1,367 reputation
179
bio website redhardsupra.blogspot.com
location Laurel, MD
age 37
visits member for 5 years, 2 months
seen 2 days ago

Aug
15
answered Creating tmpfs file system in xen server to store VM
Aug
2
comment Improving TCP performance over a network with small packet loss
I've had good results with hybla, give that a try.
Jul
19
comment How do I parse a log file for one hour with a simple shell script?
Rotate your logs hourly, run analysis on the individual log, which happen to be hour long.
Jun
25
comment Resize base XenServer 6.0 partition
I figured it wasn't that important, since you're screwing with partitions on it ;) in that case, if you have enough space you can yum install gcc and compile gdisk or parted in Dom0.
Jun
25
answered Resize base XenServer 6.0 partition
May
27
awarded  Yearling
Mar
23
comment Grepping through the results of apachectl -S
What you pipe to grep is stdout, are you sure that apachectl -S is dumping to stdout, or stderr? Redirect stderr to stdout, grep on that.
Mar
9
comment Anything Close to an NSA Guide for Securing RHEL 6
I don't think RHEL6 have been approved for anything gov/mil operations yet, so no STIGs or SNACs have been released.
Mar
8
comment Faster MySQL DB pull from remote machine into local machine
Good point on using ssh's internal ability to gzip. However, in the modern times, it's advisable to use things like pbzip2, as it can take advantage of (sometimes significant) number of cores. The traditional bzip2 is rather slow, but pbzip2 on a modern box will amaze you.
Mar
6
comment monitor IO to tmpfs partition?
Running PV adds its own bottlenecks, usually invisible at disk speeds, but they will be significant at RAM speeds. Beware.
Feb
15
comment limit linux background flush (dirty pages)
What's your methodology to arrive at the '15MB for dirty_buffers is optimal' part?
Feb
13
answered Intel igb driver packet loss on Debian Linux 6.0
Feb
13
answered To improve SQL performance, why not just put lots of RAM rather than having faster hard disks?
Jan
20
comment 2.5 inch drives versus 3.5 inch drives
I could see the contrary: longer tracks contain more data, thus as long as the file system places clusters similar data, the need for seeking altogether might be lower, even though the duration of the seek itself might be longer. From some benchmarks I've seen, seeking just one track takes miliseconds, and it's not that much smaller than seeking a full inside-to-out distance. So I'd rather have denser media, or longer tracks (or whatever allows me to do a sequential read without seeking), than lots of 'fast' seeks. I guess what I'm trying to say is there is no better seek than no seek at all.
Jan
10
awarded  Popular Question
Dec
9
comment Setting MTU Per Destination Host
Dunno about OSX, but in normal *nixes, MTU tends to be set per interface, not per host. Maybe you could create a bunch of virtual interfaces with individual MTU's, and give them IP's on different networks, so routing would take care of picking the right interface, and the different MTU in the process? Just an idea... don't shoot me.
Dec
6
comment tuning linux cache settings for inode caching
Yup, I run updatedb from cron to keep the inode cache 'warm.' It works well, take a look at your slabtop to see statistics. Also, running strace -c updated can give you some insight as far as how much gets updated.
Dec
5
comment Encryption between a LAN switch and an end device
IPSec is a higher layler protocol, do you specifically want Link Layer encryption?
Dec
1
comment How do I install xen hypervisor + linux onto a usb memory stick
What have you tried so far? Most usb sticks just show up as a regular /dev/sdx, so you should be able to pick that as a drive and install onto it. If the installer does not want to work with a non-hdd, you can always make a ext{2,3,4} partition on the USB stick and make it boot with EXTLINUX, point it at the hypervisor, and let it boot.
Nov
28
comment TCP/IP & throughput between FreeNAS (BSD) server & other LAN machines
How fast is the read speed on the same file off the disk, without any network in the process? Lots of current-day hard drives have speed of about 70MB/sec for sequential reads, so maybe you're just bottlenecked on the disk?