* dmapi support for reiser4 @ 2005-06-28 9:34 Bjoern JACKE 2005-06-28 11:31 ` Vladimir Saveliev 0 siblings, 1 reply; 9+ messages in thread From: Bjoern JACKE @ 2005-06-28 9:34 UTC (permalink / raw) To: reiserfs-list Hi, DMAPI support is a feature which is essential for usage in many important environments. Are there any plans to add dmapi support to reiser4 ? Bjoern ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: dmapi support for reiser4 2005-06-28 9:34 dmapi support for reiser4 Bjoern JACKE @ 2005-06-28 11:31 ` Vladimir Saveliev 2005-06-29 11:57 ` Bjoern JACKE 0 siblings, 1 reply; 9+ messages in thread From: Vladimir Saveliev @ 2005-06-28 11:31 UTC (permalink / raw) To: Bjoern JACKE; +Cc: reiserfs-list Hello On Tue, 2005-06-28 at 13:34, Bjoern JACKE wrote: > Hi, > > DMAPI support is a feature which is essential for usage in many > important environments. Are there any plans to add dmapi support to > reiser4 ? > there is no currently > Bjoern > ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: dmapi support for reiser4 2005-06-28 11:31 ` Vladimir Saveliev @ 2005-06-29 11:57 ` Bjoern JACKE 2005-06-29 16:15 ` Vladimir Saveliev ` (2 more replies) 0 siblings, 3 replies; 9+ messages in thread From: Bjoern JACKE @ 2005-06-29 11:57 UTC (permalink / raw) To: Vladimir Saveliev; +Cc: reiserfs-list On 2005-06-28 at 15:31 +0400 Vladimir Saveliev sent off: >> DMAPI support is a feature which is essential for usage in many >> important environments. Are there any plans to add dmapi support to >> reiser4 ? >> >there is no currently would be very nice to have that, one day reiser4 has survived all the troubleful discussion about kernel integration it is in right now. DMAPI is really a feature which is a must-have for big setups. One of the reasons is file allocation info which is retrievable which makes sparse file handling efficient. Of course there are much more useful posibilities DMAPI gives to get over POSIX limitation. XFS, JFS2, GPFS, Veritas filesystem for Solaris, they all have DMAPI support and reiser4 will not be a real competitor without this. I hope it will come one day ... Bjoern ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: dmapi support for reiser4 2005-06-29 11:57 ` Bjoern JACKE @ 2005-06-29 16:15 ` Vladimir Saveliev 2005-06-29 16:32 ` Bjoern JACKE 2005-06-29 22:41 ` Chet Hosey 2005-06-30 3:07 ` Hans Reiser 2 siblings, 1 reply; 9+ messages in thread From: Vladimir Saveliev @ 2005-06-29 16:15 UTC (permalink / raw) To: Bjoern JACKE; +Cc: reiserfs-list Hello On Wed, 2005-06-29 at 15:57, Bjoern JACKE wrote: > On 2005-06-28 at 15:31 +0400 Vladimir Saveliev sent off: > >> DMAPI support is a feature which is essential for usage in many > >> important environments. Are there any plans to add dmapi support to > >> reiser4 ? > >> > >there is no currently > > would be very nice to have that, one day reiser4 has survived all the > troubleful discussion about kernel integration it is in right now. > DMAPI is really a feature which is a must-have for big setups. One of > the reasons is file allocation info which is retrievable which makes > sparse file handling efficient. Of course there are much more useful > posibilities DMAPI gives to get over POSIX limitation. XFS, JFS2, > GPFS, Veritas filesystem for Solaris, they all have DMAPI support > and reiser4 will not be a real competitor without this. I hope it > will come one day ... > I would guess that it is rather operating system feature than a filesystem one. Can you please point some source of information about DMAPI? > Bjoern > ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: dmapi support for reiser4 2005-06-29 16:15 ` Vladimir Saveliev @ 2005-06-29 16:32 ` Bjoern JACKE 0 siblings, 0 replies; 9+ messages in thread From: Bjoern JACKE @ 2005-06-29 16:32 UTC (permalink / raw) To: Vladimir Saveliev; +Cc: reiserfs-list Hi, On 2005-06-29 at 20:15 +0400 Vladimir Saveliev sent off: >I would guess that it is rather operating system feature than a >filesystem one. Can you please point some source of information about >DMAPI? the main part is to be done by the filesystem, the OS cannot do everything by itself, there a plenty of things which just the filesystem can do by itself. Here are some links: http://www.opengroup.org/onlinepubs/9657099/ http://www.computer.org/conferences/mss95/lawthers/lawthers.htm http://www.csu.edu.au/special/auugwww96/proceedings/alex/alex.html You can also take a look at the XFS and JFS source code parts of dmapi to get an impression of what is to be done for it at fs layer. Bjoern ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: dmapi support for reiser4 2005-06-29 11:57 ` Bjoern JACKE 2005-06-29 16:15 ` Vladimir Saveliev @ 2005-06-29 22:41 ` Chet Hosey 2005-06-30 7:12 ` Ragnar Kjørstad 2005-06-30 3:07 ` Hans Reiser 2 siblings, 1 reply; 9+ messages in thread From: Chet Hosey @ 2005-06-29 22:41 UTC (permalink / raw) To: Bjoern JACKE; +Cc: reiserfs-list Bjoern JACKE wrote: > Hi, > On 2005-06-29 at 20:15 +0400 Vladimir Saveliev sent off: > >> I would guess that it is rather operating system feature than a >> filesystem one. Can you please point some source of information about >> DMAPI? > > > the main part is to be done by the filesystem, the OS cannot do > everything by itself, there a plenty of things which just the > filesystem can do by itself. Here are some links: > > http://www.opengroup.org/onlinepubs/9657099/ > http://www.computer.org/conferences/mss95/lawthers/lawthers.htm > http://www.csu.edu.au/special/auugwww96/proceedings/alex/alex.html > > You can also take a look at the XFS and JFS source code parts of dmapi > to get > an impression of what is to be done for it at fs layer. > > Bjoern Is there a standard VFS interface that these filesystems present, or is it done via filesystem-specific extensions? If the latter, perhaps you should consider submitting a kernel patch that adds the required interface to the VFS layer, and note in your submission that XFS and JFS aren't compliant. How is DMAPI different from FAM with an extra API function for creating explicit holes? You said that "reiser4 will not be a real competitor without this". A competitor in what market? Can you name an application that depends on DMAPI and is so important that without that particular application Reiser4 is not appropriate for storing files? I note that the second link you provided is ten years old, nearly to the day. The third is nine years old.I'm not suggesting that you're overstating the importance of DMAPI, but why do you think that something so important might have been overlooked for so long? Novell just switched to Reiserfs as their default SUSE filesystem. If Reiserfs isn't a "real competitor" without DMAPI, why would they do something so unwise? Just curious, as I'd not heard of DMAPI prior to your post, but you claim it's quite important. -- chet ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: dmapi support for reiser4 2005-06-29 22:41 ` Chet Hosey @ 2005-06-30 7:12 ` Ragnar Kjørstad 2005-06-30 11:42 ` Chet Hosey 0 siblings, 1 reply; 9+ messages in thread From: Ragnar Kjørstad @ 2005-06-30 7:12 UTC (permalink / raw) To: Chet Hosey; +Cc: Bjoern JACKE, reiserfs-list On Wed, Jun 29, 2005 at 06:41:46PM -0400, Chet Hosey wrote: > >> I would guess that it is rather operating system feature than a > >> filesystem one. Can you please point some source of information about > >> DMAPI? > > Is there a standard VFS interface that these filesystems present, or is > it done via filesystem-specific extensions? If the latter, perhaps you > should consider submitting a kernel patch that adds the required > interface to the VFS layer, and note in your submission that XFS and JFS > aren't compliant. The OpenXDSM project intended to extend the VFS layer with a few extra functions and to implement a generic XDSM/DMAPI layer on top of that. The project never really got anywhere and the sourceforge webpage has been removed, but you can still find some pointers to the VFS discussions if you google for OpenXDSM. In short, the filesystems needed to be extended with functionality in two primary areas: - persistent storage of metadata - beeing able to punch holes in existing files. The first item has since been solved by extended attributes, and I believe there were some ideas about how to change truncate to also be able to punch holes. There were probably a few more things needed to be done, but I don't remember. Google probably knows. > You said that "reiser4 will not be a real competitor without this". A > competitor in what market? Can you name an application that depends on > DMAPI and is so important that without that particular application > Reiser4 is not appropriate for storing files? DMAPI is used for Hirarchial Storage Management, migrating unused files to slower medium such as tape. It can also be used by backupsystems. I should add though, that not everybody that does HSM are big fans of DMAPI. It's quite possible that it would be just as productive to add a _different_ API for HSM to linux as adding DMAPI. > Just curious, as I'd not heard of DMAPI prior to your post, but you > claim it's quite important. It is important in a relatively narrow (high end) market, not really for desktops and low end servers. -- Ragnar Kjørstad ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: dmapi support for reiser4 2005-06-30 7:12 ` Ragnar Kjørstad @ 2005-06-30 11:42 ` Chet Hosey 0 siblings, 0 replies; 9+ messages in thread From: Chet Hosey @ 2005-06-30 11:42 UTC (permalink / raw) To: reiserfs-list Ragnar Kjørstad wrote: >On Wed, Jun 29, 2005 at 06:41:46PM -0400, Chet Hosey wrote: > > >>Is there a standard VFS interface that these filesystems present, or is >>it done via filesystem-specific extensions? If the latter, perhaps you >>should consider submitting a kernel patch that adds the required >>interface to the VFS layer, and note in your submission that XFS and JFS >>aren't compliant. >> >> > >The OpenXDSM project intended to extend the VFS layer with a few extra >functions and to implement a generic XDSM/DMAPI layer on top of that. > >The project never really got anywhere and the sourceforge webpage has >been removed, but you can still find some pointers to the VFS >discussions if you google for OpenXDSM. > > > In short, no, there's no standard VFS implementation. Gotcha. >In short, the filesystems needed to be extended with functionality in >two primary areas: >- persistent storage of metadata >- beeing able to punch holes in existing files. > >The first item has since been solved by extended attributes, and I >believe there were some ideas about how to change truncate to also be >able to punch holes. There were probably a few more things needed to be >done, but I don't remember. Google probably knows. > > So essentially you're looking for an interface by which you can produce holes in files? That sounds like a minor feature request, certainly one without which a filesystem might still be a "real competitor" in a general market. >>You said that "reiser4 will not be a real competitor without this". A >>competitor in what market? Can you name an application that depends on >>DMAPI and is so important that without that particular application >>Reiser4 is not appropriate for storing files? >> >> > >DMAPI is used for Hirarchial Storage Management, migrating unused files >to slower medium such as tape. It can also be used by backupsystems. > >I should add though, that not everybody that does HSM are big fans of >DMAPI. It's quite possible that it would be just as productive to add a >_different_ API for HSM to linux as adding DMAPI. > > > Let me clarify -- you made claims that reiser4 isn't a "real competitor" without DMAPI. Specifically, DMAPI. I asked whether you can name a DMAPI-dependent application which *must* work on a given filesystem in order for it to be a "real competitor". You haven't thus far. Now you're saying, well, not necessarily DMAPI, but *something*.You're being vague. To publicly claim that Reiser4 isn't a "real competitor" without your-favorite-buzzword without providing some *actual evidence* as to why this is the case seems a little bit rude. Can you support your accusations? >>Just curious, as I'd not heard of DMAPI prior to your post, but you >>claim it's quite important. >> >> > >It is important in a relatively narrow (high end) market, not really for >desktops and low end servers. > > > Again, I'd consider it polite to either clarify or adjust your claims that Reiser4 isn't a "real competitor" (note that you didn't initially name *any* market, you just made a broad statement that Reiser4 can't compete). -- chet ^ permalink raw reply [flat|nested] 9+ messages in thread
* Re: dmapi support for reiser4 2005-06-29 11:57 ` Bjoern JACKE 2005-06-29 16:15 ` Vladimir Saveliev 2005-06-29 22:41 ` Chet Hosey @ 2005-06-30 3:07 ` Hans Reiser 2 siblings, 0 replies; 9+ messages in thread From: Hans Reiser @ 2005-06-30 3:07 UTC (permalink / raw) To: Bjoern JACKE; +Cc: Vladimir Saveliev, reiserfs-list Bjoern JACKE wrote: > On 2005-06-28 at 15:31 +0400 Vladimir Saveliev sent off: > >>> DMAPI support is a feature which is essential for usage in many >>> important environments. Are there any plans to add dmapi support to >>> reiser4 ? >>> >> there is no currently > > > would be very nice to have that, one day reiser4 has survived all the > troubleful discussion about kernel integration it is in right now. > DMAPI is really a feature which is a must-have for big setups. One of > the reasons is file allocation info which is retrievable which makes > sparse file handling efficient. Of course there are much more useful > posibilities DMAPI gives to get over POSIX limitation. XFS, JFS2, > GPFS, Veritas filesystem for Solaris, they all have DMAPI support and > reiser4 will not be a real competitor without this. I hope it will > come one day ... > > Bjoern > > All it requires is money...... :-/ If you have some knowledge of someone who might fund it, let me know. ^ permalink raw reply [flat|nested] 9+ messages in thread
end of thread, other threads:[~2005-06-30 11:42 UTC | newest] Thread overview: 9+ messages (download: mbox.gz follow: Atom feed -- links below jump to the message on this page -- 2005-06-28 9:34 dmapi support for reiser4 Bjoern JACKE 2005-06-28 11:31 ` Vladimir Saveliev 2005-06-29 11:57 ` Bjoern JACKE 2005-06-29 16:15 ` Vladimir Saveliev 2005-06-29 16:32 ` Bjoern JACKE 2005-06-29 22:41 ` Chet Hosey 2005-06-30 7:12 ` Ragnar Kjørstad 2005-06-30 11:42 ` Chet Hosey 2005-06-30 3:07 ` Hans Reiser
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