[HN Gopher] ZFS Profiling on Arch Linux
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       ZFS Profiling on Arch Linux
        
       Author : wb14123
       Score  : 142 points
       Date   : 2023-12-15 23:09 UTC (1 days ago)
        
 (HTM) web link (www.binwang.me)
 (TXT) w3m dump (www.binwang.me)
        
       | InvaderFizz wrote:
       | This is a great read. It explains in detail the process of
       | enabling debug symbols and using perf to root cause a performance
       | issue.
       | 
       | I've never done this type of work, but probably will in the
       | future now that I have an example to follow.
        
       | tjoff wrote:
       | It is refreshing to see the author explain how and why all the
       | pieces were gathered. Most guides/instructions/bug-reports only
       | lists the end result, omitting information that helps the reader
       | to get a better understanding and be better equipped to solve
       | related issues.
        
       | sneak wrote:
       | I heard a rumor that ZFS native encryption is somewhat abandoned
       | by its maintainer following it having landed in the release, that
       | it was one person and they moved on/lost interest. I don't know
       | if this is true or not.
       | 
       | I'm still using ZFS on LUKS2 for now, given the issues like this.
       | (You also can't specify multiple keys in ZFS native encryption.)
        
         | xoa wrote:
         | Sadly there have seemed to be a number of rough edges that have
         | stuck around with ZFS native encryption, which is unfortunate
         | given that the cross platform and remote replication advantages
         | are fundamentally very compelling. Honestly it's kind of
         | curious that polishing that experience hasn't been more of a
         | priority, for commercial interests like iXsystems if no one
         | else. Speaking of which, for people running their ZFS off a NAS
         | the idea of just being able to offload all the encryption and
         | FS computation to that is a compelling part of the value
         | equation beyond sheer storage in principle too. Though that in
         | turn (if one does it with iSCSI) runs into another seemingly
         | neglected area of ZFS (zvols). Nothing is perfect.
        
           | zrav wrote:
           | What makes you say zvols are neglected? In fact the people
           | that did most of the work porting ZFS to Linux, i.e. LLNL,
           | use zvols for their HPC cluster and they still employ a
           | number developers and the primary maintainer of ZoL. I also
           | remember a quote from them stating that zvols were in fact
           | more mature than vfs.
        
             | Xorlev wrote:
             | https://github.com/openzfs/zfs/issues/7631
             | 
             | This is a long-standing issue with zvols which affects
             | overall system stability, and has no real solution as of
             | yet.
        
         | justinclift wrote:
         | ZFS on top of LUKS seems to have it's own issues though. :(
         | 
         | https://github.com/openzfs/zfs/issues/15533
        
           | PaulCarrack wrote:
           | Since LUKS is exposed as block device like a hard drive, it's
           | really no different than saying that they are just having
           | issues with certain kind of hard drives.
           | 
           | There is a PR out for this:
           | https://github.com/openzfs/zfs/pull/15588
        
         | zrav wrote:
         | See this discussion about the state of native encryption and
         | the linked list of open bugs:
         | https://discourse.practicalzfs.com/t/is-native-encryption-re...
        
         | wb14123 wrote:
         | More details on this discussion:
         | https://github.com/openzfs/zfs/issues/6824#issuecomment-1817...
         | . Basically he is too busy to continue developing the
         | encryption features but is able to review the related works.
         | 
         | There is also discussion about using ZFS on LUKS in the same
         | thread:
         | https://github.com/openzfs/zfs/issues/6824#issuecomment-1819...
        
       | predmijat wrote:
       | On Arch, zfs-linux package has an exact version of linux as a
       | dependency. linux package gets updated fairly often, and by the
       | time zfs-linux package catches up, linux is already on a newer
       | version and you are unable to upgrade.
       | 
       | Sometimes it takes quite a while before those two are in sync and
       | you can upgrade your system.
        
         | hnlmorg wrote:
         | Is there lts kernel support for zfs-linux? I found I had to
         | switch to the lts kernel on an Arch gaming rig because of
         | issues with Nvidia drivers.
        
           | aperum wrote:
           | There is zfs-linux-lts for that.
        
         | mzi wrote:
         | If you reorder your repositories so the zfs repository comes
         | before the default one in the configuration you won't have that
         | problem.
        
           | commandersaki wrote:
           | Huh, interesting, will have to try that out, thanks.
        
         | tobias2014 wrote:
         | In addition to the other comments: you could use the zfs-dkms
         | package which builds it from source on every update
        
         | 79a6ed87 wrote:
         | Targetting the linux-lts package as a dependency instead of
         | linux should reduce the impact of this issue
        
         | enormousness wrote:
         | You can install the specific older version of the Linux package
         | that the zfs package needs. You can also pin it so it won't get
         | updated by regular upgrades.
        
       | b33j0r wrote:
       | Channelling Erik Dubious: "it's ok, you see the error message,
       | and you navigate to etsy.
       | 
       | This config we find is the answer. I lean into neovim this time,
       | today, because it's all a lessons. And then we type update, and
       | it's all okay!"
       | 
       | The thing he humbly leaves out is "why aren't you an arcolinux
       | fanboy yet!?"
        
         | b33j0r wrote:
         | I am like disturbed that two people thought complimenting
         | Erik's work was worth a downvote. Who the heck hates nice
         | people so much to spend that.
         | 
         | I'm an arch contributor, your're barking up the wrong tree.
        
           | dfc wrote:
           | I think the downvotes had more to do with people not knowing
           | what/who you are referring to. Without the context that you
           | have your comment seems like word salad.
        
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       (page generated 2023-12-17 23:00 UTC)