Docker 0.8: Quality, new builder features, btrfs, OSX support • Hacker News Board

Re: Docker 0.8: Quality, new builder features, btrfs, OSX support

#121

Post by garthk » Fri, Feb 07, 2014, 9:43 PM UTC

midas007 wrote: post #48

It's confusing why btrfs support was prioritized ahead of zfs considering zfs' superior architecture and ops capabilities. Is docker (formerly dotcloud) going to start withholding capabilities as licensed features? Edit: prelim zfs driver work is here https://github.com/gurjeet/docker/tree/zfs_driver

Docker doesn't prevent use of ZFS.

It's common and easy to mount your host FS into the container, putting mutating data where you can take full advantage of the superior architecture and ops capabilities of whichever FS you prefer.

The images' internal AUFS/BTRFS layers are then only for keeping your binaries-at-rest and static configuration straight. They may as well be in highly indexed ZIP files, for all you care.

Re: Docker 0.8: Quality, new builder features, btrfs, OSX support

#122

Post by atoponce » Fri, Feb 07, 2014, 9:44 PM UTC

tacticus wrote: post #49

midas007 wrote: post #48

It's confusing why btrfs support was prioritized ahead of zfs considering zfs' superior architecture and ops capabilities. Is docker (formerly dotcloud) going to start withholding capabilities as licensed features? Edit: prelim zfs driver work is here https://github.com/gurjeet/docker/tree/zfs_driver

What superior architecture does zfs have?

* ZFS is a volume manager.

* ZFS is a RAID manager.

* ZFS is also a filesystem.

* Writes are handled in transaction groups (TXGs).

* Every transaction group is written atomically.

* ZFS keeps a revision history of the past 128 transactions written to disk.

* ZFS is a Copy on Write filesystem.

* As such, due to the previous 2 features, snapshots are free.

* Snapshots are first class, read-only filesystems.

* Snapshots can be upgraded to read-write clones.

* Snapshots can be sent and received to other locations.

* ZFS uses block-level deduplication.

* ZFS supports transparent compression.

* Every metadata and block data is checksummed with SHA256 by default.

* Other checksum algorithms are supported.

* ZFS uses a "slab allocator" to minimize fragmentation.

* ZFS implements an "intent log" for synchronous writes.

* The intent log can be migrated to a fast SSD or NVRAM drive.

* ZFS uses advanced caching implementing for MRU/LRU and MFU/LFU caches.

* A secondary cache (outside of RAM) can be installed on fast SSDs.

* ZFS uses dynamic striping with its RAID arrays.

* ZFS supports triple parity RAID.

* ZFS autoheals bit rot when a block does not match its checksum, if the pool is redundant.

* ZFS fully supports advanced format disks (4k blocks and beyond).

* In fact, block sizes are dynamic from 512 bytes to 128K (or 1M in the proprietary ZFS).

* In the proprietary release of ZFS, native encryption is supported.

* In the Free Software release of ZFS, "feature flags" have been introduced to add on "plugins" without changing the core of the filesystem.

* ZFS supports native NFS, allowing the mount to be available before the export.

* ZFS supports native SMB for the same reason.

* ZFS supports native iSCSI, also for the same reason.

* ZFS can create static sized block devices called "ZVOLS".

* ZFS pools can be exported and imported.

* ZFS "scrubs" data to find blocks that do not match their checksum.

* The Free Software release of ZFS is supported on GNU/Linux, OpenIndiana, SmartOS, FreeBSD, and many other operating systems.

* Administration of ZFS is done via 3 commands: zpool(8), zfs(8) and zdb(8).

Re: Docker 0.8: Quality, new builder features, btrfs, OSX support

#123

Post by zobzu » Sun, Feb 09, 2014, 7:29 AM UTC

nickstinemates wrote: post #54

zobzu wrote: post #34

Earlier quoted context omitted.

its not as good as using separate vms, but has arguably lower overhead also, its not really docker doing that, its LXC. Docker is an API around it.

Docker is not an API around LXC. Any more than any application using a framework is a wrapper around said framework. However, the analogy I just made is only at a point in time. LXC is not the only Linux provider to manage cgroups/namespaces, it was just the most convenient at the time for the target audience. That is a fleeting position soon remedied. If you'd like to know more, I'd encourage you to get involved wit…

yeah, docket is an api around namespaces.. and thus lxc, right now.

thanks for nothing really.

Re: Docker 0.8: Quality, new builder features, btrfs, OSX support

#124

Post by wslh » Tue, Feb 11, 2014, 10:09 PM UTC

newman314 wrote: post #79

IMO, it would be fantastic if there was something like Docker for Windows. Imagine being able to bundle up games in individual containers and easily being able to move them from machine to machine as you upgrade. Same thing applies for other Windows apps.

Docker is to Unix almost as Microsoft App-V/VMware ThinApp/Symantec Workspace Virtualization products are to Windows.

Not exactly the same but closer.

Re: Docker 0.8: Quality, new builder features, btrfs, OSX support

#125

Post by newman314 » Wed, Feb 12, 2014, 6:00 AM UTC

wslh wrote: post #124

newman314 wrote: post #79

IMO, it would be fantastic if there was something like Docker for Windows. Imagine being able to bundle up games in individual containers and easily being able to move them from machine to machine as you upgrade. Same thing applies for other Windows apps.

Docker is to Unix almost as Microsoft App-V/VMware ThinApp/Symantec Workspace Virtualization products are to Windows. Not exactly the same but closer.

Precisely, it's not the same. There still a whole bunch of fiddling going on.

I'll stick to my statement. I want something Docker-like for Windows so that I can easily move things from one machine to another.

Re: Docker 0.8: Quality, new builder features, btrfs, OSX support

#126

Post by darkarmani » Wed, Feb 12, 2014, 3:43 PM UTC

72deluxe wrote: post #106

pekk wrote: post #41

Earlier quoted context omitted.

and I'm always told that macs are superior because they "just work," hmm

That's marketing. They have the same number of problems as all other OSes and computers. I have found a higher percentage of Windows users to know where to look for system messages compared to the number of Mac users who know how to look for system messages. Perhaps it is because I have met more Windows users or perhaps they need to look these things up more...? But in any case, you meet more "hardcore" Windows users…

> That's marketing. They have the same number of problems as all other OSes and computers.

Absolutely not! I have to support my parents using a computer and I bought them a mac mini 6-7 years ago, because they would always get their windows machine in an unusable state where i couldn't even remotely connect to help. Using a mac, they can do the things they need to do with almost no problems: store photos, backup, email, web browse, facetime, ichat. That would be impossibly for them on a windows machine.

Re: Docker 0.8: Quality, new builder features, btrfs, OSX support

#127

Post by wslh » Tue, Feb 18, 2014, 2:45 AM UTC

newman314 wrote: post #125

wslh wrote: post #124

Earlier quoted context omitted.

Docker is to Unix almost as Microsoft App-V/VMware ThinApp/Symantec Workspace Virtualization products are to Windows. Not exactly the same but closer.

Precisely, it's not the same. There still a whole bunch of fiddling going on. I'll stick to my statement. I want something Docker-like for Windows so that I can easily move things from one machine to another.

It seems like they are working on it: "Microsoft Corporation : Patent Issued for Extensible Application Virtualization Subsystems" http://www.4-traders.com/MICROSOFT-CORPORATION-4835/news/Mic...

Re: Docker 0.8: Quality, new builder features, btrfs, OSX support

#128

Post by midas007 » Wed, Feb 19, 2014, 10:03 PM UTC

atoponce wrote: post #122

tacticus wrote: post #49

Earlier quoted context omitted.

What superior architecture does zfs have?

* ZFS is a volume manager. * ZFS is a RAID manager. * ZFS is also a filesystem. * Writes are handled in transaction groups (TXGs). * Every transaction group is written atomically. * ZFS keeps a revision history of the past 128 transactions written to disk. * ZFS is a Copy on Write filesystem. * As such, due to the previous 2 features, snapshots are free. * Snapshots are first class, read-only filesystems. * Snapshots…

Great list.

L2ARC, zil can each have their own volume configuration (mirror, etc.) For example, using different types of SSDs for each. http://forums.freenas.org/index.php?threads/zfs-and-ssd-cach...

zfs send & receive ... Send snapshots around like a fancy SAN.

raidz (N+1 - like raid5) raidz2 (N+2 - like raid6) raidz3 (N+3)

It's also way faster and cheaper to put together boxes from commodity enterprise server hardware, making hardware raid cards basically expensive shelf dust catchers along with overpriced SANs and NASes.

(Extra shout out for iXsystems, not because they use lots of Python, but because of massive awesomeness supporting FreeBSD and FreeNAS. Also their parties put Defcon afterparties to shame.)

Conclusion: Full ZFS is often better than a SAN, NAS and/or hardware solutions. Also protip: Direct attached is way, way faster than 10 GbE, FC or IB, especially if images are directly available to compute nodes.