Hi Jan, sorry to borther you, but I need some info and you are propably the best one to answer. I am planing now a new backup system (servers) for a medical company. My idea is to have a dedicated backup server in each building and wia two way mirror mirror it to another server in diff building (bacause of security) through fs. ZFS is capable, but i would like to stick to a Linux. As I understand, there is some work done in two way mirror in brtfs (which seems to me as best solustion for that under linux) and you are the one working on that. My Qs are: - do you know any better fs for this purpose, other than brtfs under Linux? - What is the implementation of two way mirror in brtfs, and when do you expect to have it done to a degree so I can try it? Tt does not have to work now, but it should work next year ;O) I have 20years experience in linux, and if I do not have to debug anything, I am more less happy ;O) Thank you very much! Jaromir -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Sorry fo the typo in the subject! Just to add, I would like to see a two way mirror solution, but if it will not work now/is not implemnted yet, I would propably choose between drbd in asynchronous mode or make a some kind if "incremental" snapshot to a remote mapped disk (I do not know yet, if brtfs support it) - it means have one shapshop and let''s say have a daily incremental update of this snapshot. How would you do it? I have never used btrfs, baucause in "brtfs home page" is still written experimental, and lately with three kids I have less and less time to experiment ... but, as I found some short time ago, there is laso a suggestion to use it ... and I know it is used more and more frequently ... so i will give it a try. Btw when is a plan to move it from experimental? ;o) Have to look at the source code a bit (hope there are some notes about future). Jaromir> ------------ Původní zpráva ------------ > Od: Jaromir Zdrazil <jaromir.zdrazil@email.cz> > Předmět: Who way mirror in BRTFS > Datum: 30.12.2011 12:55:44 > ---------------------------------------- > Hi Jan, > > sorry to borther you, but I need some info and you are propably the best one > to answer. > > I am planing now a new backup system (servers) for a medical company. My idea > is to have a dedicated backup server in each building and wia two way mirror > mirror it to another server in diff building (bacause of security) through fs. > ZFS is capable, but i would like to stick to a Linux. > As I understand, there is some work done in two way mirror in brtfs (which > seems to me as best solustion for that under linux) and you are the one working > on that. > > My Qs are: > - do you know any better fs for this purpose, other than brtfs under Linux? > - What is the implementation of two way mirror in brtfs, and when do you expect > to have it done to a degree so I can try it? Tt does not have to work now, but > it should work next year ;O) > > I have 20years experience in linux, and if I do not have to debug anything, I am > more less happy ;O) > > Thank you very much! Jaromir > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html-- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
2011/12/30 Jaromir Zdrazil <jaromir.zdrazil@email.cz>:> Sorry fo the typo in the subject! > > Just to add, I would like to see a two way mirror solution, but if it will not work now/is not implemnted yet, I would propably choose between drbd in asynchronous mode or make a some kind if "incremental" snapshot to a remote mapped disk (I do not know yet, if brtfs support it) - it means have one shapshop and let''s say have a daily incremental update of this snapshot.You mean like "zfs send -i"? If yes, why not just use zfs? There''s zfsonlinux project, with easy-to-install ppa for ubuntu. Or you could compile it manually.> > How would you do it?If you DO mean zfs-send-like-functionality, then you should ask about "btrfs send and receive", not "two way mirror" (which is not an accurate way to describe what you want). Also, send/receive ability does not mean it can act as two-way mirror. It CAN be an alternative to drbd async though. I don''t think there''s any publicly available code for it yet though. -- Fajar -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> ------------ Původní zpráva ------------ > Od: Fajar A. Nugraha <list@fajar.net> > Předmět: Re: Two way mirror in BRTFS > Datum: 30.12.2011 14:27:39 > ---------------------------------------- > 2011/12/30 Jaromir Zdrazil <jaromir.zdrazil@email.cz>: > > Sorry fo the typo in the subject! > > > > Just to add, I would like to see a two way mirror solution, but if it will not > work now/is not implemnted yet, I would propably choose between drbd in > asynchronous mode or make a some kind if "incremental" snapshot to a remote > mapped disk (I do not know yet, if brtfs support it) - it means have one > shapshop and let''s say have a daily incremental update of this snapshot. > > You mean like "zfs send -i"? If yes, why not just use zfs? There''s > zfsonlinux project, with easy-to-install ppa for ubuntu. Or you could > compile it manually. >Thank you for your suggestion. As I know, there is not everything ported yet, and one of the missing important features I plan to use is to crypt fs. And if I am not mistaken, current version does not yet support a mountable filesystem.> > > > How would you do it? > > If you DO mean zfs-send-like-functionality, then you should ask about > "btrfs send and receive", not "two way mirror" (which is not an > accurate way to describe what you want). Also, send/receive ability > does not mean it can act as two-way mirror. It CAN be an alternative > to drbd async though.If I understand it correctly, the diff between send and receive and two way mirror is that one is synchronous and the other is not (sends the signal that the file have been succesfully written after all/one instance have been succesfully written). Maybe you can explain it a bit more.> > I don''t think there''s any publicly available code for it yet though. >Thank you. Jaromir> -- > Fajar > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html-- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
2011/12/30 Jaromir Zdrazil <jaromir.zdrazil@email.cz>:>> > Just to add, I would like to see a two way mirror solution, but if it will not >> work now/is not implemnted yet, I would propably choose between drbd in >> asynchronous mode or make a some kind if "incremental" snapshot to a remote >> mapped disk (I do not know yet, if brtfs support it) - it means have one >> shapshop and let''s say have a daily incremental update of this snapshot. >> >> You mean like "zfs send -i"? If yes, why not just use zfs? There''s >> zfsonlinux project, with easy-to-install ppa for ubuntu. Or you could >> compile it manually. >> > Thank you for your suggestion. As I know, there is not everything ported yet, and one of the missing important features I plan to use is to crypt fs.correct. But btrfs doesn''t do encryption as well. And if you''re thinking of using luks/dm-crupt to provide encryption for btrfs, there''s nothing preventing you to use the same thing with zfs.> And if I am not mistaken, current version does not yet support a mountable filesystem.You''re mistaken :) With some extra work, you can even use it as root: - http://zfsonlinux.org/example-zpl.html - https://github.com/dajhorn/pkg-zfs/wiki/HOWTO-install-Ubuntu-to-a-Native-ZFS-Root-Filesystem>> > >> > How would you do it? >> >> If you DO mean zfs-send-like-functionality, then you should ask about >> "btrfs send and receive", not "two way mirror" (which is not an >> accurate way to describe what you want). Also, send/receive ability >> does not mean it can act as two-way mirror. It CAN be an alternative >> to drbd async though. > > If I understand it correctly, the diff between send and receive and two way mirror is that one is synchronous and the other is not (sends the signal that the file have been succesfully written after all/one instance have been succesfully written). > Maybe you can explain it a bit more.Two way: A replicates changes to B, and B can replicate it''s own changes to A One way: A replicates changes to B, but B can not replicate it''s own changes to A While drbd only supports synchronous mode for active-active setup, the generic "two way replication" does not have to be so. Also, just because something is synchronous does not automatically mean it supports two-way replication. Either way, neither zfs or the (planned) btrfs send/receive supports two-way/active-active setup. Both should (or will) work just fine for one-way replication. -- Fajar -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
>> >> You mean like "zfs send -i"? If yes, why not just use zfs? There''s >> zfsonlinux project, with easy-to-install ppa for ubuntu. Or you could >> compile it manually. >> > Thank you for your suggestion. As I know, there is not everything ported > yet, and one of the missing important features I plan to use is to crypt > fs. And if I am not mistaken, current version does not yet support a > mountable filesystem.You are mistaken :) The current version is pretty stable, as long as you don''t use compression or dedup. Some problems have been reported with weird setups (USB disks for example), but I haven''t seen any reports of unrecoverable filesystems. For btrfs bugs are still fixed on a daily basis, and some reports of people with corrupted and unrecoverable filesystems. Neither supports encryption. I might consider ZFS for a production environment (although it''s officially not production ready), but I don''t think btrfs is ready for that yet. If you want to be safe, use ext4 with drbd or rsync. Niels -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> ------------ Původní zpráva ------------ > Od: Fajar A. Nugraha <list@fajar.net> > Předmět: Re: Re: Two way mirror in BRTFS > Datum: 30.12.2011 15:34:02 > ---------------------------------------- > 2011/12/30 Jaromir Zdrazil <jaromir.zdrazil@email.cz>: > >> > Just to add, I would like to see a two way mirror solution, but if it will > not > >> work now/is not implemnted yet, I would propably choose between drbd in > >> asynchronous mode or make a some kind if "incremental" snapshot to a remote > >> mapped disk (I do not know yet, if brtfs support it) - it means have one > >> shapshop and let''s say have a daily incremental update of this snapshot. > >> > >> You mean like "zfs send -i"? If yes, why not just use zfs? There''s > >> zfsonlinux project, with easy-to-install ppa for ubuntu. Or you could > >> compile it manually. > >> > > Thank you for your suggestion. As I know, there is not everything ported yet, > and one of the missing important features I plan to use is to crypt fs. > > correct. But btrfs doesn''t do encryption as well.I thought it does. Hmm, don''t know why ;O)> And if you''re thinking of using luks/dm-crupt to provide encryption > for btrfs, there''s nothing preventing you to use the same thing with > zfs. > > > And if I am not mistaken, current version does not yet support a mountable > filesystem. > > You''re mistaken :) With some extra work, you can even use it as root: > - http://zfsonlinux.org/example-zpl.html > - > https://github.com/dajhorn/pkg-zfs/wiki/HOWTO-install-Ubuntu-to-a-Native-ZFS-Root-Filesystem >It seems I trust the web pages too much - in http://zfsonlinux.org/ is written that it does not ;O)) otherwise I would be using it already.> >> > > >> > How would you do it? > >> > >> If you DO mean zfs-send-like-functionality, then you should ask about > >> "btrfs send and receive", not "two way mirror" (which is not an > >> accurate way to describe what you want). Also, send/receive ability > >> does not mean it can act as two-way mirror. It CAN be an alternative > >> to drbd async though. > > > > If I understand it correctly, the diff between send and receive and two way > mirror is that one is synchronous and the other is not (sends the signal that > the file have been succesfully written after all/one instance have been > succesfully written). > > Maybe you can explain it a bit more. > > Two way: A replicates changes to B, and B can replicate it''s own changes to A > One way: A replicates changes to B, but B can not replicate it''s own > changes to A >Of course.> While drbd only supports synchronous mode for active-active setup, the > generic "two way replication" does not have to be so. Also, just > because something is synchronous does not automatically mean it > supports two-way replication. >Correct.> Either way, neither zfs or the (planned) btrfs send/receive supports > two-way/active-active setup. Both should (or will) work just fine for > one-way replication. >That is what I needed to know! Thank you very much! Jaromir> -- > Fajar > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html-- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> For btrfs bugs are still fixed on a daily basis, and some reports of > people with corrupted and unrecoverable filesystems.I don''t know that there''s been any actual unrecoverable filesystems recently; unmountable is by far the more common issue, and given that most sane people aren''t putting their only copy of important information on btrfs filesystems, their preference tends to be towards wiping and starting over rather than spending a week to recover the information by hand (the recovery tools that exist are the results of the few who chose the other option). I think "... people with corrupted and not easily recoverable" would be a better summary. -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
>> For btrfs bugs are still fixed on a daily basis, and some reports of >> people with corrupted and unrecoverable filesystems. > > I don''t know that there''s been any actual unrecoverable filesystems > recently; unmountable is by far the more common issue, and given that > most sane people aren''t putting their only copy of important > information on btrfs filesystems, their preference tends to be towards > wiping and starting over rather than spending a week to recover the > information by hand (the recovery tools that exist are the results of > the few who chose the other option). > > I think "... people with corrupted and not easily recoverable" would > be a better summary.Yes, you are right, in most cases most/all of the data is recoverable. There was this case: http://article.gmane.org/gmane.comp.file-systems.btrfs/14755 But that one might be recoverable as well. I''m sure btrfs will become the main linux filesystem of the future, it''s just not there yet. The mythical btrfsck might change this. But neither btrfs or zfs on linux should currently be used for important production systems. Niels -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> It seems I trust the web pages too much - in http://zfsonlinux.org/ is > written that it does not ;O)) otherwise I would be using it already.From the website: Please keep in mind the current 0.5.2 stable release does not yet support a mountable filesystem. This functionality is currently available only in the 0.6.0-rc6 release candidate. Seems clear to me :) Niels -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
2011/12/30 Jaromir Zdrazil <jaromir.zdrazil@email.cz>:>> > And if I am not mistaken, current version does not yet support a mountable >> filesystem. >> >> You''re mistaken :) With some extra work, you can even use it as root: >> - http://zfsonlinux.org/example-zpl.html >> - >> https://github.com/dajhorn/pkg-zfs/wiki/HOWTO-install-Ubuntu-to-a-Native-ZFS-Root-Filesystem >> > It seems I trust the web pages too much - in http://zfsonlinux.org/ is written that it does not ;O)) otherwise I would be using it already.The web page is correct. http://zfsonlinux.org/: "Please keep in mind the current 0.5.2 stable release does not yet support a mountable filesystem. This functionality is currently available only in the 0.6.0-rc6 release candidate." http://zfsonlinux.org/example-zpl.html: "However, all the core functionality is in place and most of the advanced features are working. Stability of the latest release candidates has been very good and performance is respectible. Many people are successfully using the ZFS on Linux release candidates." Most zfsonlinux users use 0.6.0-rc6, and a big part of those is using the easy-to-install package from ubuntu ppa.>> Either way, neither zfs or the (planned) btrfs send/receive supports >> two-way/active-active setup. Both should (or will) work just fine for >> one-way replication. >> > That is what I needed to know! Thank you very much!You''re welcome. -- Fajar -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
> ------------ Původní zpráva ------------ > Od: Niels de Carpentier <niels@decarpentier.com> > Předmět: Re: Re: Two way mirror in BRTFS > Datum: 30.12.2011 16:15:51 > ---------------------------------------- > >> > >> You mean like "zfs send -i"? If yes, why not just use zfs? There''s > >> zfsonlinux project, with easy-to-install ppa for ubuntu. Or you could > >> compile it manually. > >> > > Thank you for your suggestion. As I know, there is not everything ported > > yet, and one of the missing important features I plan to use is to crypt > > fs. And if I am not mistaken, current version does not yet support a > > mountable filesystem. > > You are mistaken :) The current version is pretty stable, as long as you > don''t use compression or dedup. Some problems have been reported with > weird setups (USB disks for example), but I haven''t seen any reports of > unrecoverable filesystems. >Thank you for the info. What I wanted from the fs was 108% acuracy, crypt fs, at least some kind one way mirror, two way would be best and compression of the fs would be nice. Now it seems, that neither of the fsses cancrypt under linux, ZFS is accurate&can reconstruct, BTRFS is accurate&can reconstruct only in mirror, BTRFS can make live incremental backups/snapshots, ZFS can make also send ... and one or two way mirror are future plans for linux ;O)> For btrfs bugs are still fixed on a daily basis, and some reports of > people with corrupted and unrecoverable filesystems. > > Neither supports encryption. > > I might consider ZFS for a production environment (although it''s > officially not production ready), but I don''t think btrfs is ready for > that yet. If you want to be safe, use ext4 with drbd or rsync. > > Niels >Hmm, I have concluded this afternoon, than ZFS under linux does not have what I would like to have, but there seems no better solution under linux for now ... thanks for your experience! It helps me a lot. Jaromir> > > -- > To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html-- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html