Netgear AC750 Wifi Range Extender (EX3700)
Here is how I satisfied my need to have a LAN messaging program, not really to chat with other users on the same LAN, which I could do, but to copy and paste links or texts between a rdp client and a rdp server when copy and paste from/to clipboard does not work in rdp sessions, for instance with some Android rdp clients.
These are the programs I used:
- Openfire 3.9.3 on the "server" (which can be a simple Windows pc): a realtime collaboration server using XMPP/Jabber
- Miranda IM 0.10.23.0: a multi-protocol instant messaging client
- Xabber 0.9.30b: an Android Jabber client
Recover "Logical sector size is 0" with dd
A few hours ago while I was using my pc suddenly Windows froze completely (mouse was stuck and Ctrl+Alt+Del did nothing). It's not astonishing but I was quite surprised because such a freeze never happened since I began using Windows XP on my new pc.
The problem appeared at the reboot:
grub, the bootloader on /dev/sda, showed this error message:
At reboot I started Windows XP Recovery Console from the Windows CD and tried
CHKDSK.EXE, and this was the outcome:
I booted again linux to launch
fsckand see it fail:
Then I found the solution in ubuntu forum:
root@am2:/home/z24# dd if=/dev/hda1 of=/defmedia/bkup_fat32_hda1.img bs=512 count=2048000 conv=noerror,sync 2048000+0 records in 2048000+0 records out 1048576000 bytes (1.0 GB) copied, 43.61 seconds, 24.0 MB/s root@am2:/home/z24# dd if=/defmedia/bkup_fat32_hda1.img of=/home/z24/sector6.bin bs=512 count=1 skip=6 conv=noerror,sync 1+0 records in 1+0 records out 512 bytes (512 B) copied, 0.011544 seconds, 44.4 kB/s root@am2:/home/z24# dd if=/home/z24/sector6.bin of=/dev/hda1 bs=512 count=1 conv=noerror,sync,notrunc 1+0 records in 1+0 records out 512 bytes (512 B) copied, 0.030644 seconds, 16.7 kB/sExplanation:
- the first dd makes a backup of the first gigabyte of the Windows partition: I copied 1 GB only because I didn't have enough space on a ext2fs to backup all the 28 GB of /dev/hda1.
- the second dd extracts the sixth sector to a temporary file: as reported by Microsoft KB247575, "The backup FAT32 boot sector is located at sector 6 of the logical drive".
- the third
ddcopies the extracted sector 6 to sector 0 of /dev/hda1.
ddwas also checked with
mount. Thanks a lot to the ubuntuforums user Onlymee for his post!
Update 13.09.2008The same problem happened again today and gave me the opportunity to complete the series of error messages :)
The first, at boot time, was the same: Mounting the partition (
mount -t vfat /dev/sda1 /mnt):
dmesg | grep sda1But
fdisk -l /dev/sdashows the partition table.
fsck.vfat /dev/sda1(executed from Ubuntu 8.04 alternate cd) The solution was exactly the same: copy the sixth sector back to the first. And voilà, it booted.