dd question (from man page)
by JD
Man page says:
...
fdatasync
physically write output file data before finishing
fsync likewise, but also write metadata
There is no explanation about this, as dd is supposed to be agnostic
about the type of the data.
If a disk is being dd'ed out to a file and the disk is mounted,
(which is a BAAAAD thing to do), then even there, dd is agnostic
about FS data and FS metadata.
So, what data and metadata is the manpage talking about?
9 years, 6 months
Port knocking script/server for fedora?
by William Oliver
I've been reading a bit about port knocking as a security tool. It makes pretty good sense for a private box, at least for stuff like ssh and ftp. Does anybody know of a good tutorial/example/script for fedora for this?
Thanks!
billo
9 years, 6 months
Multicast routing daemon
by Ian Pilcher
I'm looking for an (IPv4) multicast routing daemon for Fedora, and it
doesn't seems like there's anything out there.
Is this truly the case? (It just seems kind of hard to believe.)
--
========================================================================
Ian Pilcher arequipeno(a)gmail.com
-------- "I grew up before Mark Zuckerberg invented friendship" --------
========================================================================
9 years, 6 months
Lost my virtual desktop
by A.J. Bonnema
Hi all,
I run fedora 20 fully updated (on x64). I just renamed my .kde and
.kdevduchain to respectively .kde-old and .kde-vduchain-old. My goal was
to get the default desktop, and I did. However, in the process I lost my
virtual desktops. I find life in KDE pretty hard without my virtual
desktops.
I can't for the life of me find how to re instate the virtual desktops.
P.S. If any one knows what the vduchain is for, I would like to know
that too. But it's no biggie.
Can anyone help me get my virtual desktops back?
Kind regards, Guus.
9 years, 6 months
User friendly proxy configuration
by Jeandet Alexis
Hi,
I try to convince my colleagues to switch to Fedora as much as I can,
they all like it! But in my lab we connect through a web proxy and I
have to say that changing the config on both gnome and yum/dnf is quite
boring. Also new linux users are sometime afraid when I tell them "you
just need to edit the /etc/something.conf".
So my question is: Is there any way to have a centralised proxy config
with a simple GUI? Does some of you have some tricks?
I tried to look at some solution running a local light proxy on the
machine but it doesn't forward all the protocols. It also seems that DNF
and YUM doesn't accept pac files.
Best regards,
Alexis.
9 years, 6 months
SATA II causes system freeze
by David A. De Graaf
For several months I've been trying to track down the cause of
frequent system freezes on a machine I built in Dec. '13.
The frequency of freezes has gradually increased from never to several
times a day.
The solution is so improbable that I wonder if I am hallucinating.
I simply moved the SATA cable from a SATA 2 to a SATA 3 socket on the
motherboard.
There are two hard drives:
/dev/sdb - the primary ATA disk with several partitions that constitute
the working Fedora 20 system. This is a Western Digital WD 2500BB-00G
250 GB with old-style 40pin ATA ribbon cable to the ATA socket on
the mobo.
/dev/sda - the secondary SATA disk, a 1 TB Western Digital WD10EACS-00D.
This is used solely to save a backup image of another machine, updated by
rsync every night at 10:30 PM. It has a SATA connector and, according
to the newegg spec sheet, runs at 3.0Gb/s, which is SATA II. The SATA
III spec runs at 6.0Gb/s. Except for the nightly backup, this disk is
never used, or as Mr. James Clapper might say, never used "wittingly".
The imponderable questions are:
- why would plugging a SATA II disk into a SATA II socket produce
random freezes?
- why would plugging that SATA II disk into a SATA III socket NOT
produce freezes and work well?
- Is this behaviour indicative of defective SATA mobo sockets,
defective ata software, defective hard drive implementation?
Originally, I had used a Gigabyte 78MT-USB3 mobo, but replaced it with
an ASRock 960M/U3S3 FX mobo in a futile attempt to fix the problem.
For several months the original Gigabyte mobo worked fine - and then the
freezes began. These may be the only two available mobo's with both
the AM3+ cpu socket and an ATA disk socket. The Gigabyte mobo has only
SATA II sockets - 6 of them, while the ASRock has 2 SATA III and 4 SATA
II sockets.
For completeness, I've tested all four SATA II sockets. All cause system
freezes, one as quickly as 12 minutes, another as long as 20:27 hh:mm.
In contrast, use of either of the SATA III sockets yield a stable system.
When the system freezes, if X is lit (not screen-saved) the LCD
monitor looks as if it had been hit a sharp blow on the right edge so
that all the pixels have been shaken loose. All vertical lines are
shimmering off to the right or left in quarter inch blocks. The image
is still recognizable and almost readable. The NumLock key toggles
its LED, but not the ShiftLock or ScrollLock. No other keys are alive
including Alt-Fn-N, CTL-ALT-BS or CTL-ALT-Del. There's no mouse
action. The ethernet card LEDs blink, but pinging from another
machine fails. Only the Reset button, or the Power button, work.
Before stumbling onto the SATA II -> SATA III solution, here are some
things I tried, that failed:
- Replaced the motherboard (as noted).
- Added a second 4GB memory stick
- Ran memtest86 for a day and a half without a single error
- Watched the cpu temperatures and saw only normal values
- Cleaned and reseated the cpu and applied new thermal grease
- Disabled skype
- Unplugged a USB camera and microphone
- Removed a USB Logitech wireless kbd/mouse; replaced with wired ones
- Converted the ATA primary disk to SATA via an adapter. Although not
tested extensively, when plugged into a SATA II socket it ran OK.
So, wizards, has any of you experienced a system freeze such as mine?
Can you attribute it to connecting a SATA II hard drive to a SATA II
socket?
--
David A. De Graaf DATIX, Inc. Hendersonville, NC
dad(a)datix.us www.datix.us
Q: Why do programmers confuse Halloween and Christmas?
A: Because OCT 31 == DEC 25.
9 years, 6 months
Poor ext4 performance questions
by George R Goffe
Hi,
I have some large ext4 filesystems with large numbers of files in them and performance really sucks. After inactivity, a simple ls takes minutes to complete. I'm pretty sure the drive is now powering itself down due to this inactivity.
Are there tuning parameters that I could alter that would keep more of the filesystem meta data in memory? It looks like the data slowly migrates back to disk and as a result, takes minutes to fill back up enough to respond.
Regards and THANKS for your help and your time,
George...
9 years, 6 months
Out of the Broadcom frying pan (DELL) to the fire (HP Envy)
by Gary Stainburn
I've finally got my new laptop and I've managed to get F20 installed on it.
I've got a number of problems to work on yet - web cam and touch pad buttons -
but my main problem is the WIFI.
On the DELL I used broadcom-wl and kmod-wl and had to update it every time I
upgraded the kernel, but it worked,
Now I've got a newer Broadcom chipset on the replacement laptop and so far all
I can Google is people who've failed to get it working.
Can anyone point me to a post where it's worked. Below is the lspdi output.
Gary
[root@localhost ~]# lspci -nn -d 14e4:
08:00.0 Network controller [0280]: Broadcom Corporation BCM4352 802.11ac
Wireless Network Adapter [14e4:43b1] (rev 03)
[root@localhost ~]#
9 years, 6 months
Clearing the unallocated disk space
by JD
Before sending the drive for warranty service, what is the best way to
clean the unallocated blocks?
The rest of the files on disk are OK - standard installation, ... etc.
All home dirs are deleted, tmp dirs, logs ....etc all deleted.
If you can think of other things to delete, pls let the world know.
Thanx.
Thanx.
9 years, 6 months
HP Envy Touchpad button problems
by Gary Stainburn
Onwards and upwards. I'm going for a micro USB WIFI adaptor to fix my wireless
problem so I'm now moving onto my touchpad.
The problem I have is that unlike traditional touch pads the left and right
mouse buttons on this laptop are part of the touch pad itself. The problem
I'm experiencing here is that when I press the lower left or lower right
corner to activate the mouse buttons the mouse pointer also moves.
Does anyone have any suggestions?
One option for the left button is a single tap of the pad. This laptop is
(unfortunately) Win8 dual boot. In Win8, if I tap the middle of the touch
pad, it acts like a left button click. Is there any way to do the same in
Linux - I'm using F20 with KDE.
Also, on the DELL I had the following script which turned on 3-button
emulation.
Anyone got any suggestions how I could do this better on the HP?
#!/bin/bash
X='/usr/bin/xinput'
for F in `$X list|grep Logitech|cut -d = -f 2|cut -c1-3` ; do
$X set-prop $F "Evdev Middle Button Emulation" 1
done
Gary
9 years, 6 months
