1,413 reputation
1711
bio website redhardsupra.blogspot.com
location Laurel, MD
age 37
visits member for 5 years, 10 months
seen Mar 26 at 18:39

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?
Jul
21
comment Linux tmpfs having no effect on performance!
The kernel tends to be much smarter than your average sysadmin on determining what should be cached and what shouldn't. There's a whole lotta caching going on of stuff you don't really get to see from user's perspective. I tend to clear caches only for testing. For actual production, I'd leave it alone in 99% of cases. Or to quote Agent Smith: Never send a human to do a machine's job. ;)
Jun
28
comment How to mirror filesystems with millions of hardlinks?
Anything that works at a block level, not file-system level would probably be a huge improvement.
Jun
17
answered Figuring out memory hogging process in a Linux centos machine
Jun
15
comment Why would you use IPv6 internally?
These are all popular myths, here's the bit more info: IPv6's multicasting is mandatory for basic functionality: for example to do a IPv4's ping broadcast equivallent you ping6 to FF02::1 for all regular nodes, and FF02::2 for all routers. IPv6's IPSec does not change ANYTHING from IPv4. You don't get any security for free. Still gotta configure all the modes, and deal with key distribution. IPv6's autoconfiguration is utter junk; by default it's as insecure as MAC<->IPv4, and it does NOT hand out DNS. If you want DNS you gotta install DHCPv6, so no gain there.
Jun
12
answered Transfer between internal disks slows down for large files
Jun
8
awarded  Scholar
Jun
8
comment Why is a single drive much faster than 4 of them in RAID5?
gets the accept for guessing 'bad drive' correctly.
Jun
8
accepted Why is a single drive much faster than 4 of them in RAID5?
Jun
8
revised Why is a single drive much faster than 4 of them in RAID5?
added 1253 characters in body
Jun
8
comment Why is a single drive much faster than 4 of them in RAID5?
straight out of lspci: LSI Logic / Symbios Logic 53c1030 PCI-X Fusion-MPT Dual Ultra320 SCSI and Kernel driver in use: mptspi. I have upgraded the firmware on the controller, I'll try to retest some of these cases, just to see if it makes any difference.
Jun
8
comment Why is a single drive much faster than 4 of them in RAID5?
I know it's bad, but I don't think it's 8MB/sec bad, is it? That's kinda useless in today's world, when you can grab a USB enclosure with a $50 drive and get 30mb/sec out of it.
Jun
8
asked Why is a single drive much faster than 4 of them in RAID5?
Jun
1
answered Free alternative to NI Real-Time Hypervisor?