* About the state of Btrfs RAID 5/6 @ 2020-09-02 15:10 Neal Gompa 2020-09-02 17:37 ` Josef Bacik 0 siblings, 1 reply; 8+ messages in thread From: Neal Gompa @ 2020-09-02 15:10 UTC (permalink / raw) To: Btrfs BTRFS; +Cc: David Sterba, Robbie Ko, Zygo Blaxell Hey all, It keeps coming up over and over: "Btrfs RAID 5/6 is bad, therefore Btrfs is bad". I know in practice that most people don't use the raid56 modes for various reasons that are unrelated to this, but it's frustrating and annoying that it keeps coming up. I know that Zygo recently posted about how to use RAID 5/6 successfully(-ish)[1], and previously David Sterba tried to work on this[2]. The result of that was the new raid1cX modes, but we still have the raid56 modes. What's holding back Btrfs raid56 from having its status[3] updated from "Unstable" to "mostly OK" or even "OK"? I know that Synology NAS devices use Btrfs and support raid56 using mdraid, why not fix the native RAID features so that layer can be dropped? [1]: https://lore.kernel.org/linux-btrfs/20200627032414.GX10769@hungrycats.org/ [2]: https://hackweek.suse.com/17/projects/do-something-about-btrfs-and-raid56 [3]: https://btrfs.wiki.kernel.org/index.php/Status -- 真実はいつも一つ！/ Always, there's only one truth! ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: About the state of Btrfs RAID 5/6 2020-09-02 15:10 About the state of Btrfs RAID 5/6 Neal Gompa @ 2020-09-02 17:37 ` Josef Bacik 2020-09-02 18:18 ` Neal Gompa 2020-09-03 7:34 ` Johannes Thumshirn 0 siblings, 2 replies; 8+ messages in thread From: Josef Bacik @ 2020-09-02 17:37 UTC (permalink / raw) To: Neal Gompa, Btrfs BTRFS; +Cc: David Sterba, Robbie Ko, Zygo Blaxell On 9/2/20 11:10 AM, Neal Gompa wrote: > Hey all, > > It keeps coming up over and over: "Btrfs RAID 5/6 is bad, therefore > Btrfs is bad". I know in practice that most people don't use the > raid56 modes for various reasons that are unrelated to this, but it's > frustrating and annoying that it keeps coming up. > > I know that Zygo recently posted about how to use RAID 5/6 > successfully(-ish)[1], and previously David Sterba tried to work on > this[2]. The result of that was the new raid1cX modes, but we still > have the raid56 modes. > > What's holding back Btrfs raid56 from having its status[3] updated > from "Unstable" to "mostly OK" or even "OK"? I know that Synology NAS > devices use Btrfs and support raid56 using mdraid, why not fix the > native RAID features so that layer can be dropped? > Honestly there's just a lot of things that need to be looked at right now. Poor Zygo is waiting on the delayed refs flushing work I did months ago because I still haven't gotten back to fixing relocation. At the moment my core priority is getting all the normal parts of the file system working properly, and I've got probably 18 months of hell left before I feel like I'll be able to look up and address the multi-disk aspect of btrfs. RAID0/1/cX modes all work well and are well understood, and that feels "good enough" to me for right now. I know Johannes is working on something magical, but IDK what it is or how far out it is. Thanks, Josef ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: About the state of Btrfs RAID 5/6 2020-09-02 17:37 ` Josef Bacik @ 2020-09-02 18:18 ` Neal Gompa 2020-09-03 7:34 ` Johannes Thumshirn 1 sibling, 0 replies; 8+ messages in thread From: Neal Gompa @ 2020-09-02 18:18 UTC (permalink / raw) To: Josef Bacik Cc: Btrfs BTRFS, David Sterba, Robbie Ko, Zygo Blaxell, Johannes Thumshirn, Chris Murphy On Wed, Sep 2, 2020 at 1:37 PM Josef Bacik <josef@toxicpanda.com> wrote: > > On 9/2/20 11:10 AM, Neal Gompa wrote: > > Hey all, > > > > It keeps coming up over and over: "Btrfs RAID 5/6 is bad, therefore > > Btrfs is bad". I know in practice that most people don't use the > > raid56 modes for various reasons that are unrelated to this, but it's > > frustrating and annoying that it keeps coming up. > > > > I know that Zygo recently posted about how to use RAID 5/6 > > successfully(-ish)[1], and previously David Sterba tried to work on > > this[2]. The result of that was the new raid1cX modes, but we still > > have the raid56 modes. > > > > What's holding back Btrfs raid56 from having its status[3] updated > > from "Unstable" to "mostly OK" or even "OK"? I know that Synology NAS > > devices use Btrfs and support raid56 using mdraid, why not fix the > > native RAID features so that layer can be dropped? > > > > Honestly there's just a lot of things that need to be looked at right now. Poor > Zygo is waiting on the delayed refs flushing work I did months ago because I > still haven't gotten back to fixing relocation. > > At the moment my core priority is getting all the normal parts of the file > system working properly, and I've got probably 18 months of hell left before I > feel like I'll be able to look up and address the multi-disk aspect of btrfs. > RAID0/1/cX modes all work well and are well understood, and that feels "good > enough" to me for right now. I know Johannes is working on something magical, > but IDK what it is or how far out it is. Thanks, > That's fair. I just want to have a better idea of what's in the pipeline here so I can figure out my messaging and roadmap in Fedora. Downstream in Fedora, we have a tracking item for documenting that raid56 should not be used at this time[1], and I just want to collect information for the purpose of providing a more complete picture as part of the documentation. Today, Anaconda will not expose the ability to create raid56 btrfs anyway, so people using that configuration will be relatively rare. But having a good story about it is something I'd like to have, if possible. [1]: https://pagure.io/fedora-btrfs/project/issue/13 -- 真実はいつも一つ！/ Always, there's only one truth! ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: About the state of Btrfs RAID 5/6 2020-09-02 17:37 ` Josef Bacik 2020-09-02 18:18 ` Neal Gompa @ 2020-09-03 7:34 ` Johannes Thumshirn 2020-09-03 8:50 ` Damien Le Moal 2020-09-03 15:02 ` Josef Bacik 1 sibling, 2 replies; 8+ messages in thread From: Johannes Thumshirn @ 2020-09-03 7:34 UTC (permalink / raw) To: Josef Bacik, Neal Gompa, Btrfs BTRFS Cc: David Sterba, Robbie Ko, Zygo Blaxell On 02/09/2020 19:37, Josef Bacik wrote: > I know Johannes is working on something magical, > but IDK what it is or how far out it is. That something is still slide-ware. I hopefully get back to really working on it soonish. So please don't expect patches within the next say 12 months. ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: About the state of Btrfs RAID 5/6 2020-09-03 7:34 ` Johannes Thumshirn @ 2020-09-03 8:50 ` Damien Le Moal 2021-04-20 22:32 ` Neal Gompa 2020-09-03 15:02 ` Josef Bacik 1 sibling, 1 reply; 8+ messages in thread From: Damien Le Moal @ 2020-09-03 8:50 UTC (permalink / raw) To: Johannes Thumshirn, Josef Bacik, Neal Gompa, Btrfs BTRFS Cc: David Sterba, Robbie Ko, Zygo Blaxell On 2020/09/03 16:34, Johannes Thumshirn wrote: > On 02/09/2020 19:37, Josef Bacik wrote: >> I know Johannes is working on something magical, >> but IDK what it is or how far out it is. > > That something is still slide-ware. I hopefully get back > to really working on it soonish. > > So please don't expect patches within the next say 12 months. Come on... You can do better than that :) Joke aside, once we are past the zoned block device support (new version coming this week), we will accelerate that work. -- Damien Le Moal Western Digital Research ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: About the state of Btrfs RAID 5/6 2020-09-03 8:50 ` Damien Le Moal @ 2021-04-20 22:32 ` Neal Gompa 2021-04-20 23:09 ` Damien Le Moal 0 siblings, 1 reply; 8+ messages in thread From: Neal Gompa @ 2021-04-20 22:32 UTC (permalink / raw) To: Damien Le Moal Cc: Johannes Thumshirn, Josef Bacik, Btrfs BTRFS, David Sterba, Robbie Ko, Zygo Blaxell On Thu, Sep 3, 2020 at 4:50 AM Damien Le Moal <Damien.LeMoal@wdc.com> wrote: > > On 2020/09/03 16:34, Johannes Thumshirn wrote: > > On 02/09/2020 19:37, Josef Bacik wrote: > >> I know Johannes is working on something magical, > >> but IDK what it is or how far out it is. > > > > That something is still slide-ware. I hopefully get back > > to really working on it soonish. > > > > So please don't expect patches within the next say 12 months. > > Come on... You can do better than that :) > > Joke aside, once we are past the zoned block device support (new version coming > this week), we will accelerate that work. > Now that we've got ZBD support landing with Linux 5.12 for Btrfs, any chance this might be looked at anytime soon? -- 真実はいつも一つ！/ Always, there's only one truth! ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: About the state of Btrfs RAID 5/6 2021-04-20 22:32 ` Neal Gompa @ 2021-04-20 23:09 ` Damien Le Moal 0 siblings, 0 replies; 8+ messages in thread From: Damien Le Moal @ 2021-04-20 23:09 UTC (permalink / raw) To: Neal Gompa Cc: Johannes Thumshirn, Josef Bacik, Btrfs BTRFS, David Sterba, Robbie Ko, Zygo Blaxell On 2021/04/21 7:33, Neal Gompa wrote: > On Thu, Sep 3, 2020 at 4:50 AM Damien Le Moal <Damien.LeMoal@wdc.com> wrote: >> >> On 2020/09/03 16:34, Johannes Thumshirn wrote: >>> On 02/09/2020 19:37, Josef Bacik wrote: >>>> I know Johannes is working on something magical, >>>> but IDK what it is or how far out it is. >>> >>> That something is still slide-ware. I hopefully get back >>> to really working on it soonish. >>> >>> So please don't expect patches within the next say 12 months. >> >> Come on... You can do better than that :) >> >> Joke aside, once we are past the zoned block device support (new version coming >> this week), we will accelerate that work. >> > > Now that we've got ZBD support landing with Linux 5.12 for Btrfs, any > chance this might be looked at anytime soon? Working on it. But this is not a small change so it will take a while for a patch series to be posted. -- Damien Le Moal Western Digital Research ^ permalink raw reply [flat|nested] 8+ messages in thread
* Re: About the state of Btrfs RAID 5/6 2020-09-03 7:34 ` Johannes Thumshirn 2020-09-03 8:50 ` Damien Le Moal @ 2020-09-03 15:02 ` Josef Bacik 1 sibling, 0 replies; 8+ messages in thread From: Josef Bacik @ 2020-09-03 15:02 UTC (permalink / raw) To: Johannes Thumshirn, Neal Gompa, Btrfs BTRFS Cc: David Sterba, Robbie Ko, Zygo Blaxell On 9/3/20 3:34 AM, Johannes Thumshirn wrote: > On 02/09/2020 19:37, Josef Bacik wrote: >> I know Johannes is working on something magical, >> but IDK what it is or how far out it is. > > That something is still slide-ware. I hopefully get back > to really working on it soonish. > > So please don't expect patches within the next say 12 months. > Have you seen my branch graveyard of things I still need to get back to? Clearly we're not committing to anything here ;). Thanks, Josef ^ permalink raw reply [flat|nested] 8+ messages in thread
end of thread, other threads:[~2021-04-20 23:09 UTC | newest] Thread overview: 8+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2020-09-02 15:10 About the state of Btrfs RAID 5/6 Neal Gompa 2020-09-02 17:37 ` Josef Bacik 2020-09-02 18:18 ` Neal Gompa 2020-09-03 7:34 ` Johannes Thumshirn 2020-09-03 8:50 ` Damien Le Moal 2021-04-20 22:32 ` Neal Gompa 2021-04-20 23:09 ` Damien Le Moal 2020-09-03 15:02 ` Josef Bacik
This is an external index of several public inboxes, see mirroring instructions on how to clone and mirror all data and code used by this external index.