Jonathan Henson's questions

I have a disk, say /dev/sda.

Here is fdisk -l:

 Disk /dev/sda: 64.0 GB, 64023257088 bytes
255 heads, 63 sectors/track, 7783 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0000e4b5

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          27      209920   83  Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2              27         525     4000768    5  Extended
Partition 2 does not end on cylinder boundary.
/dev/sda5              27         353     2621440   83  Linux
/dev/sda6             353         405      416768   83  Linux
/dev/sda7             405         490      675840   83  Linux
/dev/sda8             490         525      282624   83  Linux

I need to make an image to store on our file server for use in flashing other devices we are manufacturing so I only want the used space (only about 4gb). I want to keep the mbr etc... as this device should be boot ready as soon as the copy is finished.

Any ideas? I previously had been using dd if=/dev/sda of=[//fileserver/file], but at that time, my master copy was on a 4gb flash ide.

I am thinking of switching our streaming servers to use multicasting instead of registering multiple clients and duplicating the streams manually on the server. It seems to work very well. However, I did notice that on the packet capture, when a server is multicasting the packets show up on every node, even those that have not subscribed to the stream. Is this the way it is supposed to function? Will this cause network problems if I have several of these servers sending out a multicast stream simultaneously(to different addresses obviously)?

thanks!

Our DNS/Active Directory/file server crashed a couple of days ago. I rebuilt the machine and reinstalled Active Directory yesterday.

Now none of the linux machines on our network have internet connections. I have checked the kernel routing tables, domain names, resolv.conf files, etc... They all seem fine. I can also ping the DNS server (on our LAN) and the router, but all pings outside the LAN fail.

Everything was fine before the failure.

All windows machines are fine. Any ideas?

Tracepath 8.8.8.8:

1: LINUS.innovisit.com
2:  no reply
... 
...
same forever

nslookup google.com

Server: 192.168.0.200
Address: 192.168.0.200#53

Non-Authoritative answer:
Name: google.com
74.125.130.102
... 
...
googles other 6 ips

nslookup innovisit.com

Server: 192.168.0.200
Address: 192.168.0.200#53

Name: innovisit.com
Address: 192.168.0.200

Now innovisit.com is also our company domain name, I don't know if that makes a difference. When I ping it, it gives me our local ip address of the machine running active directory instead of the public ip address that our domain is pointing to.

Also, I just noticed that if I do an ifupdown on eth0, I will get an internet connection for a minute or two, then I lose it again.

I have an SIP endpoint, which I wrote, that receives sip invites, processes them, replies, and sets up the rtp session just fine when contacted directly.

i.e.

sip:user@[actual ip address of endpoint]

However, if I try and route through the registrar, it never replies. If it does reply, it responds with Bad Request. I have looked at the request and everything is fine, so it isn't malformed (at least when it is sent).

Yet, if the end point in question originates the call, everything works perfect.

I am testing with ekiga, just to take my code out of at least half of the equation.

Here is the request:

INVITE sip:[email protected] SIP/2.0
Date: Mon, 21 May 2012 15:42:26 GMT
CSeq: 1 INVITE
Via: SIP/2.0/UDP 192.168.0.22:5060;branch=z9hG4bK21b00fb7-1707-1910-92f3-0025b360b492;rport
User-Agent: Ekiga/3.2.7
From: "Jonathan" <sip:[email protected]>;tag=c9ad0fb7-1707-1910-92f1-0025b360b492
Call-ID: c9ad0fb7-1707-1910-92f2-0025b360b492@HOWIE
To: <sip:[email protected]>
Contact: <sip:[email protected]>
Allow: INVITE,ACK,OPTIONS,BYE,CANCEL,SUBSCRIBE,NOTIFY,REFER,MESSAGE,INFO,PING
Content-Type: application/sdp
Content-Length: 566
Max-Forwards: 70

v=0
o=- 1337614946 1 IN IP4 192.168.0.22
s=Opal SIP Session
c=IN IP4 192.168.0.22
t=0 0
m=audio 5084 RTP/AVP 0 8 101
a=sendrecv
a=rtpmap:0 PCMU/8000/1
a=rtpmap:8 PCMA/8000/1
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-16,32,36
m=video 5086 RTP/AVP 109 108 34
b=AS:4096
b=TIAS:4096000
a=sendrecv
a=rtpmap:109 h264/90000
a=fmtp:109 packetization-mode=1;profile-level-id=42C01E
a=rtpmap:108 h263-1998/90000
a=fmtp:108 D=1;F=1;I=1;J=1;CIF=1;CIF4=1;QCIF=1;CUSTOM=320,240,1;CUSTOM=640,480,1
a=rtpmap:34 h263/90000
a=fmtp:34 F=1;CIF=1;CIF4=1;QCIF=1

The end point registers just fine as I can see it from the registrar as registered.

Also, the software for the endpoint is working, because I have it running on my desktop as well and everything works as I expect.

also, netstat -lvuwp shows that my application is listening on port 5060 as it should.

update I just noticed that the registrar is not translating the request the final part of the way. I see it receive the request in wireshark, say 192.168.0.22 -> 192.168.0.200 (the registrar's address) but I never see 192.168.0.200 -> 192.168.2.5 (the end point in question) as it does on the other endpoints.

Here is the attempted forward from the registrar to the endpoint

INVITE sip:[email protected];q=1, <sip SIP/2.0
Via: SIP/2.0/UDP 192.168.0.200:5060;branch=z9hG4bK-5bbc7711b807109;rport
Via: SIP/2.0/UDP 192.168.0.22:5060;branch=z9hG4bK5bb8b0c7-1707-1910-9366-0025b360b492;received=192.168.0.22;rport=5060
Date: Mon, 21 May 2012 16:28:56 GMT
CSeq: 1 INVITE
From: "Jonathan" <sip:[email protected]>;tag=03b6b0c7-1707-1910-9364-0025b360b492
Call-ID: 03b6b0c7-1707-1910-9365-0025b360b492@HOWIE
To: <sip:[email protected]>
Contact: <sip:[email protected]>
Allow: INVITE,ACK,OPTIONS,BYE,CANCEL,SUBSCRIBE,NOTIFY,REFER,MESSAGE,INFO,PING
Max-Forwards: 69
Record-Route: <sip:192.168.0.200;lr>
User-Agent: Ekiga/3.2.7
Content-Type: application/sdp
Content-Length: 566

v=0
o=- 1337617736 1 IN IP4 192.168.0.22
s=Opal SIP Session
c=IN IP4 192.168.0.22
t=0 0
m=audio 5066 RTP/AVP 0 8 101
a=sendrecv
a=rtpmap:0 PCMU/8000/1
a=rtpmap:8 PCMA/8000/1
a=rtpmap:101 telephone-event/8000
a=fmtp:101 0-16,32,36
m=video 5068 RTP/AVP 109 108 34
b=AS:4096
b=TIAS:4096000
a=sendrecv
a=rtpmap:109 h264/90000
a=fmtp:109 packetization-mode=1;profile-level-id=42C01E
a=rtpmap:108 h263-1998/90000
a=fmtp:108 D=1;F=1;I=1;J=1;CIF=1;CIF4=1;QCIF=1;CUSTOM=320,240,1;CUSTOM=640,480,1
a=rtpmap:34 h263/90000
a=fmtp:34 F=1;CIF=1;CIF4=1;QCIF=1

anyone see the problem? My suspicion is that the problem is with the ;q1, <sip that doesn't look like it belongs.

update

I noticed this line

[Contact] = <sip:[email protected]:5060>;q=1, <sip:vs005@[fe80::230:18ff:feab:100e]:5060>;q=0.500

from the REGISTER for my endpoint the ;q=1, <sip text made me think that the sip server is having trouble parsing ipv6. So, I turned off ipv6 on the endpoint and voila! everything is fine.

I am currently trying to get the following scenario to work.

Warning: I am a software engineer--not a network admin.

I have various SIP endpoints (sip based video servers) on a LAN. On a Windows Server on that LAN, I have tekSIP running as the SIP Registrar. All of this works so far. I can register from the endpoints with the registrar and make calls just fine.

Now I want to allow remote calls from outside our LAN. First, I put an A entry in our dns: "sip" which resolves to our external ip. I setup an SRV record for _sip._udp.sip.ourdomain.com. If I ping sip.ourdomain.com, everything works, the dns resolves to our public ip and the ping works. Everything also looks good in nslookup.

On our router, I forwarded port 5060 for udp to the server running tekSIP. Here is where the problem comes in. If I try to register or make a call from a remote endpoint, it always fails, and I can't even see the incoming request in wireshark on the application server.

Any ideas? I would be happy to post any config files you request.

I have an embeded system which I finally got stable by doing multiple partitions like so:

Disk /dev/sda: 4017 MB, 4017807360 bytes
255 heads, 63 sectors/track, 488 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0000e4b5

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *           1          25      194560   83  Linux
Partition 1 does not end on cylinder boundary.
/dev/sda2              25         489     3726337    5  Extended
Partition 2 does not end on cylinder boundary.
/dev/sda5              25         329     2440192   83  Linux
/dev/sda6             329         377      386048   83  Linux
/dev/sda7             377         456      633856   83  Linux
/dev/sda8             456         462       51200   83  Linux
/dev/sda9             463         489      210944   82  Linux swap / Solaris

The problem, when I did this, I upgraded the kernel and software packages and the software does not perform near as well. Now I want to revert back to a version that was partitioned like so:

Disk /dev/sda: 4017 MB, 4017807360 bytes
98 heads, 57 sectors/track, 1404 cylinders
Units = cylinders of 5586 * 512 = 2860032 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x0008aff7

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1               1        1405     3921920   83  Linux

Here is the way I want the mount points:

rootfs on / type rootfs (rw)
sysfs on /sys type sysfs (rw,nosuid,nodev,noexec,relatime)
proc on /proc type proc (rw,nosuid,nodev,noexec,relatime)
udev on /dev type devtmpfs (rw,relatime,size=1546156k,nr_inodes=216373,mode=755)
devpts on /dev/pts type devpts (rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmod
e=000)
/dev/disk/by-uuid/3882d0e8-bdc0-49ef-a62a-9208ae70ce9b on / type ext3 (ro,noatim
e,errors=remount-ro,barrier=0,data=ordered)
tmpfs on /lib/init/rw type tmpfs (rw,nosuid,relatime,mode=755)
tmpfs on /dev/shm type tmpfs (rw,nosuid,nodev,relatime)
/dev/sda7 on /home type ext3 (rw,noatime,errors=continue,barrier=0,data=ordered)
/dev/sda8 on /tmp type ext3 (rw,noatime,errors=continue,barrier=0,data=ordered)
/dev/sda5 on /usr type ext3 (rw,noatime,errors=continue,barrier=0,data=ordered)
/dev/sda6 on /var type ext3 (rw,noatime,errors=continue,barrier=0,data=ordered)
fusectl on /sys/fs/fuse/connections type fusectl (rw,relatime)
gvfs-fuse-daemon on /home/hhp/.gvfs type fuse.gvfs-fuse-daemon (rw,nosuid,nodev,
relatime,user_id=1000,group_id=1000)

I have the dd of the older O.S., how can I do this?

I have an embedded system I have been developing. I would like to bind a program called HHPConfig, which I wrote and needs root permissions for setting network interfaces, rebooting etc..., to a user, admin, which can log in through telnet and rs232.

I edited the line in /etc/passwd to be:

admin:x:1001:1001:Admin User,,,:/home/admin:/usr/bin/HHPConfig

I also added the user to the group sudo.

I don't know what to do past there.

I have an embedded linux system. I use grub2 for the boot loader. I would like to run an fsck -y /dev/sda on /dev/sda every time it boots--even when the system had a power loss and the reboot command was not used. How can I do this?

I have an embeded linux video server that I just finished. One of the features is that I have a telnet server as well as getty bound to an rs232 port which a user can log into to call a few programs which I have written for server configuration purposes. This is intended to be a backdoor for users if for some reason, the SDK I developed isn't working or they just bought the server and don't have a programmer to put the SDK to use. There is also a web interface, but whatever, the spec says I have to have one.

So for instance, I wrote a program called getIp which allows a user to retrieve network settings and setIp which allows them to set the IP. I have a similar program or script for every function that my .NET based API already does.

However, I do not want them to be able to run any programs other than these. i.e. I don't even want 'ls' or 'cd' to work. I would give them a user name, say "admin", to login to the session with. The question is, how do I setup these restrictions?

I have some embedded boards running American Megatrends bios with embedded linux as the OS. The problem I have is that the industrial flash ide's will be corrupted on power loss. I have them formatted as ext4. Whenever this happens, I can usually fix the flash with fsck, but this will not be possible in our deployments. I have heard that disabling the write-caching should help, but I can't figure out how to do it. Also, is there any thing else I should do?

More Info

The drive is a 4gb ide flash module. I have one partition which is ext4. The O.S. is installed on that partition and grub is my bootloader.

fdisk -l shows /dev/sda as my flash module with /dev/sda1 as my primary partition.

After a power loss I usually cannot make it entirely through the boot init scripts.

When I mount the drive on another P.C. I run fsck /dev/sda1. It always shows messages like

"zero datetime on node 1553 ... fix (y)?"

I fix them and it boots fine until the next power loss.

When I get to the office tomorrow, I will post the actual output of fdisk -l

This is all I know about how the system works. I am not a systems guy, I am a Software Engineer that has a habit of getting into predicaments that are outside of his job description. I know how to format drives, install a bootloader, write software, and hack on an operating system.

Here is the output from dumpe2fs

#sudo dumpe2fs /dev/sda1
dumpe2fs 1.41.12 (17-May-2010)
Filesystem volume name:   VideoServer
Last mounted on:          /
Filesystem UUID:          9cba62b0-8038-4913-be30-8eb211b23d78
Filesystem magic number:  0xEF53
Filesystem revision #:    1 (dynamic)
Filesystem features:      ext_attr resize_inode dir_index filetype extent flex_bg sparse_super large_file huge_file uninit_bg dir_nlink extra_isize
Filesystem flags:         signed_directory_hash 
Default mount options:    (none)
Filesystem state:         not clean
Errors behavior:          Continue
Filesystem OS type:       Linux
Inode count:              245760
Block count:              977949
Reserved block count:     48896
Free blocks:              158584
Free inodes:              102920
First block:              0
Block size:               4096
Fragment size:            4096
Reserved GDT blocks:      239
Blocks per group:         32768
Fragments per group:      32768
Inodes per group:         8192
Inode blocks per group:   512
Flex block group size:    16
Filesystem created:       Fri Feb  4 15:12:00 2011
Last mount time:          Sun Oct  2 23:48:37 2011
Last write time:          Mon Oct  3 16:34:01 2011
Mount count:              2
Maximum mount count:      26
Last checked:             Tue Oct  4 07:44:50 2011
Check interval:           15552000 (6 months)
Next check after:         Sun Apr  1 07:44:50 2012
Lifetime writes:          21 GB
Reserved blocks uid:      0 (user root)
Reserved blocks gid:      0 (group root)
First inode:              11
Inode size:           256
Required extra isize:     28
Desired extra isize:      28
Default directory hash:   half_md4
Directory Hash Seed:      249d2b79-1e20-49a3-b324-6cb631294a63
Journal backup:           inode blocks

I am currently working on an embed linux video server. When I deployed the application to the boards we are planning on using for production I noticed that the audio was noisy.

I discovered that the audio capture is supposed to be grabbing 640 bytes of data (16 khz, 1 channel, with 16 bit width @ 20 ms per buffer). However regardless of how I grab the data, it always returns 682 bytes, which is, assuming, that I am achieving the sample rate, 21.3 ms of data.

I thought, ok, maybe this is just an alsa problem, so I tried pulse... same problem. Then I tried using PTLib grabbing straight from the sound card ... same problem. I know the code is right (hence the reason the question is here and not on stack overflow). What should I be looking for to solve this problem?

It has to be exactly 20 ms of data for me to pass to the rtp stream for the purposes of the jitter buffer. Any ideas?

The sound card is an Integrated Realtek ALC888 6-channel HD audio codec.

I currently have an embedded video server that I developed using embed linux, c and c++. I currently have our assembly line workers flash the ide drives from a usb flash drive like so:

dd if=/dev/sdb1 of=/dev/sda1.

Yesterday, I accidentally erased one of my new versions of the O.S. and software when I reversed IF and OF. Anyhow, I decided to start storing a copy of the firmware to our fileserver so, 1. They don't need to use the usb flash drives anymore (very slow), then they could just use the file server's file in the flash and 2. I don't accidentally erase one of my dev images again.

My question is a simple one. 1st, is there a better way to do this? 2nd, As I am currently doing it, should I use a file extension and what should it be?

Edit

Also, can I do the flash in such a way that it copies over the mbr? I am tired of installing grub on each ide.