c0t0d0s0.org

c0t0d0s0.org · Personal blog · on HN since 2008

A Sun Microsystems engineer's sysadmin blog on Solaris features, ZFS, virtualisation and storage design.

What HN saysHN links it for Solaris explanations such as privileges and encrypted networking, and for a Sun engineer's critical perspective on Backblaze's DIY storage pods.
19HN people shared it
13linked it in comments
18stories submitted
344story points
9 years agolast shared
2008people per year2026

Most-shared posts

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    The impact of virtualisation
    2 people · 1 points · first shared 2009 · discussion on HN
  4. 4
    No, ZFS really doesn't need an fsck tool
    1 people · 112 points · first shared 2013 · 58 comments on HN
  5. 5
    Thoughts of a sysadmin starting to get old ...
    1 people · 18 points · first shared 2009 · 24 comments on HN
  6. 6
    Sun isn't just that small RDBMS...
    1 people · 8 points · first shared 2009 · discussion on HN
  7. 7
    C0t0d0s0 goes down
    1 people · 7 points · first shared 2011 · 4 comments on HN
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    Is the Linux community afraid of Opensolaris?
    1 people · 5 points · first shared 2008 · 2 comments on HN
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    Oracle/Sun: Ideas are mergerproof
    1 people · 2 points · first shared 2010 · discussion on HN
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    1.9 TB & 1.6 Million IOPS in 1 RU
    1 people · 1 points · first shared 2009 · discussion on HN

What HN people wrote when they linked it

bcantrill · 2013-02-20
I think it's worth (re)reading this comment on the original Storage Pod from several years ago: http://www.c0t0d0s0.org/archives/5899-Some-perspective-to-this-DIY-sto… I have essentially have all of the same questions for Storage Pod 3.0 -- and in particular, what does the software stack look like? (This config is absolutely begging for ZFS, but I have a haunting feeling that something janky is afoot upstack.) I would also be curious as to the specific nature of failures that have been seen with the deployed architecture. Have the concerns from three years ago proven to be alarmist or prescient? That said: I think it's very valuable to get configs like this out there for public discussion -- and I think it might be inspiring us (Joyent) to similarly publicly discuss our own high density storage config...
eckyptang · 2012-09-04
I genuinely can't think of anything else I'd rather use less than this. I think MAC (Mandatory Access Control) applied to a desktop environment, picking a better language than C and actually thinking about stuff is more than sufficient to get around the existing problems... Virtualization is just another pile of complexity and performance problems to deal with. It's not a magic bullet. Consider the following as well: http://www.c0t0d0s0.org/archives/3651-Theo-de-Raadt-about-virtualisati… I really don't want this solution.
binarycrusader · 2015-11-11
1. "interesting definitions"... Understood. 2. code size: I see that conceptually these 2 code samples work similarly, but one has 5x more LOC. I think that's nit-picking a bit, especially since, as I said, there are some other convenience functions that could be used depending on the situation. But regardless, it's hardly onerous. We're talking about 7 lines of actual code vs. 2 lines. That's not even worth arguing about, especially as most applications do this once if they're permanently dropping privileges. 3. dropping and picking up isn't really dropping: If I drop privileges, but can pick them back up, then if I decide to misbehave, picking them back up is just something I do first. Dropping them with the possibility of picking them up is security theater, not actual security. No, it's actually not security theatre at all. I think you misunderstand the threat model that's trying to be addressed. The kernel is enforcing the restrictions. Note that I also specifically said Solaris allows both -- the developer can temporarily drop privileges or can permanently drop them or use a combination thereof. Each style of interface is appropriate for a different situation. For example, consider a case where your program allows the execution of a user script to retrieve a password required to unlock an SSL Private Key file (Apache does this). For the duration of that operation, you can set your effective privileges to be very limited, and thus any programs you…
gonzo · 2015-07-19
Canaries and other techniques that leverage volatiles do not prevent an overflow; they just try to cope with the consequences of an overflow which has happened. (This is why they're generally lumped together as "mitigation".) The canary tries to detect the case of an overflow which overwrites the return address in a stack frame. Data Execution Prevention (DEP) takes this idea a step further, it assumes that the return address has been overwritten and followed, and it restricts the areas where execution could jump. ASLR is yet another step further: it "shuffles" the areas where execution is allowed. More specifically, stack canaries work by modifying every function's prologue and epilogue regions to place and check a value on the stack respectively. As such, if a stack buffer is overwritten during a memory copy operation, the error is noticed before execution returns from the copy function. When this happens, an exception is raised, which is passed back up the exception handler hierarchy until it finally hits the OS's default exception handler. If you can overwrite an existing exception handler structure in the stack, you can make it point to your own code. This is a Structured Exception Handling (SEH) exploit, and it allows you to completely bypass the canary check. DEP and NX (what OpenBSD calls W^X) mark important structures in memory as non-executable, and force hardware-level exceptions if you try to execute those memory regions. This makes normal stack buffer…
Mister_Snuggles · 2017-09-06
This[0] seems to answer your questions. TL;DR: The kernel does it all and passes the unencrypted traffic to the local port specified. There's a command to configure it with the appropriate keys, etc. [0] http://www.c0t0d0s0.org/archives/5575-Less-known-Solaris-Features-kssl…
glabifrons · 2013-03-29
"How? ZFS refuses to mount/import a corrupt filesystem." zpool clear -F $POOLNAME http://www.c0t0d0s0.org/archives/6067-PSARC-2009479-zpool-recovery-sup…
X-Istence · 2012-12-05
If you are on Solaris (10 or higher works from experience) you can grant a single user the ability to bind to the lower ports: usermod -K defaultpriv=basic,net_privaddr ${user} You can off course also assign the privileges to a role, and then assign the user that role so as required they can su to the role and use the privileges. Here is a pretty neat description of what is possible and why it is pretty awesome: http://www.c0t0d0s0.org/archives/4075-Less-known-Solaris-features-RBAC… --- On FreeBSD if you have the MAC framework enabled, you can use the portacl module to give new privileges: sysctl security.mac.portacl.rules=uid:$user_id:tcp:80 See http://www.freebsd.org/doc/en_US.ISO8859-1/books/handbook/mac-portacl.… for more information.
piotrSikora · 2012-08-08
> What a non-article. ZFS is more mature than an unmature and unstable filesystem? Really? Keep in mind that, with one exception, ZFS is pretty much rock-solid from day one. Also, you should really read: http://www.c0t0d0s0.org/archives/6071- No,-ZFS-really-doesnt-need-a-fsck.html
sciurus · 2011-04-25
Neat project! However, I would consider changing the name. There's already a CacheFS in Solaris. http://www.c0t0d0s0.org/archives/4727-Less-known-Solaris-Features-Cach… Linux has a similar feature named FS-Cache, and one of its storage backends is named CacheFS. http://people.redhat.com/~dhowells/fscache/FS-Cache.pdf Do you really want to make this situation even more confusing?
zdw · 2010-10-12
Basically, it's a more-current version of the Linux kernel added to their distro (which is a clone of RHEL5). Surprise surprise... the newer kernel has more performance optimizations and is somewhat faster/featureful. There are a few new features - see here for more on one of the data integrity ones: http://www.c0t0d0s0.org/archives/6919-About-this-data-integrity-thing-…
bensummers · 2010-03-04
Here's a good SMF resource, by the ever reliable c0t0d0s0! http://www.c0t0d0s0.org/archives/4144-Solaris-Features-Service-Managem…
fhars · 2009-08-21
You'd actualy put the disks into a Sun X4500 which you can just put into a rack at the destination site: http://www.c0t0d0s0.org/archives/4260-Less-known-Solaris-Features-Remo…

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