chris

6,359 reputation

11329

bio	website
	location	Boston, MA
	age
visits	member for	3 years, 11 months
	seen	May 15 at 15:10
stats	profile views	661

	6,359 reputation	bio	website		visits	member for	3 years, 11 months
11329 badges		location	Boston, MA		seen	May 15 at 15:10

summary answers questions tags badges favorites bounties reputation activity

461 Comments

suggestions reviews revisions comments badges posts accepts all

May 10	comment	Better/alternate front-end/graphs for munin? @sciurus: First let me say that as of right now, I haven't actually finished this so I may change it around completely... But my feeling is that if I've got both the RRD and a raw CSV available, I'll have more options for a graphing back-end than if I only had one. And I suspect I'd have an easier importing / feeding a CSV into whisper than an RRD, or at worst, they'd be equally hard / easy.
May 10	comment	Better/alternate front-end/graphs for munin? I recently did "read up on status / monitoring / trending" compare and contrast and decided to use collectd for the majority of our systems monitoring. You can output CSV files and rrd at the same time; my plan is to export the CSV into something like graphite after I've got all the rest of everything worked out.
May 9	comment	mirrored filesystem across a few servers The key to understanding OpenAFS is that it is a cache management system -- there is one namespace (IE only one "file" exists) but there are cached copies of the file everywhere and a protocol to make sure that all the cached copies are consistent. If you lose the master you can turn one of the cached copies into the master, but it isn't ideal to be in that situation.
May 9	comment	mirrored filesystem across a few servers Yep. And it is possible, though annoying, to recover from losing the primary master. But it is trivial to have multiple writers and the resulting blocks stored on multiple hosts.
May 8	comment	Domain reg - own server - need nameserver I'm a control freak. I don't do anything important on that box. I did/do it to learn exactly how things work. I would never suggest you do this for anything even slightly important, but it is valuable / useful to know how the whole stack works. Oh -- and the VPS service I have is extremely inexpensive.
Apr 27	comment	Setting nagios location in map @mech: The whole point of the parent mechanism is to allow nagios to tell the difference between a host being down and a host being un-reachable because the network between nagios and the monitored system is down. So in a nagios world, ideally, you put the gatways on nagios and make those the parents of the other things.
Apr 20	comment	What are useful .screenrc settings? @murail I prefer using the scrolly wheel thingy in my mouse when I'm using putty; just habit. @mikeage -- I found that if you get rid of the seconds on the clock it makes the scrollback buffer on screen work pretty well. Of course, I mostly have a clock on my screen to avoid the stupid idle timeouts we've got on our damned firewalls. grrr.
Mar 1	comment	Skype and internal networks using rfc1918 space @evan right -- I'm worried about hairpin traffic going over a laggy (for the BO) link instead of directly from 10.0.0.0/8 to 10.0.0.0/8.
Feb 27	comment	Network Sniffing and Hubs It looks like there are some old netgear products sold in the amazon marketplace, but their "marketplace" is pretty similar to ebay. Netgear doesn't appear to be making these things any longer. And geez, $80? For a hub? Really? I'd think cgi.ebay.com/290430680833 is a far better deal...
Feb 27	comment	Network Sniffing and Hubs These days the only reliable place to get a hub is your basement. Otherwise, look on ebay, but once there you may as well look for old nortel switches or similar less desired but still really nice networking equipment. Old nortel switches, for instance, can mirror to a port based on things like the source or target MAC address as well as source port or vlan.
Feb 27	comment	Network Sniffing and Hubs @eater - that was certainly the case long ago when these things came out, but I'm not sure it's still the case. I'd expect that the chipsets to make 10/100 hubs are probably no cheaper than a switch-on-a-chip chipsets, and maybe more expensive because they aren't made in volume anymore. Certainly any old-stock is exempt from this, but stuff on newegg? I'm not sure you'd win that bet often enough to want to play the game.
Feb 25	comment	How do I clear the “s” permission on a directory in Linux? In unix, the inode is the thing that gets the permissions.
Feb 24	comment	ZFS Like Alternatives on Windows Snapshots, volume sizing, and cloning aren't functions of a SAN, per se. They may be features of a specific implementation of a SAN, but in general with a SAN you just get a reliable way of storing blocks on a random access device. And, it is far easier to implement this functionality using a NAS than a SAN because the NAS operates at a filesystem layer instead of a block-level storage layer.
Feb 24	comment	Why are datacenters built over a wide area instead of using taller buildings? Right -- one summer is actually the smallest of these facilities. The 111 eighth ave facility is a city block that was originally a warehouse / repair facility for New York city's MTA. Not a small building, but not a purpose-built datacenter.
Feb 24	comment	Why are datacenters built over a wide area instead of using taller buildings? In cities typically old cement warehouses are retrofitted to be datacenters. This is especially true of "cold storage" facilities that were originally designed to keep stuff cold. Nice hefty cement floors that can support huge weights, no windows, fireproof construction, and heck, they're already there so no permits to pull or neighbors to annoy with construction.
Feb 24	comment	Why are datacenters built over a wide area instead of using taller buildings? Warehouses in cities tend to be multi-story affairs. Lots of 10 story cement buildings around where I live, typically painted white with "cold storage" written in block letters on the side...
Feb 22	comment	How can I set up VLANs in a way that won't put me at risk for VLAN hopping? The basic problem is that there are also VMs in the mix and he must trust that the VMs are as trustworthy as the switches.
Feb 22	comment	What else do I get with Cat 6 beyond future proofing my wiring? If it isn't cat6a you've got no promises from anyone. This includes cat6 or cat5e or even cat5. A single run is far more likely to work properly than 50 cables in a conduit all running 10gigE because of alien crosstalk issues. But in practice, cat5e usually works. The question here, of cat5e vs cat6, though, is simple -- no value in 6 vs 5e at all. Zero. Zip. Nada. Zilch. Just more money for the cable guys.
Feb 22	comment	What else do I get with Cat 6 beyond future proofing my wiring? None of those features actually make anything work faster. Just like plumbing -- if your pipes are plastic or copper or gold, or steel, they all flow the same volume of water for the same inner diameter pipe. Sure, some of them have higher melting points or corrode faster, but that's not relevant to the question at hand.
Feb 22	comment	What else do I get with Cat 6 beyond future proofing my wiring? But I was lucky. Some of the luck was that I was careful in crimping the ends (a cable tester actually said the cable tested as cat6) and I was lucky that the alien crosstalk around the cable wasn't enough to cause errors.