4.1 no-pnfs mount option?
Subsystems (2)
Is there some way (mount option?) I can ask the client to attempt a 4.1 (sessions) mount but do not use pnfs?
No mount option - just configure your machine to not load any pnfs layoutdriver modules.
-->Andy
Quoted 7 lines · Jim Rees
Is there some way (mount option?) I can ask the client to attempt a 4.1 (sessions) mount but do not use pnfs?
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William A. (Andy) Adamson wrote:
No mount option - just configure your machine to not load any pnfs layoutdriver modules.
That works, thanks, but I was hoping for a way to have layout and non-layout mounts going on at the same time.
Quoted 7 lines · Jim Rees
William A. (Andy) Adamson wrote:
No mount option - just configure your machine to not load any pnfs layoutdriver modules.
That works, thanks, but I was hoping for a way to have layout and non-layout mounts going on at the same time.
I guess that means two clients.
-->Andy
Quoted 4 lines
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Quoted 7 lines · Jim Rees
William A. (Andy) Adamson wrote:
No mount option - just configure your machine to not load any pnfs layoutdriver modules.
That works, thanks, but I was hoping for a way to have layout and non-layout mounts going on at the same time.
Different VMs?
Trond
Quoted 16 lines
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Trond Myklebust
Sent: Friday, January 14, 2011 7:42 AM
To: Jim Rees
Cc: William A. (Andy) Adamson; [email protected]
Subject: Re: 4.1 no-pnfs mount option?Quoted 5 lines · Jim Rees
William A. (Andy) Adamson wrote:
No mount option - just configure your machine to not load any pnfs layoutdriver modules.
Quoted 7 lines
Quoted 1 line
That works, thanks, but I was hoping for a way to have
layout and non-layout
Quoted 1 line
mounts going on at the same time.
Different VMs?
Trond
Would there be any objections to adding a "nopnfs" mount option to force this behavior? It could be useful at least for testing, possibly for working around server problems, or if an admin knows that certain clients' usage patterns would be better served by disabling pnfs.
-Dan
Quoted 8 lines
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Quoted 16 lines · On Tue, 2011-01-18 at 12:44 -0500, [email protected] wrote:
Quoted 16 lines
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Trond Myklebust
Sent: Friday, January 14, 2011 7:42 AM
To: Jim Rees
Cc: William A. (Andy) Adamson; [email protected]
Subject: Re: 4.1 no-pnfs mount option?Quoted 6 lines · Jim Rees
William A. (Andy) Adamson wrote:
No mount option - just configure your machine to not load any pnfs layoutdriver modules.
That works, thanks, but I was hoping for a way to have
Quoted 8 lines
Quoted 6 lines
layout and non-layout
Quoted 1 line
mounts going on at the same time.
Different VMs?
Trond
Would there be any objections to adding a "nopnfs" mount option to force this behavior? It could be useful at least for testing, possibly for working around server problems, or if an admin knows that certain clients' usage patterns would be better served by disabling pnfs.
Yes. Why should we be adding debugging mount options to the upstream code? Just test the damned pnfs code properly before it goes upstream...
Trond
Signature · 6 lines
Trond Myklebust Linux NFS client maintainer NetApp [email protected] www.netapp.com
Quoted 22 lines · Trond Myklebust
Quoted 21 lines · On Tue, 2011-01-18 at 12:44 -0500, [email protected] wrote:
Quoted 21 lines
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Trond Myklebust
Sent: Friday, January 14, 2011 7:42 AM
To: Jim Rees
Cc: William A. (Andy) Adamson; [email protected]
Subject: Re: 4.1 no-pnfs mount option?Quoted 6 lines · Jim Rees
William A. (Andy) Adamson wrote:
No mount option - just configure your machine to not load any pnfs layoutdriver modules.
That works, thanks, but I was hoping for a way to have
layout and non-layout
Quoted 1 line
mounts going on at the same time.
Different VMs?
Quoted 8 lines
Quoted 3 lines
Quoted 1 line
Trond
Would there be any objections to adding a "nopnfs" mount option to force this behavior? It could be useful at least for testing, possibly for working around server problems, or if an admin knows that certain clients' usage patterns would be better served by disabling pnfs.
Yes. Why should we be adding debugging mount options to the upstream code? Just test the damned pnfs code properly before it goes upstream...
Trond
Such a mount option could be useful for dealing with buggy servers (pnfs-wise) so you could mount one server with pnfs and another without.
Benny
Quoted 27 lines · Benny Halevy
Quoted 26 lines · Trond Myklebust
Quoted 24 lines · On Tue, 2011-01-18 at 12:44 -0500, [email protected] wrote:
Quoted 15 lines
-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Trond Myklebust
Sent: Friday, January 14, 2011 7:42 AM
To: Jim Rees
Cc: William A. (Andy) Adamson; [email protected]
Subject: Re: 4.1 no-pnfs mount option?Quoted 5 lines · Jim Rees
William A. (Andy) Adamson wrote:
No mount option - just configure your machine to not load any pnfs layoutdriver modules.
Quoted 7 lines
Quoted 1 line
That works, thanks, but I was hoping for a way to have
layout and non-layout
Quoted 1 line
mounts going on at the same time.
Different VMs?
Trond
Would there be any objections to adding a "nopnfs" mount option to force this behavior? It could be useful at least for testing, possibly for working around server problems, or if an admin knows that certain clients' usage patterns would be better served by disabling pnfs.
Quoted 7 lines
Quoted 4 lines
Yes. Why should we be adding debugging mount options to the upstream code? Just test the damned pnfs code properly before it goes upstream...
Trond
Such a mount option could be useful for dealing with buggy servers (pnfs-wise) so you could mount one server with pnfs and another without.
You can find ways around that. Just use 2 clients: one with pnfs switched on, and one with it off.
I really don't want to introduce mount options upstream unless they are useful in the long term. One off usefulness does not pass that test.
Signature · 6 lines
Trond Myklebust Linux NFS client maintainer NetApp [email protected] www.netapp.com
Hi,
Isn't by mount a plausible way to select for pnfs independent of debugging? Is it assured that a client administrator would never reasonably wish to do this?
Matt
Quoted 25 lines · ----- "Trond Myklebust
Quoted 2 lines
Such a mount option could be useful for dealing with buggy servers
(pnfs-wise) so you
Quoted 1 line
could mount one server with pnfs and another without.
You can find ways around that. Just use 2 clients: one with pnfs switched on, and one with it off.
I really don't want to introduce mount options upstream unless they are
useful in the long term. One off usefulness does not pass that test.Signature · 12 lines
Trond Myklebust Linux NFS client maintainer NetApp [email protected] www.netapp.com -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
Signature · 11 lines
Matt Benjamin The Linux Box 206 South Fifth Ave. Suite 150 Ann Arbor, MI 48104 http://linuxbox.com tel. 734-761-4689 fax. 734-769-8938 cel. 734-216-5309
Quoted 3 lines · Matt W. Benjamin
Hi,
Isn't by mount a plausible way to select for pnfs independent of debugging? Is it assured that a client administrator would never reasonably wish to do this?
"Why would an administrator never want to do this?" is not a helpful question.
A more useful question is "what reason would you possibly have for overriding the server's request that you do pNFS when your client has pNFS support?" What makes pNFS so special that we must allow administrators to do this on a per-mount basis?
Throwing more and more knobs into the kernel is easy. The difficult bit is to figure out which are useful knobs, and that is why I want real use cases...
Trond
Quoted 28 lines
Quoted 25 lines · ----- "Trond Myklebust
Quoted 2 lines
Such a mount option could be useful for dealing with buggy servers
(pnfs-wise) so you
Quoted 1 line
could mount one server with pnfs and another without.
You can find ways around that. Just use 2 clients: one with pnfs switched on, and one with it off.
I really don't want to introduce mount options upstream unless they are
useful in the long term. One off usefulness does not pass that test.Signature · 12 lines
Trond Myklebust Linux NFS client maintainer NetApp [email protected] www.netapp.com -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
Signature · 6 lines
Trond Myklebust Linux NFS client maintainer NetApp [email protected] www.netapp.com
Quoted 17 lines
-----Original Message-----
From: Trond Myklebust [mailto:[email protected]]
Sent: Tuesday, January 18, 2011 11:15 AM
To: Matt W. Benjamin
Cc: Muntz, Daniel; [email protected]; [email protected]; [email protected]; Benny Halevy
Subject: Re: 4.1 no-pnfs mount option?Quoted 3 lines · Matt W. Benjamin
Hi,
Isn't by mount a plausible way to select for pnfs
independent of debugging? Is it assured that a client administrator would never reasonably wish to do this?
Quoted 7 lines
"Why would an administrator never want to do this?" is not a helpful question.
A more useful question is "what reason would you possibly have for overriding the server's request that you do pNFS when your client has pNFS support?" What makes pNFS so special that we must allow administrators to do this on a per-mount basis?
By the same logic, why should a user be allowed to select which version of NFS they use for mounting when the server has a perfectly reasonable way of negotiating it? Getting to choose v2 vs. v3 vs. v4 seems like much less of a distinction than choosing between pNFS and no pNFS. Frankly, it never even occurred to me that there wouldn't be a mount option to make this choice. Enabling/disabling the layout driver doesn't fit the existing model of choosing mount behavior, and is a big hammer--it's all or nothing.
Anyway, here's a use case: I'm working at an HPC/gas+oil/satellite data site. We have an awesome pNFS server for our big data and I want to access my big data with pNFS. We have another server for homedirs, some big data, and other stuff. Some mounts are fine with pNFS, others are abysmal. So, I want to mount some directories with pNFS, and some without pNFS, on the same client, independent of the server configuration.
Quoted 53 lines
Throwing more and more knobs into the kernel is easy. The difficult bit
is to figure out which are useful knobs, and that is why I want real use
cases...Trond
Quoted 4 lines
Quoted 2 lines · ----- "Trond Myklebust
Quoted 2 lines
Such a mount option could be useful for dealing with
buggy servers
Quoted 7 lines
Quoted 7 lines
(pnfs-wise) so you
Quoted 1 line
could mount one server with pnfs and another without.
You can find ways around that. Just use 2 clients: one with pnfs switched on, and one with it off.
I really don't want to introduce mount options upstream
unless they
Quoted 2 lines
Quoted 2 lines
are
useful in the long term. One off usefulness does not passthat test.
Quoted 11 lines
Quoted 11 lines
Signature · 10 lines
-- Trond Myklebust Linux NFS client maintainer NetApp [email protected] www.netapp.com -- To unsubscribe from this list: send the line "unsubscribelinux-nfs"
Quoted 4 lines
Quoted 3 lines
in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.htmlSignature · 6 lines
Trond Myklebust Linux NFS client maintainer NetApp [email protected] www.netapp.com
Quoted 19 lines · On Tue, 2011-01-18 at 19:53 -0500, [email protected] wrote:
Quoted 19 lines
-----Original Message-----
From: Trond Myklebust [mailto:[email protected]]
Sent: Tuesday, January 18, 2011 11:15 AM
To: Matt W. Benjamin
Cc: Muntz, Daniel; [email protected]; [email protected]; [email protected]; Benny Halevy
Subject: Re: 4.1 no-pnfs mount option?Quoted 3 lines · Matt W. Benjamin
Hi,
Isn't by mount a plausible way to select for pnfs
independent of debugging? Is it assured that a client administrator would never reasonably wish to do this?
"Why would an administrator never want to do this?" is not a helpful question.
Quoted 8 lines
Quoted 4 lines
A more useful question is "what reason would you possibly have for overriding the server's request that you do pNFS when your client has pNFS support?" What makes pNFS so special that we must allow administrators to do this on a per-mount basis?
By the same logic, why should a user be allowed to select which version of NFS they use for mounting when the server has a perfectly reasonable way of negotiating it? Getting to choose v2 vs. v3 vs. v4 seems like much less of a distinction than choosing between pNFS and no pNFS. Frankly, it never even occurred to me that there wouldn't be a mount option to make this choice. Enabling/disabling the layout driver doesn't fit the existing model of choosing mount behavior, and is a big hammer--it's all or nothing.
Anyway, here's a use case: I'm working at an HPC/gas+oil/satellite data site. We have an awesome pNFS server for our big data and I want to access my big data with pNFS. We have another server for homedirs, some big data, and other stuff. Some mounts are fine with pNFS, others are abysmal. So, I want to mount some directories with pNFS, and some without pNFS, on the same client, independent of the server configuration.
mount -t nfs -overs=4,minorversion=0 foo:/ /bar
Done... Any more questions?
Signature · 6 lines
Trond Myklebust Linux NFS client maintainer NetApp [email protected] www.netapp.com
Quoted 57 lines
-----Original Message-----
From: Trond Myklebust [mailto:[email protected]]
Sent: Tuesday, January 18, 2011 5:45 PM
To: Muntz, Daniel
Cc: [email protected]; [email protected]; [email protected]; [email protected]; [email protected]
Subject: RE: 4.1 no-pnfs mount option?Quoted 9 lines · On Tue, 2011-01-18 at 19:53 -0500, [email protected] wrote:
Quoted 9 lines
-----Original Message-----
From: Trond Myklebust [mailto:[email protected]]
Sent: Tuesday, January 18, 2011 11:15 AM
To: Matt W. Benjamin
Cc: Muntz, Daniel; [email protected]; [email protected]; [email protected]; Benny Halevy
Subject: Re: 4.1 no-pnfs mount option?Quoted 8 lines
Quoted 8 lines · Matt W. Benjamin
Quoted 3 lines
Hi,
Isn't by mount a plausible way to select for pnfs
independent of debugging? Is it assured that a client administrator would never reasonably wish to do this?
"Why would an administrator never want to do this?" is
not a helpful
Quoted 4 lines
Quoted 4 lines
question.
A more useful question is "what reason would you possibly have for overriding the server's request that you do pNFS when
your client has
Quoted 4 lines
Quoted 2 lines
pNFS support?" What makes pNFS so special that we must allow administrators to do this on a per-mount basis?
By the same logic, why should a user be allowed to select
which version of NFS they use for mounting when the server has a perfectly reasonable way of negotiating it? Getting to choose v2 vs. v3 vs. v4 seems like much less of a distinction than choosing between pNFS and no pNFS. Frankly, it never even occurred to me that there wouldn't be a mount option to make this choice. Enabling/disabling the layout driver doesn't fit the existing model of choosing mount behavior, and is a big hammer--it's all or nothing.
Quoted 2 lines
Anyway, here's a use case: I'm working at an
HPC/gas+oil/satellite data site. We have an awesome pNFS server for our big data and I want to access my big data with pNFS. We have another server for homedirs, some big data, and other stuff. Some mounts are fine with pNFS, others are abysmal. So, I want to mount some directories with pNFS, and some without pNFS, on the same client, independent of the server configuration.
Quoted 3 lines
mount -t nfs -overs=4,minorversion=0 foo:/ /bar
Done... Any more questions?
Several, but I'll stick to one rhetorical. Does NFSv4.1 have any features, other than pNFS, that are not in 4.0?
Quoted 11 lines
Signature · 7 lines
-- Trond Myklebust Linux NFS client maintainer NetApp [email protected] www.netapp.com
Quoted 56 lines · On Tue, 2011-01-18 at 21:29 -0500, [email protected] wrote:
Quoted 56 lines
-----Original Message-----
From: Trond Myklebust [mailto:[email protected]]
Sent: Tuesday, January 18, 2011 5:45 PM
To: Muntz, Daniel
Cc: [email protected]; [email protected]; [email protected]; [email protected]; [email protected]
Subject: RE: 4.1 no-pnfs mount option?Quoted 9 lines · On Tue, 2011-01-18 at 19:53 -0500, [email protected] wrote:
Quoted 9 lines
-----Original Message-----
From: Trond Myklebust [mailto:[email protected]]
Sent: Tuesday, January 18, 2011 11:15 AM
To: Matt W. Benjamin
Cc: Muntz, Daniel; [email protected]; [email protected]; [email protected]; Benny Halevy
Subject: Re: 4.1 no-pnfs mount option?Quoted 8 lines
Quoted 8 lines · Matt W. Benjamin
Quoted 3 lines
Hi,
Isn't by mount a plausible way to select for pnfs
independent of debugging? Is it assured that a client administrator would never reasonably wish to do this?
"Why would an administrator never want to do this?" is
not a helpful
Quoted 4 lines
Quoted 4 lines
question.
A more useful question is "what reason would you possibly have for overriding the server's request that you do pNFS when
your client has
Quoted 4 lines
Quoted 2 lines
pNFS support?" What makes pNFS so special that we must allow administrators to do this on a per-mount basis?
By the same logic, why should a user be allowed to select
which version of NFS they use for mounting when the server has a perfectly reasonable way of negotiating it? Getting to choose v2 vs. v3 vs. v4 seems like much less of a distinction than choosing between pNFS and no pNFS. Frankly, it never even occurred to me that there wouldn't be a mount option to make this choice. Enabling/disabling the layout driver doesn't fit the existing model of choosing mount behavior, and is a big hammer--it's all or nothing.
Quoted 2 lines
Anyway, here's a use case: I'm working at an
HPC/gas+oil/satellite data site. We have an awesome pNFS server for our big data and I want to access my big data with pNFS. We have another server for homedirs, some big data, and other stuff. Some mounts are fine with pNFS, others are abysmal. So, I want to mount some directories with pNFS, and some without pNFS, on the same client, independent of the server configuration.
Quoted 5 lines
Quoted 3 lines
mount -t nfs -overs=4,minorversion=0 foo:/ /bar
Done... Any more questions?
Several, but I'll stick to one rhetorical. Does NFSv4.1 have any features, other than pNFS, that are not in 4.0?
Why stop now, when you were batting 100? I told you what the criteria were for adding more mount options, and you start whining about not being able to conceive of a world without mount options.
The point is that NFSv4.1 was supposed to let the _server_ tell the client when to use pNFS. The reason why you let the _server_ do this, is because pNFS is about enabling _server_ scalability. It is not about faster clients...
If you don't want the client to use pNFS, then fix the _server_ settings...
Signature · 6 lines
Trond Myklebust Linux NFS client maintainer NetApp [email protected] www.netapp.com
The server has indicated that it supports pnfs. Why is the client obligated to request it?
Matt
Quoted 84 lines · ----- "Trond Myklebust
Quoted 24 lines · On Tue, 2011-01-18 at 21:29 -0500, [email protected] wrote:
Quoted 24 lines
-----Original Message-----
From: Trond Myklebust [mailto:[email protected]]
Sent: Tuesday, January 18, 2011 5:45 PM
To: Muntz, Daniel
Cc: [email protected]; [email protected]; [email protected]; [email protected]; [email protected]
Subject: RE: 4.1 no-pnfs mount option?Quoted 13 lines · On Tue, 2011-01-18 at 19:53 -0500, [email protected] wrote:
Quoted 13 lines
-----Original Message-----
From: Trond Myklebust [mailto:[email protected]]
Sent: Tuesday, January 18, 2011 11:15 AM
To: Matt W. Benjamin
Cc: Muntz, Daniel; [email protected]; [email protected]; [email protected]; Benny Halevy
Subject: Re: 4.1 no-pnfs mount option?Quoted 3 lines · Matt W. Benjamin
Hi,
Isn't by mount a plausible way to select for pnfs
Quoted 8 lines
Quoted 8 lines
Quoted 4 lines
Quoted 4 lines
independent of debugging? Is it assured that a client administrator would never reasonably wish to do this?
"Why would an administrator never want to do this?" is
not a helpful
Quoted 3 lines
Quoted 3 lines
question.
A more useful question is "what reason would you possibly have
for
Quoted 24 lines
Quoted 24 lines
Quoted 1 line
Quoted 1 line
overriding the server's request that you do pNFS when
your client has
Quoted 4 lines
Quoted 2 lines
pNFS support?" What makes pNFS so special that we must allow administrators to do this on a per-mount basis?
By the same logic, why should a user be allowed to select
which version of NFS they use for mounting when the server has a perfectly reasonable way of negotiating it? Getting to choose v2 vs. v3 vs. v4 seems like much less of a distinction than choosing between pNFS and no pNFS. Frankly, it never even occurred to me that there wouldn't be a mount option to make this choice. Enabling/disabling the layout driver doesn't fit the existing model of choosing mount behavior, and is a big hammer--it's all or nothing.
Quoted 2 lines
Anyway, here's a use case: I'm working at an
HPC/gas+oil/satellite data site. We have an awesome pNFS server for our big data and I want to access my big data with pNFS. We have another server for homedirs, some big data, and other stuff. Some mounts are fine with pNFS, others are abysmal. So, I want to mount some directories with pNFS, and some without pNFS, on the same client, independent of the server configuration.
Quoted 5 lines
Quoted 3 lines
mount -t nfs -overs=4,minorversion=0 foo:/ /bar
Done... Any more questions?
Several, but I'll stick to one rhetorical. Does NFSv4.1 have any
features, other than pNFS, that are not in 4.0?
Why stop now, when you were batting 100? I told you what the criteria were for adding more mount options, and you start whining about not being able to conceive of a world without mount options.
The point is that NFSv4.1 was supposed to let the _server_ tell the client when to use pNFS. The reason why you let the _server_ do this, is
because pNFS is about enabling _server_ scalability. It is not about faster clients...
If you don't want the client to use pNFS, then fix the _server_ settings...Signature · 6 lines
Trond Myklebust Linux NFS client maintainer NetApp [email protected] www.netapp.com
Signature · 11 lines
Matt Benjamin The Linux Box 206 South Fifth Ave. Suite 150 Ann Arbor, MI 48104 http://linuxbox.com tel. 734-761-4689 fax. 734-769-8938 cel. 734-216-5309
Quoted 1 line · Matt W. Benjamin
The server has indicated that it supports pnfs. Why is the client obligated to request it?
It is not required by the protocol, but the client had better have a damned good reason for not doing so. As stated several times previously, pNFS is all about increasing _server_ scalability. If the server doesn't need to scale out, why would it tell us to use pNFS for those files in the first place?
Trond
Quoted 87 lines
Quoted 84 lines · ----- "Trond Myklebust
Quoted 24 lines · On Tue, 2011-01-18 at 21:29 -0500, [email protected] wrote:
Quoted 24 lines
-----Original Message-----
From: Trond Myklebust [mailto:[email protected]]
Sent: Tuesday, January 18, 2011 5:45 PM
To: Muntz, Daniel
Cc: [email protected]; [email protected]; [email protected]; [email protected]; [email protected]
Subject: RE: 4.1 no-pnfs mount option?Quoted 13 lines · On Tue, 2011-01-18 at 19:53 -0500, [email protected] wrote:
Quoted 13 lines
-----Original Message-----
From: Trond Myklebust [mailto:[email protected]]
Sent: Tuesday, January 18, 2011 11:15 AM
To: Matt W. Benjamin
Cc: Muntz, Daniel; [email protected]; [email protected]; [email protected]; Benny Halevy
Subject: Re: 4.1 no-pnfs mount option?Quoted 3 lines · Matt W. Benjamin
Hi,
Isn't by mount a plausible way to select for pnfs
Quoted 8 lines
Quoted 8 lines
Quoted 4 lines
Quoted 4 lines
independent of debugging? Is it assured that a client administrator would never reasonably wish to do this?
"Why would an administrator never want to do this?" is
not a helpful
Quoted 3 lines
Quoted 3 lines
question.
A more useful question is "what reason would you possibly have
for
Quoted 24 lines
Quoted 24 lines
Quoted 1 line
Quoted 1 line
overriding the server's request that you do pNFS when
your client has
Quoted 4 lines
Quoted 2 lines
pNFS support?" What makes pNFS so special that we must allow administrators to do this on a per-mount basis?
By the same logic, why should a user be allowed to select
which version of NFS they use for mounting when the server has a perfectly reasonable way of negotiating it? Getting to choose v2 vs. v3 vs. v4 seems like much less of a distinction than choosing between pNFS and no pNFS. Frankly, it never even occurred to me that there wouldn't be a mount option to make this choice. Enabling/disabling the layout driver doesn't fit the existing model of choosing mount behavior, and is a big hammer--it's all or nothing.
Quoted 2 lines
Anyway, here's a use case: I'm working at an
HPC/gas+oil/satellite data site. We have an awesome pNFS server for our big data and I want to access my big data with pNFS. We have another server for homedirs, some big data, and other stuff. Some mounts are fine with pNFS, others are abysmal. So, I want to mount some directories with pNFS, and some without pNFS, on the same client, independent of the server configuration.
Quoted 5 lines
Quoted 3 lines
mount -t nfs -overs=4,minorversion=0 foo:/ /bar
Done... Any more questions?
Several, but I'll stick to one rhetorical. Does NFSv4.1 have any
features, other than pNFS, that are not in 4.0?
Why stop now, when you were batting 100? I told you what the criteria were for adding more mount options, and you start whining about not being able to conceive of a world without mount options.
The point is that NFSv4.1 was supposed to let the _server_ tell the client when to use pNFS. The reason why you let the _server_ do this, is
because pNFS is about enabling _server_ scalability. It is not about faster clients...
If you don't want the client to use pNFS, then fix the _server_ settings...Signature · 6 lines
Trond Myklebust Linux NFS client maintainer NetApp [email protected] www.netapp.com
Signature · 6 lines
Trond Myklebust Linux NFS client maintainer NetApp [email protected] www.netapp.com
Quoted 80 lines
-----Original Message-----
From: Trond Myklebust [mailto:[email protected]]
Sent: Tuesday, January 18, 2011 6:57 PM
To: Muntz, Daniel
Cc: [email protected]; [email protected]; [email protected]; [email protected]; [email protected]
Subject: RE: 4.1 no-pnfs mount option?Quoted 24 lines · On Tue, 2011-01-18 at 21:29 -0500, [email protected] wrote:
Quoted 24 lines
-----Original Message-----
From: Trond Myklebust [mailto:[email protected]]
Sent: Tuesday, January 18, 2011 5:45 PM
To: Muntz, Daniel
Cc: [email protected]; [email protected]; [email protected]; [email protected]; [email protected]
Subject: RE: 4.1 no-pnfs mount option?Quoted 13 lines · On Tue, 2011-01-18 at 19:53 -0500, [email protected] wrote:
Quoted 13 lines
-----Original Message-----
From: Trond Myklebust [mailto:[email protected]]
Sent: Tuesday, January 18, 2011 11:15 AM
To: Matt W. Benjamin
Cc: Muntz, Daniel; [email protected]; [email protected]; [email protected]; Benny Halevy
Subject: Re: 4.1 no-pnfs mount option?Quoted 3 lines · Matt W. Benjamin
Hi,
Isn't by mount a plausible way to select for pnfs
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independent of debugging? Is it assured that a client administrator would never reasonably wish to do this?
"Why would an administrator never want to do this?" is
not a helpful
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question.
A more useful question is "what reason would you
possibly have for
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overriding the server's request that you do pNFS when
your client has
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pNFS support?" What makes pNFS so special that we must allow administrators to do this on a per-mount basis?
By the same logic, why should a user be allowed to select
which version of NFS they use for mounting when the server has a perfectly reasonable way of negotiating it? Getting to choose v2 vs. v3 vs. v4 seems like much less of a distinction than choosing between pNFS and no pNFS. Frankly, it never even occurred to me that there wouldn't be a mount option to make this choice. Enabling/disabling the layout driver doesn't fit the existing model of choosing mount behavior, and is a big hammer--it's all or nothing.
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Anyway, here's a use case: I'm working at an
HPC/gas+oil/satellite data site. We have an awesome pNFS server for our big data and I want to access my big data with pNFS. We have another server for homedirs, some big data, and other stuff. Some mounts are fine with pNFS, others are abysmal. So, I want to mount some directories with pNFS, and some without pNFS, on the same client, independent of the server configuration.
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mount -t nfs -overs=4,minorversion=0 foo:/ /bar
Done... Any more questions?
Several, but I'll stick to one rhetorical. Does NFSv4.1
have any features, other than pNFS, that are not in 4.0?
Why stop now, when you were batting 100? I told you what the criteria were for adding more mount options, and you start whining about not being able to conceive of a world without mount options.
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The point is that NFSv4.1 was supposed to let the _server_ tell the client when to use pNFS. The reason why you let the _server_ do this, is
because pNFS is about enabling _server_ scalability. It is not about faster clients...
If you don't want the client to use pNFS, then fix the _server_ settings...
I don't miss the kiss-up-kick-down model of software development...
The criteria was a use case, so I gave a use case. I wouldn't rule out the "testing use case" either, as a mount option makes it possible to test mixed pnfs/non-pnfs 4.1 traffic without multiple servers.
The point is that pNFS, like everything else, is about the users.
-Dan
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Signature · 7 lines
-- Trond Myklebust Linux NFS client maintainer NetApp [email protected] www.netapp.com
Quoted 87 lines · On Wed, 2011-01-19 at 00:54 -0500, [email protected] wrote:
Quoted 79 lines
-----Original Message-----
From: Trond Myklebust [mailto:[email protected]]
Sent: Tuesday, January 18, 2011 6:57 PM
To: Muntz, Daniel
Cc: [email protected]; [email protected]; [email protected]; [email protected]; [email protected]
Subject: RE: 4.1 no-pnfs mount option?Quoted 24 lines · On Tue, 2011-01-18 at 21:29 -0500, [email protected] wrote:
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-----Original Message-----
From: Trond Myklebust [mailto:[email protected]]
Sent: Tuesday, January 18, 2011 5:45 PM
To: Muntz, Daniel
Cc: [email protected]; [email protected]; [email protected]; [email protected]; [email protected]
Subject: RE: 4.1 no-pnfs mount option?Quoted 13 lines · On Tue, 2011-01-18 at 19:53 -0500, [email protected] wrote:
Quoted 13 lines
-----Original Message-----
From: Trond Myklebust [mailto:[email protected]]
Sent: Tuesday, January 18, 2011 11:15 AM
To: Matt W. Benjamin
Cc: Muntz, Daniel; [email protected]; [email protected]; [email protected]; Benny Halevy
Subject: Re: 4.1 no-pnfs mount option?Quoted 3 lines · Matt W. Benjamin
Hi,
Isn't by mount a plausible way to select for pnfs
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independent of debugging? Is it assured that a client administrator would never reasonably wish to do this?
"Why would an administrator never want to do this?" is
not a helpful
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question.
A more useful question is "what reason would you
possibly have for
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overriding the server's request that you do pNFS when
your client has
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pNFS support?" What makes pNFS so special that we must allow administrators to do this on a per-mount basis?
By the same logic, why should a user be allowed to select
which version of NFS they use for mounting when the server has a perfectly reasonable way of negotiating it? Getting to choose v2 vs. v3 vs. v4 seems like much less of a distinction than choosing between pNFS and no pNFS. Frankly, it never even occurred to me that there wouldn't be a mount option to make this choice. Enabling/disabling the layout driver doesn't fit the existing model of choosing mount behavior, and is a big hammer--it's all or nothing.
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Anyway, here's a use case: I'm working at an
HPC/gas+oil/satellite data site. We have an awesome pNFS server for our big data and I want to access my big data with pNFS. We have another server for homedirs, some big data, and other stuff. Some mounts are fine with pNFS, others are abysmal. So, I want to mount some directories with pNFS, and some without pNFS, on the same client, independent of the server configuration.
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mount -t nfs -overs=4,minorversion=0 foo:/ /bar
Done... Any more questions?
Several, but I'll stick to one rhetorical. Does NFSv4.1
have any features, other than pNFS, that are not in 4.0?
Why stop now, when you were batting 100? I told you what the criteria were for adding more mount options, and you start whining about not being able to conceive of a world without mount options.
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The point is that NFSv4.1 was supposed to let the _server_ tell the client when to use pNFS. The reason why you let the _server_ do this, is
because pNFS is about enabling _server_ scalability. It is not about faster clients...
If you don't want the client to use pNFS, then fix the _server_ settings...
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I don't miss the kiss-up-kick-down model of software development...
The criteria was a use case, so I gave a use case. I wouldn't rule out the "testing use case" either, as a mount option makes it possible to test mixed pnfs/non-pnfs 4.1 traffic without multiple servers.
The point is that pNFS, like everything else, is about the users.
The criteria was a use case that explains adequately why the client needs to be able to override the server settings, not just random 'I might want to do this' moments.
Rhetorical crap like 'it's about the users' isn't helping much either.
Signature · 6 lines
Trond Myklebust Linux NFS client maintainer NetApp [email protected] www.netapp.com
Have we beaten this dead horse to a pulp yet? I was just asking if there was such an option, not advocating for adding one. It would have been useful at the time for my own testing but I can see the argument against adding unwanted knobs.
The discussion has been useful in one way. I will now be spending some time making sure the block layout driver falls back gracefully to no-pnfs if, for example, an iscsi target can't be contacted.
Quoted 33 lines · Trond Myklebust
Quoted 32 lines · Benny Halevy
Quoted 30 lines · Trond Myklebust
Quoted 16 lines · On Tue, 2011-01-18 at 12:44 -0500, [email protected] wrote:
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-----Original Message-----
From: [email protected] [mailto:[email protected]] On Behalf Of Trond Myklebust
Sent: Friday, January 14, 2011 7:42 AM
To: Jim Rees
Cc: William A. (Andy) Adamson; [email protected]
Subject: Re: 4.1 no-pnfs mount option?Quoted 6 lines · Jim Rees
William A. (Andy) Adamson wrote:
No mount option - just configure your machine to not load any pnfs layoutdriver modules.
That works, thanks, but I was hoping for a way to have
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layout and non-layout
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mounts going on at the same time.
Different VMs?
Trond
Would there be any objections to adding a "nopnfs" mount option to force this behavior? It could be useful at least for testing, possibly for working around server problems, or if an admin knows that certain clients' usage patterns would be better served by disabling pnfs.
Yes. Why should we be adding debugging mount options to the upstream code? Just test the damned pnfs code properly before it goes upstream...
Trond
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Such a mount option could be useful for dealing with buggy servers (pnfs-wise) so you could mount one server with pnfs and another without.
You can find ways around that. Just use 2 clients: one with pnfs switched on, and one with it off.
I really don't want to introduce mount options upstream unless they are useful in the long term. One off usefulness does not pass that test.
I guess we can live with that for the short term.