason, ESXi doesn=E2=80=99t do ESXi 4.0, only v3 or v4.1. >=20 > I am using NFS v3 for now, but unless I=E2=80=99m mistaken, since FreeBSD > supports > neither =E2=80=9Cnohide=E2=80=9D nor =E2=80=9Ccrossmnt=E2=80=9D there is = no way for a single > export(/import) > to cross ZFS filesystem boundaries. >=20 > I am using ZFS snapshots to manage virtual machine images, each > machine > has its own ZFS filesystem so I can snapshot and rollback > individually. But > this means that under NFSv3 (so far as I can tell), each =E2=80=9Cfolder= =E2=80=9D > (ZFS fs) > must be mounted separately on the ESXi host. I can get around > exporting > them each individually with the -alldirs parameter, but client-side, > there does > not seem to be a way of traversing ZFS filesystem mounts without > explicitly > mounting each and every one - a maintenance nightmare if there ever > was one. >=20 > The only thing I can think of would be unions for the top-level > directory, but I=E2=80=99m > very, very leery of the the nullfs/unionfs modules as they=E2=80=99ve bee= n a > source of > system instability for us in the past (deadlocks, undetected lock > inversions, etc). > That and I really rather a maintenance nightmare than a hack. >=20 > Would you have any other suggestions? >=20 Well, if you are just doing an NFSv4.1 mount, you could capture packets during the failed mount attaempt with tcpdump and then email me the raw packet capture, I can take a look at it. (tcpdump doesn't handle nfs packets well, but wireshark will accept a raw packet capture) Something like: # tcpdump -s 0 -w <file>.pcap host <nfs-client> should work. When I read RFC-5661 around page #567, it seems clear that the client should use RECLAIM_COMPLETE with the fs arg false after acquiring a noew clientid, which is what a fresh mount would normally be. (If the packet capture shows an EXCHANGEID followed by a RECLAIM_COMPLETE with the fs arg true, I think ESXi is broken, but I can send you a patch that will just ignore the "true", so it works.) I think the "true" case is only used when a file system has been "moved" by a server cluster, indicated to the client via a NFS4ERR_MOVED error when it is accessed at the old server, but the working in RFC-5661 isn't very clear. rick > Thanks, >=20 > Mahmoud >=20 > _______________________________________________ > freebsd-stable@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-stable > To unsubscribe, send any mail to > "freebsd-stable-unsubscribe@freebsd.org"
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