XFS in the main kernel
Quoted 20 lines
Re: XFS in the main kernel
From: Luigi Genoni ([email protected])
Quoted 9 lines · Keith Owens
Quoted 7 lines · On 22 Apr 2002 18:55:20 +0200, [email protected] (Wichert Akkerman) wrote:
In article <[email protected]>,
Quoted 4 lines · Dan Yocum
I know it's been discussed to death, but I am making a formal request to you to include XFS in the main kernel. We (The Sloan Digital Sky Survey) and many, many other groups here at Fermilab would be very happy to have this in the main tree.
Quoted 5 lines
Quoted 1 line
Has XFS been proven to be completely stable
As much as any other filesystem. "There are no bugs in filesystem XYZ. That just means that you have not looked hard enough." :) There is a daily QA suite that XFS is run through.
Quoted 6 lines
In the reality the inclusion on XFS in the 2.5 tree would probably move more peole to use it, and so also to eventually trigger bugs, to report them, sometimes to fix them.
This way XFS would improve faster, and of course that would be a good thing.
definitely. Unless XFS is in the mainline kernel (marked as
experimantal if necessary) it will not get good exposure.
The most important (only) reason I do not use it (and recommend our
customers against using it) is that at the moment it is impossible to track both the kernel and XFS at the same time. This is a shame, because I think that for some application XFS is superior to the other alternatives (can be said about the other alternatives to :-).
Quoted 7 lines
That said, it is important to
consider the technical reasons to include XFS in 2.5 or not; if this inclusion could cause some troubles, if XFS fits the requirements Linus asks for the inclusion and what impact the inclusion would have on the kernel (Think to JFS as a good example of an easy inclusion, with low impact).
so, what were the main obstacles again? The VFS layer?
Martin
Signature · 5 lines
------------------------------------------------------------------ Martin Knoblauch | email: [email protected] TeraPort GmbH | Phone: +49-89-510857-309 C+ITS | Fax: +49-89-510857-111 http://www.teraport.de | Mobile: +49-170-4904759
Quoted 29 lines · Martin Knoblauch
Quoted 22 lines
Re: XFS in the main kernel
From: Luigi Genoni ([email protected])
Quoted 11 lines · Keith Owens
Quoted 8 lines · On 22 Apr 2002 18:55:20 +0200, [email protected] (Wichert Akkerman) wrote:
In article <[email protected]>,
Quoted 5 lines · Dan Yocum
I know it's been discussed to death, but I am making a formal request to you to include XFS in the main kernel. We (The Sloan Digital Sky Survey) and many, many other groups here at Fermilab would be very happy to have this in the main tree.
Quoted 6 lines
Quoted 2 lines
Has XFS been proven to be completely stable
As much as any other filesystem. "There are no bugs in filesystem XYZ. That just means that you have not looked hard enough." :) There is a daily QA suite that XFS is run through.
Quoted 6 lines
In the reality the inclusion on XFS in the 2.5 tree would probably move more peole to use it, and so also to eventually trigger bugs, to report them, sometimes to fix them.
This way XFS would improve faster, and of course that would be a good thing.
Quoted 9 lines
definitely. Unless XFS is in the mainline kernel (marked as experimantal if necessary) it will not get good exposure.
The most important (only) reason I do not use it (and recommend our customers against using it) is that at the moment it is impossible to track both the kernel and XFS at the same time. This is a shame, because I think that for some application XFS is superior to the other alternatives (can be said about the other alternatives to :-).
You would be surprised about the level of exposure XFS is getting, a lot more than you might realize. It is in everything from settop boxes and fiber channel switches to NAS boxes, those folks in general do not want to advertise. Here are a few larger scale installations out there:
http://oss.sgi.com/projects/xfs/xfs_users.html
Steve
Quoted 50 lines · Martin Knoblauch
Quoted 23 lines
Re: XFS in the main kernel
From: Luigi Genoni ([email protected])
Quoted 11 lines · Keith Owens
Quoted 8 lines · On 22 Apr 2002 18:55:20 +0200, [email protected] (Wichert Akkerman) wrote:
In article <[email protected]>,
Quoted 5 lines · Dan Yocum
I know it's been discussed to death, but I am making a formal request to you to include XFS in the main kernel. We (The Sloan Digital Sky Survey) and many, many other groups here at Fermilab would be very happy to have this in the main tree.
Quoted 6 lines
Quoted 2 lines
Has XFS been proven to be completely stable
As much as any other filesystem. "There are no bugs in filesystem XYZ. That just means that you have not looked hard enough." :) There is a daily QA suite that XFS is run through.
Quoted 7 lines
In the reality the inclusion on XFS in the 2.5 tree would probably move more peole to use it, and so also to eventually trigger bugs, to report them, sometimes to fix them.
This way XFS would improve faster, and of course that would be a good thing.definitely. Unless XFS is in the mainline kernel (marked as
experimantal if necessary) it will not get good exposure.The most important (only) reason I do not use it (and recommend our
customers against using it) is that at the moment it is impossible to track both the kernel and XFS at the same time. This is a shame, because I think that for some application XFS is superior to the other alternatives (can be said about the other alternatives to :-).Quoted 8 lines
That said, it is important to
consider the technical reasons to include XFS in 2.5 or not; if this inclusion could cause some troubles, if XFS fits the requirements Linus asks for the inclusion and what impact the inclusion would have on the kernel (Think to JFS as a good example of an easy inclusion, with low impact).
Quoted 2 lines
so, what were the main obstacles again? The VFS layer?
The VFS and such features like "delayed block allocation". XFS tries to gather 64K or so before submitting to disk/block layer.
FWIW, SuSE 8 ships with full (but experimental marked) XFS support.
Quoted 22 lines · Stephen Lord
Quoted 10 lines · Martin Knoblauch
definitely. Unless XFS is in the mainline kernel (marked as experimantal if necessary) it will not get good exposure.
The most important (only) reason I do not use it (and recommend our customers against using it) is that at the moment it is impossible to track both the kernel and XFS at the same time. This is a shame, because I think that for some application XFS is superior to the other alternatives (can be said about the other alternatives to :-).
You would be surprised about the level of exposure XFS is getting, a lot more
than you might realize. It is in everything from settop boxes and fiber channel
switches to NAS boxes, those folks in general do not want to advertise. Here are
a few larger scale installations out there:
Quoted 3 lines
http://oss.sgi.com/projects/xfs/xfs_users.html
Steve
Steve,
no question that those are seriour users that give you serious
feedback. And if you call that
exposure, I am not going to argue. It is your project, it is your marketing. (And *I* am not going to argue about SGI marketing :-(
From a mainline point of view XFS on Linux will only be successfull if
it is "in the kernel". Fully maintained and "Linus approved". I am not sure when SGI started the port (could even go back to the time when I worked for them, late 1997). Definitely quite some time. By now it should be in the kernel. Maybe marked "experimental". As I see it now EXT3, ReiserFS and maybe JFS are just eating the XFS lunch away.
In any case, the Vanderbilt comment is right on.
Martin
Signature · 5 lines
------------------------------------------------------------------ Martin Knoblauch | email: [email protected] TeraPort GmbH | Phone: +49-89-510857-309 C+ITS | Fax: +49-89-510857-111 http://www.teraport.de | Mobile: +49-170-4904759
Quoted 5 lines · Peter Wächtler
Quoted 3 lines · Martin Knoblauch
Quoted 2 lines
Re: XFS in the main kernel
Quoted 7 lines
Quoted 2 lines
so, what were the main obstacles again? The VFS layer?
The VFS and such features like "delayed block allocation". XFS tries to gather 64K or so before submitting to disk/block layer.
FWIW, SuSE 8 ships with full (but experimental marked) XFS support.
Definitely a step forward. But some people (including myself, I guess)
do not like distribution kernels. Yeah, hard to please - I know :-). I use SuSE on the desktop, but not because of the kernel. I use RedHat on servers and compute nodes, but not because of the kernel.
Martin
PS: Thanks for the hint. I didn't realize it when I upgraded to 8.0.
Signature · 5 lines
------------------------------------------------------------------ Martin Knoblauch | email: [email protected] TeraPort GmbH | Phone: +49-89-510857-309 C+ITS | Fax: +49-89-510857-111 http://www.teraport.de | Mobile: +49-170-4904759
Quoted 8 lines · On 2002.04.23 Martin Knoblauch wrote:
Quoted 7 lines · Stephen Lord
Quoted 4 lines · Martin Knoblauch
definitely. Unless XFS is in the mainline kernel (marked as experimantal if necessary) it will not get good exposure.
[...]
Quoted 10 lines
From a mainline point of view XFS on Linux will only be successfull if it is "in the kernel". Fully maintained and "Linus approved". I am not sure when SGI started the port (could even go back to the time when I worked for them, late 1997). Definitely quite some time. By now it should be in the kernel. Maybe marked "experimental". As I see it now EXT3, ReiserFS and maybe JFS are just eating the XFS lunch away.
In any case, the Vanderbilt comment is right on.
If XFS is so good (i do not doubt it), I see some issues (plz correct me if I'm wrong...):
- XFS needs substantial changes in the VFS layer to work
- This changes are good (or make xfs so good)
- *THE THING* to do is to integrate this changes in mainline tree VFS, so XFS will stop duplicating half the kernel code.
Why those features are not merged ? Incompatibilities ? Licensing ? Religious wars about some way of doing things ?
Plz, if SGI splits XFS in small chunks and starts feeding linus with changes in the VFS, what will happen ? Why that doesn't happen ?
Just some ideas...
Signature · 4 lines
J.A. Magallon # Let the source be with you... mailto:[email protected] Mandrake Linux release 8.3 (Cooker) for i586 Linux werewolf 2.4.19-pre7-jam6 #2 SMP mar abr 23 16:56:56 CEST 2002 i686
Quoted 4 lines · Martin Knoblauch
Quoted 2 lines
Re: XFS in the main kernel
definitely. Unless XFS is in the mainline kernel (marked as
experimantal if necessary) it will not get good exposure.
XFS needs 2.5, not 2.4, because of a lot of reasons.
If I do remember well a strong obiection to XFS is that it introduces a kernel thread to emulate Irix behavious to talk with pagebuf (a la Irix), end to have an interface with VM and Block Device layer.
This forces some vincles.
It is a lot of time that I do not try XFS, so maybe things changed, but XFS has has data block of the same size of memory pages (4 or 8 Kb depending on architecture), not that I have some remak about that, but I use XFS on Irix on an Origin 2000 with a couple of TB disk space, it is another thing in front of Linux ports.
On the other side delayed allocation is quite cool ;)
Quoted 6 lines
The most important (only) reason I do not use it (and recommend our
customers against using it) is that at the moment it is impossible to track both the kernel and XFS at the same time. This is a shame, because I think that for some application XFS is superior to the other alternatives (can be said about the other alternatives to :-).
Every FS has its strenght points and its weackness.
For example on MC^2 I found reiserFS on LVM to have a really good interaction with the way MC^2 works, expecially because I have a lot of small|medium sized files, I suppose.
I also tied XFS and JFS on MC^2, and maybe with other file size and I/O loads they would be better. I just talk for my systems needs.
(all test were with latest 2.4 kernels, a month ago. I cannot risk corruption on this
storage system, so 2.5 is not for me there :( ).
Quoted 11 lines
Quoted 8 lines
That said, it is important to
consider the technical reasons to include XFS in 2.5 or not; if this inclusion could cause some troubles, if XFS fits the requirements Linus asks for the inclusion and what impact the inclusion would have on the kernel (Think to JFS as a good example of an easy inclusion, with low impact).so, what were the main obstacles again? The VFS layer?
See my previous comments...
Quoted 8 lines · Luigi Genoni
Quoted 4 lines · Martin Knoblauch
Quoted 2 lines
Re: XFS in the main kernel
definitely. Unless XFS is in the mainline kernel (marked as
experimantal if necessary) it will not get good exposure.
Quoted 7 lines
XFS needs 2.5, not 2.4, because of a lot of reasons.
If I do remember well a strong obiection to XFS is that it introduces a kernel thread to emulate Irix behavious to talk with pagebuf (a la Irix), end to have an interface with VM and Block Device layer.This forces some vincles.
No problem with XFS going into 2.5 mainline, but not 2.4. But - is that
happening?
Martin
Signature · 5 lines
------------------------------------------------------------------ Martin Knoblauch | email: [email protected] TeraPort GmbH | Phone: +49-89-510857-309 C+ITS | Fax: +49-89-510857-111 http://www.teraport.de | Mobile: +49-170-4904759
Quoted 14 lines · Martin Knoblauch
Quoted 13 lines · Luigi Genoni
Quoted 4 lines · Martin Knoblauch
Quoted 2 lines
Re: XFS in the main kernel
definitely. Unless XFS is in the mainline kernel (marked as
experimantal if necessary) it will not get good exposure.XFS needs 2.5, not 2.4, because of a lot of reasons.
If I do remember well a strong obiection to XFS is that it introduces a kernel thread to emulate Irix behavious to talk with pagebuf (a la Irix), end to have an interface with VM and Block Device layer.
Quoted 6 lines
Quoted 2 lines
This forces some vincles.
No problem with XFS going into 2.5 mainline, but not 2.4. But - is that
happening?
I do not think so. At the end it is Linus the one who should decide, and XFS should find a way to agree with him. All depends on this.
Quoted 11 lines · J.A. Magallon
On 2002.04.23 Martin Knoblauch wrote:
If XFS is so good (i do not doubt it), I see some issues (plz correct me if I'm wrong...):- XFS needs substantial changes in the VFS layer to work
- This changes are good (or make xfs so good)
- *THE THING* to do is to integrate this changes in mainline tree VFS, so XFS will stop duplicating half the kernel code.Why those features are not merged ? Incompatibilities ? Licensing ? Religious wars about some way of doing things ?
No. It's simply a matter of nobody having done the required analysis to find a really good way to reconcile XFS's way of doing things with mainline vfs. This is time-consuming work that requires a good deal of skill, and right now there are many projects in the same category.
My advice to anyone who wants to make it go faster? Jump in and start doing the analysis (start with xfs/pagebuf.c). If you are a company who wants it to go faster, try offering money. Otherwise, it goes at its own speed, and this work will likely come up to the top of the pile later in the 2.5 cycle.
Signature · 1 line
Daniel
Quoted 3 lines · Luigi Genoni
If I do remember well a strong obiection to XFS is that it introduces a kernel thread to emulate Irix behavious to talk with pagebuf (a la Irix), end to have an interface with VM and Block Device layer.
There is nothing wrong with a filesystem having its own management thread - this seems to be a feature of all the new filesystems. How that thread interacts with vm and the vfs is an open question, not answered very well by any filesystem at the moment, let alone XFS. Bottom line: XFS's thread is not the issue.
Signature · 1 line
Daniel
It also depends on what XFS guys want to do.
They are probably confortable with this sort of interface so that XFS works de facto like if it has to do with Irix.
To go to Linux VFS will be a lot of work for them I think.
Quoted 32 lines · Daniel Phillips
Quoted 11 lines · J.A. Magallon
On 2002.04.23 Martin Knoblauch wrote:
If XFS is so good (i do not doubt it), I see some issues (plz correct me if I'm wrong...):- XFS needs substantial changes in the VFS layer to work
- This changes are good (or make xfs so good)
- *THE THING* to do is to integrate this changes in mainline tree VFS, so XFS will stop duplicating half the kernel code.Why those features are not merged ? Incompatibilities ? Licensing ? Religious wars about some way of doing things ?
No. It's simply a matter of nobody having done the required analysis to find a really good way to reconcile XFS's way of doing things with mainline vfs. This is time-consuming work that requires a good deal of skill, and right now there are many projects in the same category.
My advice to anyone who wants to make it go faster? Jump in and start doing the analysis (start with
xfs/pagebuf.c). If you are a company who wants it to go faster, try offering money. Otherwise, it goes at its own speed, and this work will likely come up to the top of the pile later in the 2.5 cycle.--
Daniel
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