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bio website kbrandt.com
location Hollywood, FL
age 32
visits member for 5 years, 7 months
seen 7 hours ago

I'm the director of site reliability at Stack Exchange. I'm also the co-author of the bosun monitoring system and sometimes blogger on the Server Fault Blog.

@KyleMBrandt


Jun
18
comment How does vm.overcommit_memory work?
@MikhailMorfikov: In theory, I believe so, but who knows what these programs are doing. Would want to see a more controlled environment with a simple program that just allocates say a gig of ram via Malloc. And then run the test after rebooting between tests.
Jun
16
comment What is the maximum theoretical throughput of a NAS device to 100 workstations with 1Gb/sec connections?
Ya, just keep what TomTom said in mind, VDI is likely highballing it. But when you lack information, and you have the budget, better too much than too less.
Jun
16
comment iDRAC login loop
Also, if there are too many log in attempts with a false password, iDRACs will block people from logging without telling them for what seems to be an undocumented amount of time....
Jun
16
comment What is the maximum theoretical throughput of a NAS device to 100 workstations with 1Gb/sec connections?
You could also assume their entire workstation is hosted on the SAN, and pretend you are building a Virtual Desktop Infrastructure (VDI) and use some estimators like blogs.citrix.com/2010/10/31/… .
Jun
15
comment Why is Router IP Address Repeated in Trace Command?
@FelixFrank: In addition to the routing table, capture captures with a tool like tcp might provide insight. In particular observe the IP header.
Jun
13
comment Agentless monitoring: how does it work? Advantages over traditional monitoring?
@syneticon-dj: Eventually :-P
Jun
11
comment Find out ESXi host from VM?
@mfinni: Because we have monitoring agents on every Windows / Linux host pushing to the monitoring system, and currently don't have anything using the vSphere API as of yet. So this is likely more convient as thing currently stand.
Jun
11
comment Find out ESXi host from VM?
This is for monitoring. I'd like to tag every VM with its Current VM Host. So I want an option where this is updated at runtime and not hardcoded into the VMs config. It doesn't have to be instance, could be something refreshed every X minutes
Jun
7
comment Choosing the right AWG for Server Power Cables?
I don't like them myself, but I'm usually not the one working in the datacenters, so I leave it up those guys.
Jun
7
comment Choosing the right AWG for Server Power Cables?
We used 14s, combined with cable arms, that is a bad choice. They end up popping out of the servers even when you velcro them in nice and tight. We are redoing everything with 16 now (Which is thinner). So this is something to keep in mind.
Mar
18
comment Entropy Deprivation on Bind / Named Servers
@vonbrand: Ah thanks for the emphasis, I'll look into that
Mar
18
comment Entropy Deprivation on Bind / Named Servers
@vonbrand: Don't see a correlation between entropy and packets per second. Would like to understand the cause more before getting into way to generate more entropy.
Mar
18
comment Entropy Deprivation on Bind / Named Servers
@ShaneMadden: Just authoritative
Sep
19
comment Disk Capacity Planning for Whisper / Graphite
Okay, so with this retention settings. Roughly: ServerCount * MetricCount * 4.5MBytes
Sep
19
comment Disk Capacity Planning for Whisper / Graphite
Thanks for this. So with the filesize, is that what it will be after an hour of collecting data, or is that what the filesize will pretty much always be? So is 4415092 representative of 5 years worth of data this retention, or is that representative of one hour of 1 minute data? Also, is that bytes or bits?
Sep
19
comment Disk Capacity Planning for Whisper / Graphite
Any chance you have some sample numbers from that (paired with retention settings). Right now I'm thinking about different time series data stores in terms of disk usage - so getting graphite live for that is bit a of a todo.
Sep
17
comment Disk Capacity Planning for Whisper / Graphite
Ya, that math is straightforward, I'm really just looking more on how Graphite stores it data - can make major differences at scale. The only thing I have found is that according to the docs it is not very space efficient (Probably because it counts on fairly aggressive rollups).
Aug
1
comment How to edit TCP window size from iptables?
Have to admit, pretty curious as to why you would want to do this?
Mar
5
comment When using TCP load balancing with HAProxy, does all outbound traffic flow through the LB?
@TimvanElsloo: The network stack will the load balancers IPs, if you add option forwardfor HAProxy will add an HTTP header, X-Forwarded-For IIRC, with the original IP.
Feb
14
comment IOAT enabled but not being used with Linux?
@mdpc: CentOS 6.3, tried a much newer kernel to see if it would help, but it didn't. This was a secondary issue discovered when having high si% on ksoftirqd with ipsec traffic (not that I expect offloading on the ipsec traffic itself, but would seems there is no ioatdma at all.