Answered

Hi

I am trying to connect a reliance netconnect data card on my linux box (
cent os ) , i am able to the detect the device /dev/ttyUSB0

these are the following steps I did :

Check your card is recognized by the kernel
# cat /proc/bus/usb/devices

…..
…..
T: Bus=07 Lev=01 Prnt=01 Port=01 Cnt=01 Dev#= 11 Spd=12 MxCh= 0
D: Ver= 1.10 Cls=00(>ifc ) Sub=00 Prot=00 MxPS=64 #Cfgs= 1
P: Vendor=19d2 ProdID=fff5 Rev= 0.00
S: Manufacturer=ZTE, Incorporated
S: Product=USB Storage
S: SerialNumber=000000000002
C:* #Ifs= 1 Cfg#= 1 Atr=c0 MxPwr=100mA
I: If#= 0 Alt= 0 #EPs= 2 Cls=08(stor.) Sub=06 Prot=50
Driver=usbserial_generic
E: Ad=89(I) Atr=02(Bulk) MxPS= 64 Ivl=0ms
E: Ad=0a(O) Atr=02(Bulk) MxPS= 64 Ivl=0ms
…..
…..

i use the usb_modeswitch to detach it as a storage dev and attach it to a
usb dev

usb_modeswitch -v 0x19d2 -p 0xfff5 -d 1 19d2:fff5

usb_modeswitch -v 0x19d2 -p 0xfff5 -H 1

now i modprobe the usbserial

modprobe -v -r usbserial

modprobe -v usbserial vendor=0x12d1 product=0×1001

now do I do a dmesg

::::::::::::::::::
usbcore: deregistering driver usbserial_generic
drivers/usb/serial/usb-serial.c: USB Serial deregistering driver generic
usbcore: deregistering driver usbserial
usbcore: registered new driver usbserial
drivers/usb/serial/usb-serial.c: USB Serial support registered for generic
usbserial_generic 7-2:1.0: generic converter detected
usb 7-2: generic converter now attached to ttyUSB0
usbcore: registered new driver usbserial_generic
drivers/usb/serial/usb-serial.c: USB Serial Driver core

I edit the vi /etc/wvdial.conf

[Dialer Defaults]
Modem = /dev/ttyUSB0
Baud = 57600
Setvolume = 0
Dial-AT-OK ATDT Command =
Init1 = ZTE
FlowControl = Hardware (CRTSCTS)
Phone = #777
Username = 7228412233
Password = 7228412233
New PPPD = yes
Carrier Check = no
Stupid Mode = yes

When i try to detect the modem it gives me a failure

wvdialconf /etc/wvdial.conf

At this step, you should see success message to be able to connect a reliance netconnect data card .
If you still having problem, Recheck your configuration and test your wvdial.

I have a program that writes lots of files to a directory tree (around 15 Million fo files), and a node can have up to 400000 files (and I don’t have any way to split this ammount in smaller ones). As the number of files grows, my application gets slower and slower (the app is works something like a cache for another app and I can’t redesign the way it distributes files into disk due to the other app requirements).
The filesystem I use is ext3 with teh following options enabled:
Filesystem features: has_journal resize_inode dir_index filetype needs_recovery sparse_super large_file
Is there any way to improve performance in ext3? Would you suggest another FS for this situation (this is a prodution server, so I need a stable one) ?
Answer : n many ways this is similar to issues you’ll see in a very active mail ornews server that uses maildir wherein the d-entries get too large to betraversed quickly. The only way to deal with it (especially if theapplication adds and removes these files regularly) is to every once in awhile copy the files to another directory, nuke the directory and restorefrom the copy. This is why databases are better for this kind of intensivedata caching.

Click here more details to optimal filesystem

Getting this error message ?

Unable to resolve host address

This means that your linux system is failed to convert DNS or host name into ipaddress. To fix this, you need to check /etc/resolv.conf

/etc/resolv.conf should contain  list of nameserver with structure

nameserver nameserveraddress

nameserveraddress may contain hostname or ipaddress.

If you still have problem, contact me and put comment below.

Use this syntax to calculate concurrent Connection

netstat -an | grep ESTA | wc -l

If you want to calculate concurrent Connection on specific port

netstat -an | grep ESTA | grep 80 | wc -l

I hope this will help.

More Discussion at : Concurrent Connection