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This is not a swipe at Docker; it's an interesting technology if you're running Linux and I'm sure it will be very valuable to many. However, let's not forget

This is not a swipe at Docker; it's an interesting technology if you're running Linux and I'm sure it will be very valuable to many. However, let's not forget that Solaris had this functionality first. Solaris has offered hypervisor-level virtualization (LDOMS) on SPARC, light-weight "virtualization" (Containers/Zones) on SPARC/x86, and now offers full system virtualization out of the box (Kernel Zones) SPARC/x86. And there's also OpenStack and Puppet system management integration in Solaris 11.2+.

evol262 12y ago
Not really. Even in an absolute sense, linux-vserver is/was contemporary with zones. Yes, in the sense that partitioning technology isn't new. zones and jails are comparable to vserver/openvz/lxc. vpars, lpars, and ldoms have analogues on mainframes. Various hypervisor technologies (xen, kvm, vmkernel) are also not unique to solaris, and were done on Linux. What Docker offers that none of these do not is that it's containerization for applications without the "weight" of even zones. It's not virtualizing systems. It's starting one application in its own container. That's it. I don't know who's spreading this "Docker is just like zones" FUD, but it's wrong. Linux has had container-level virtualization for a decade, and LXC has had mainline support for a while. Docker builds on that, but it's different. At the same time, EMC is not shitting themselves over docker. Application containers will not replace traditional or container virtualization for all workloads. But they will for some.
- benjarrell 12y ago
  Having never used Docker, if it is containerization for applications, how is it different from Application WPARs or App-V?
  - evol262 12y ago
    It's analogous to App-V or an Application LPAR, if such a thing existed, but these are both good examples. My complaint to the previous poster is mostly that it differs in the same way that an Application WPAR differs from a WPAR. Yes, they're the same base. No, they're not the same thing.
- binarycrusader 12y ago
  Sorry, but I'm going to disagree. linux-vserver is not contemporary with zones. If you think that it is, you haven't looked at Solaris zones technology very carefully. linux-vserver requires the kernel to be patched; Solaris zones does not. linux-vserver has no clustering or process migration capability; Solaris zones in combination with LDOMs gives you a path for live migration. linux-vserver networking is based on isolation, not virtualization. This means each virtual server can't create its own internal routing or firewall setup -- Solaris zones can. linux-vserver doesn't fully virtualize the system; clock, parts of /proc and /sys are not virtualized. So no, linux-vservers are not equivalents. Yes, docker offers containerization -- but not sufficient containerization. Certainly not sufficient for security purposes as have come up repeatedly in recent history. As for the "weight" of zones; I don't know what "weight" you're talking about. Solaris zones have almost no overhead at all. They use some disk space, but we're talking less than 300MB if I recall correctly at most in a default configuration. And Solaris Zones give you several advantages that Docker doesn't provide. Regardless, I'm certain that for some specific use cases, Docker will prove an appropriate technology.
  - pstuart 12y ago
    All good, except that Solaris is a ghetto.
    - binarycrusader 12y ago
      All good, except you didn't bother posting anything of meaningful value. In what way, precisely, can Solaris objectively be qualified as what you describe?
      - pstuart 12y ago
        Meaning that while Solaris had many technical advantages over Linux, it's not exactly a vibrant and growing community. Do you really think that any greenfield endeavor is going to pick Solaris as its OS? Disclaimer: I just left a gig where I spent 6 years in a Solaris shop, and while there wrote an on-demand zones management system.
- rdtsc 12y ago
  > Docker builds on that, but it's different. So what is different? You wrote whole paragraph about what it isn't. But what is it then that make Docker not just LXC (other container) + scripts to manage applications in it. One could presumable still spawn a single application on any OS...
  - evol262 12y ago
    Docker is application containerization. While Docker is built on top of libcontainer and cgroups (used to be LXC), traditional containers, including LXC and zones, start init and enough services to look like a "normal" system. You can still use rc.local to manage applications if you want to, I guess. Docker is a build system for containers which run /bin/foo as PID1, with no services, no ssh, and no init (which presents other problems reaping children, handling sigterm, etc). It's containerization for application virtualization.

evol262 12y ago

Not really. Even in an absolute sense, linux-vserver is/was contemporary with zones. Yes, in the sense that partitioning technology isn't new. zones and jails are comparable to vserver/openvz/lxc. vpars, lpars, and ldoms have analogues on mainframes. Various hypervisor technologies (xen, kvm, vmkernel) are also not unique to solaris, and were done on Linux. What Docker offers that none of these do not is that it's containerization for applications without the "weight" of even zones. It's not virtualizing systems. It's starting one application in its own container. That's it. I don't know who's spreading this "Docker is just like zones" FUD, but it's wrong. Linux has had container-level virtualization for a decade, and LXC has had mainline support for a while. Docker builds on that, but it's different. At the same time, EMC is not shitting themselves over docker. Application containers will not replace traditional or container virtualization for all workloads. But they will for some.

benjarrell 12y ago
Having never used Docker, if it is containerization for applications, how is it different from Application WPARs or App-V?
- evol262 12y ago
  It's analogous to App-V or an Application LPAR, if such a thing existed, but these are both good examples. My complaint to the previous poster is mostly that it differs in the same way that an Application WPAR differs from a WPAR. Yes, they're the same base. No, they're not the same thing.
binarycrusader 12y ago
Sorry, but I'm going to disagree. linux-vserver is not contemporary with zones. If you think that it is, you haven't looked at Solaris zones technology very carefully. linux-vserver requires the kernel to be patched; Solaris zones does not. linux-vserver has no clustering or process migration capability; Solaris zones in combination with LDOMs gives you a path for live migration. linux-vserver networking is based on isolation, not virtualization. This means each virtual server can't create its own internal routing or firewall setup -- Solaris zones can. linux-vserver doesn't fully virtualize the system; clock, parts of /proc and /sys are not virtualized. So no, linux-vservers are not equivalents. Yes, docker offers containerization -- but not sufficient containerization. Certainly not sufficient for security purposes as have come up repeatedly in recent history. As for the "weight" of zones; I don't know what "weight" you're talking about. Solaris zones have almost no overhead at all. They use some disk space, but we're talking less than 300MB if I recall correctly at most in a default configuration. And Solaris Zones give you several advantages that Docker doesn't provide. Regardless, I'm certain that for some specific use cases, Docker will prove an appropriate technology.
- pstuart 12y ago
  All good, except that Solaris is a ghetto.
  - binarycrusader 12y ago
    All good, except you didn't bother posting anything of meaningful value. In what way, precisely, can Solaris objectively be qualified as what you describe?
    - pstuart 12y ago
      Meaning that while Solaris had many technical advantages over Linux, it's not exactly a vibrant and growing community. Do you really think that any greenfield endeavor is going to pick Solaris as its OS? Disclaimer: I just left a gig where I spent 6 years in a Solaris shop, and while there wrote an on-demand zones management system.
rdtsc 12y ago
> Docker builds on that, but it's different. So what is different? You wrote whole paragraph about what it isn't. But what is it then that make Docker not just LXC (other container) + scripts to manage applications in it. One could presumable still spawn a single application on any OS...
- evol262 12y ago
  Docker is application containerization. While Docker is built on top of libcontainer and cgroups (used to be LXC), traditional containers, including LXC and zones, start init and enough services to look like a "normal" system. You can still use rc.local to manage applications if you want to, I guess. Docker is a build system for containers which run /bin/foo as PID1, with no services, no ssh, and no init (which presents other problems reaping children, handling sigterm, etc). It's containerization for application virtualization.