Archive for January, 2008
asus p5b se… linux 32bit and 6gigs of RAM… wtf?
huh…
I upgrated ram in Aquarius Server… Because ddr2 price is really cool for now (107PLN), I bought 2 modules (thanks for sponsor of one - xoff 
) containing 2GB each. And so the story begun
After booting the 2.6.22 PLD kernel the system was tooootaly slow (like a turtle ). I asked - WHY? PLD Linux dist kernel does have
CONFIG_HIGHMEM4G
set up. Ok… so I build a spec with high mem enabled
CONFIG_HIGHMEM64G=y
and… nothing has changed, after experiments with ‘mem’ grub parameter I noticed that only if I set 4GB it works properly and fast… ok, I build another egg with PAE enabled… no difference (you can find this kernel in new section “packages“)
Everybody at #pldhelp channel suggested installing 64bit version of PLD (TH release).
I tried to boot up a 64bit pld rescue cd… but - it hung at
checking if image is initramfs…
I removed ram, and left only 2GB, installed TH (thanks for xoff )… and… nothing has changed… WTF i thought. I scanned the ram by memtest86… no errors. OK… google… google…google
Two interesting articles:
From ubuntu forum
Both suggested updating bios, but the problem dealt with gigabyte mainboard. As Ahmed said “what do I care - I’m dead :)”, I tried to find the new bios, but in release note was only an information about “new cpu support”. But as I said “what do I care :)”… I did a BIOS update (with eZ flash utility built in asus bios, which can update the bios with .rom file located at cdrom, floppy or pendrive). And - everything is OK :).
The system starts perfectly fast… and… take a look at this:
MemTotal: 5805668 kB
but i found in cat /proc/meminfo something like this:
VmallocTotal: 34359738367 kB … nice… 34 349 GB of what?
the answer is here
now I have a doubt to consider… use ac with 32bits or unstable th with 64bits
why cifs is so slow when mounting through the wan and vpn
Today I mounded some samba shares through the vpn (because of fact copying over 200GB of data, and quite easy method). I thought that using it will be easier to use in rsync. But I was totttaaalllyyy wrong 
mount -t cifs //10.10.5.13/test /store/test –verbose -o user=test -o directio -o rsize=200000 -o wsize=200000
rsync -avz -P /store/test/test.tar.bz2 /store/test_backup/
test.tar.bz2
5799936 0% 87.15kB/s 18:03:01
rather poor transfer when we have a 5mbps link, don’t you think so?
test another file from same server, but through http…
$ wget 10.10.5.13/100mb.test
–16:40:45– http://10.10.5.13/100mb.test
=> `10.10.5.13/100mb.test.2′
Connecting to 10.10.5.13|:80… connected.
HTTP request sent, awaiting response… 200 OK
Length: 102,400,100 (98M) [text/plain]2% [=> ] 2,123,712 567.60K/s ETA 02:56
The difference is almost 6 times. I google a lot to find the solution, because I thought that I have some error in my configuration or something. But I found only questions, with no answers. So I would like to sumarize what I found.
When CIFS was originally developed, users and applications were situated in close proximity and most network traffic stayed local to the user. In that environment, CIFS works quite well. According to Nemertes Research, more than 80% of users now work outside the organization headquarters.
Three reasons of the poor cifs quality:
1. CIFS is a “chatty” protocol that often requires hundreds of round trips between file server and user in order to complete the original request to transport the file. These round trips are not noticeable in a LAN, but they introduce significant latency (delayed response time) across long distance WAN links.
2. To protect against data loss when a user is working on a file, many applications will do periodic automatic saves of work in progress. CIFS does its part by sending complete updates of the files back to the file server. While this preserves file integrity, it also exacerbates WAN congestion and performance delays because CIFS transports a
significant amount of redundant information.
3. WAN bandwidth is obviously far more limited and far more expensive than LAN bandwidth. Therefore, as more users and application traffic traverses WAN links
The net impact of the CIFS performance problem is unacceptably slow application response time experienced by remote users. Depending on the file size, WAN link, and other variables, the delays could be significant. In fact, it is not uncommon for a remote user to wait 15 minutes or more for a large file to be delivered to his or her desktop. When that “wait time” is experienced by hundreds of users spread out across dozens of locations, the CIFS performance problem becomes a severe business and user productivity
problem that must be fixed ASAP. But how?
For now - this question has no answer… but maybe in future?
new page: Packages
ok… now you can find a new page called “packages”. You can find there (for now, I’m just going to copy interesting builds to www server) my PLD Linux builds (from spec or not only), with some extra options enabled.
Any doubts: go to —> HERE
my fight with lighttpd at PLD Linux
Configuration of apache was easy (maybe because of the fact I made it many times), but apache is big like an elephant. I just want to serve dir indexes, so i didn’t need apache :). I tried to install lighttpd… and so the story goes:
Installation environment:
PLD AC 2.0 with ac, ac-updated, ac-supported and ac-ready packages
Lighttpd (today latest dist version is 1.4.18-8)
in poldek paste:
install lighttpd
and press enter
lighttpd in PLD has some dependencies which are installed with main package:
lighttpd-mod_dirlisting - generates HTML based directory listings with full CSS support
lighttpd-mod_indexfile - module for choosing index files
lighttpd-mod_staticfile - module for static file serving
webapps - is a package for having web applications configuration files and webserver config fragments in unified place
and it’s all…
/sbin/service lighttpd start
and you can check:
http://yourhost.com/
ok, but we need some more functions
first let’s check what we can muff
open in your favorite editor this file
/etc/lighttpd/lighttpd.conf
some description:
server.tag = “lighttpd super server”
you can change your server introduce
server.port = 80
if you want your server to use non standard port - change this option
really cool and standard option is trafic shaping (starting with version 1.3.8)
connection.kbytes-per-second = xy
limits the throughput for each single connection to the given limit in kbyte/s
and
server.kbytes-per-second = xx
limits the throughput for all connections
ok… maybe we need an ssl…
lighttpd supports SSLv2 and SSLv3, so the only thing we have to do is:
poldek -i lighttpd-ssl
make a self-signed certificate:
openssl req -new -x509 -keyout server.pem -out server.pem -days 365 -nodes
and move it to the default lighttpd place
mv server.pem /etc/lighttpd/
to finish installation just restart the lighttpd
short scp howto (from linux shell)
I have problem to remember the syntax of scp command… maybe it will be easier to find:
so… MARCIN - if you want to copy a file from remote server to local folder:
scp user@remotelocalisation.com:path_to_the_file_or_sth local_file
if you want to copy a file from local dir to remote server you have to use a command:
scp local_file username@remoteserver.com:path_to_the_folder/file
remove all hashes (#) from config files
Nice tip - how to remove all hashes from config (or another files).
I know just two methods, but this one I find best:
grep -v ‘^#’ file > file.new
second one (this one overwrite the main file):
sed -e ‘/^#/d’ -i file
you can even use vim, but it will remove all lines with #, not starting from hash.
:g/pattern/d
where the fuc*** is smbmount?
The version of samba has been chanded (3.xxxx), and the smbmount command has been depreciated. I noticed that fact, about 5-6 months ago, but I’ve never need this option at all.
I have to connect two linux machines, and I have to use the samba protocol… so… the answer is CIFS
Centos 5 and PLD Linux has cifs in its kernels, so you can easly use command like this:
[root@nitrogen ~]# mount -t cifs //10.10.10.63/testcase /mnt/test –verbose -o user=test
parsing options: rw,user=test
Password:
here you have to give the password :), and after successful login you should get sth like this:
mount.cifs kernel mount options unc=//10.10.10.62\testcase,ip=10.10.10.62,pass=secretpass,ver=1,rw,user=test
I’m a member of IBM technical expert community :)
Huh… I have just opened my mailbox (yes yes this normal one - with paper letters ), and I finally got my paper version of the IBM System Connect certificate
You can find the scans below…
gg servers status part 2
Ok, just checking if server is up… was not good idea. I optimized the script, just to inspect the port 8074. It is enough - I’m still waiting for a full list of gg servers from tech service of gg.
It was a good way to smatter bash scripting and html
You can see how does it work: gg_stats (in html looks better (thx for Zysio))