The Linux Questions Thread: a bunch of pitfalls, but technically it's possible

The Something Awful Forums > Discussion > Serious Hardware/Software Crap > The Linux Questions Thread: a bunch of pitfalls, but technically it's possible

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JHVH-1: Jun 28, 2002

Yeah the default on CentOS is LABEL=/ LABEL=/boot LABEL=swap-sda2 or whatever. The swap is based off the partition, but if the device changes the label doesn't so it still works. Its a hell of a lot easier to relabel something from a livecd if you need than to type out a UUID.

# ? Aug 19, 2009 10:33

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# ? May 10, 2024 14:45

inignot: Sep 1, 2003; WWBCD?

I've got a question regarding encrypted partitions in Fedora 11. I've set up an encrypted partition (/priv) during the install and I'm prompted for a password at each boot. Is there any way to either not mount /priv at boot or have the password prompt timeout? I don't expect to have physical access to the box every time it boots. I'd like to have the option to boot with /priv inaccessible and then mount & provide a password in a ssh shell later.

Google has turned up nothing good. This scenario isn't addressed here:
http://docs.fedoraproject.org/install-guide/f11/en-US/html/apcs02s02.html

And while this looks promising, the noauto and timeout options described are not present in the man crypttab on Fedora 11.
http://www.jezebelle.org/~pagan/phpMan.php/man/crypttab/5

Suggestions welcome.

# ? Aug 19, 2009 18:43

deedee megadoodoo: Sep 28, 2000; Two roads diverged in a wood, and I, I took the one to Flavortown, and that has made all the difference.

inignot posted:

I've got a question regarding encrypted partitions in Fedora 11. I've set up an encrypted partition (/priv) during the install and I'm prompted for a password at each boot. Is there any way to either not mount /priv at boot or have the password prompt timeout? I don't expect to have physical access to the box every time it boots. I'd like to have the option to boot with /priv inaccessible and then mount & provide a password in a ssh shell later.

Google has turned up nothing good. This scenario isn't addressed here:
http://docs.fedoraproject.org/install-guide/f11/en-US/html/apcs02s02.html

And while this looks promising, the noauto and timeout options described are not present in the man crypttab on Fedora 11.
http://www.jezebelle.org/~pagan/phpMan.php/man/crypttab/5

Suggestions welcome.

Can't you just umount the filesystem and remove it from fstab? Or if you still want it in fstab but not automounted, use the noauto option.

# ? Aug 19, 2009 19:16

inignot: Sep 1, 2003; WWBCD?

I commented out the line for mouting /priv in fstab:

code:

#/dev/mapper/luks-35f243b5-70fb-4e6d-ae45-f7b1a8bd1ed9 /priv                   ext4    defaults        1 2

Upon rebooting I'm prompted for a password to /sda5 instead of /priv.

The 'noauto' option in the crypttab man page at http://www.jezebelle.org/~pagan/phpMan.php/man/crypttab/5 seems like the obvious solution. However, the man page for crypttab on Fedora 11 doesn't list the same set of options. Here is what my crypttab man page offers:

code:

The fourth field, if present, is a comma-delimited list of options.  The following options are recognized:

       cipher=cipher
              Specifies the cipher to use; see cryptsetup(8) for possible values and the default value of this option.  A cipher with unpredictable IV  values,
              such as aes-cbc-essiv:sha256, is recommended.

       size=size
              Specifies the key size in bits; see cryptsetup(8) for possible values and the default value of this option.

       hash=hash
              Specifies the hash to use for password hashing; see cryptsetup(8) for possible values and the default value of this option.

       verify If the the encryption password is read from console, it has to be entered twice (to prevent typos).

       swap   The  encrypted  block  device  will  be  used as a swap partition, and will be formatted as a swap partition after setting up the encrypted block
              device.  The underlying block device will be formatted again as an unencrypted swap partition after destroying the encrypted block device.  (This
              allows  sharing a single swap partition between operating system installations, with some of them encrypting the swap partitions and some of them
              not.)

              WARNING: Using the swap option will destroy the contents of the named partition during every boot, so make sure the underlying  block  device  is
              specified correctly.

       tmp    The  encrypted  block device will be prepared for using it as tmp partition: it will be formatted using mke2fs and its root directory will be set
              to mode 01777.  The warning about the swap option applies here as well.

# ? Aug 19, 2009 19:40

dont skimp on the shrimp: Apr 23, 2008

Instead of commenting out it from fstab, just try adding noauto to it.
/dev/mapper/luks-35f243b5-70fb-4e6d-ae45-f7b1a8bd1ed9 /priv ext4 defaults,noauto 1 2

# ? Aug 19, 2009 19:57

deedee megadoodoo: Sep 28, 2000; Two roads diverged in a wood, and I, I took the one to Flavortown, and that has made all the difference.

Maybe try to use it even though it's not documented? I dunno. I was just taking a stab in the dark. Never worked with encrypted disks before.

# ? Aug 19, 2009 20:02

inignot: Sep 1, 2003; WWBCD?

Adding the 'noauto' to fstab does indeed prevent /priv from being mounted, however I'm still prompted for the password and /dev/sda5 is unlocked.

I think crypttab is processed before fstab. I'll see what happens if I put 'noauto' in the crypttab, even though support for this is questionable.

First time down the encrypted partition path for me.

code:

[root@localhost testuser]# cat /etc/fstab | grep noauto
 /dev/mapper/luks-35f243b5-70fb-4e6d-ae45-f7b1a8bd1ed9 /priv                   ext4    noauto          1 2


[root@localhost testuser]# mount
/dev/sda2 on / type ext4 (rw)
proc on /proc type proc (rw)
sysfs on /sys type sysfs (rw)
devpts on /dev/pts type devpts (rw)
/dev/sda1 on /boot type ext3 (rw)
tmpfs on /dev/shm type tmpfs (rw,rootcontext="system_u:object_r:tmpfs_t:s0")
none on /proc/sys/fs/binfmt_misc type binfmt_misc (rw)
sunrpc on /var/lib/nfs/rpc_pipefs type rpc_pipefs (rw)


[root@localhost testuser]# cat /etc/crypttab           
luks-35f243b5-70fb-4e6d-ae45-f7b1a8bd1ed9 UUID=35f243b5-70fb-4e6d-ae45-f7b1a8bd1ed9 none


[root@localhost testuser]# cryptsetup status luks-35f243b5-70fb-4e6d-ae45-f7b1a8bd1ed9
/dev/mapper/luks-35f243b5-70fb-4e6d-ae45-f7b1a8bd1ed9 is active:
  cipher:  aes-xts-plain
  keysize: 512 bits
  device:  /dev/sda5
  offset:  4040 sectors
  size:    2605443119 sectors
  mode:    read/write
[root@localhost testuser]#

# ? Aug 19, 2009 20:32

inignot: Sep 1, 2003; WWBCD?

Looks like I have it under control. I moved crypttab to crypttab.backup and then commented the line for mounting /priv out of fstab.

I can boot with no password prompt.

Once logged in I can unlock the encrypted /dev/sda5 and mount it as /priv manually.

cryptsetup luksOpen /dev/sda5 UUID=35f243b5-70fb-4e6d-ae45-f7b1a8bd1ed9
mount -t ext4 /dev/mapper/UUID=35f243b5-70fb-4e6d-ae45-f7b1a8bd1ed9 /priv

# ? Aug 19, 2009 21:18

Junji Eat More: Oct 22, 2005; You don't know it, but you are full of stahs

This is more of a security question, but I just built a server for our office (samba shares, hosts a wiki, nothing fancy), with remote SSH access, and I've been noticing the logfiles always have something like this every day:

sshd:
Authentication Failures:
unknown (112.78.119.179): 9423 Time(s)
unknown (62.63.48.40): 460 Time(s)
unknown (202.183.178.140): 120 Time(s)
root (202.183.178.140): 15 Time(s)
....another 100 or so attempts at various service names
testuser (62.63.48.40): 1 Time(s)
uucp (202.183.178.140): 1 Time(s)
Invalid Users:
Unknown Account: 10012 Time(s)

Nobody's getting access, but I'm noticing that there are attempts on actual users that I've made for samba access. I've locked their logins and redirected their shells to null, so I'm not worried about that, but are these outside attempts somehow finding my user names, or are they just brute-forcing commonly used ones? They are pretty common ones (accounting, sales, etc.).

# ? Aug 20, 2009 19:20

deedee megadoodoo: Sep 28, 2000; Two roads diverged in a wood, and I, I took the one to Flavortown, and that has made all the difference.

Necronomiconomist posted:

This is more of a security question, but I just built a server for our office (samba shares, hosts a wiki, nothing fancy), with remote SSH access, and I've been noticing the logfiles always have something like this every day:

sshd:
Authentication Failures:
unknown (112.78.119.179): 9423 Time(s)
unknown (62.63.48.40): 460 Time(s)
unknown (202.183.178.140): 120 Time(s)
root (202.183.178.140): 15 Time(s)
....another 100 or so attempts at various service names
testuser (62.63.48.40): 1 Time(s)
uucp (202.183.178.140): 1 Time(s)
Invalid Users:
Unknown Account: 10012 Time(s)

Nobody's getting access, but I'm noticing that there are attempts on actual users that I've made for samba access. I've locked their logins and redirected their shells to null, so I'm not worried about that, but are these outside attempts somehow finding my user names, or are they just brute-forcing commonly used ones? They are pretty common ones (accounting, sales, etc.).

Deny everyone and only allow only the valid IPs.
/etc/hosts.(allow|deny) are your friends.

# ? Aug 20, 2009 19:42

dont skimp on the shrimp: Apr 23, 2008

They're guessing. It's just a script. Either install fail2ban or just change the default port.

E: ^^ Or what he said.

# ? Aug 20, 2009 19:52

crazyfish: Sep 19, 2002

I checked the last 10 pages or so, so if this is a repeat question, I apologize.

What is the general state of ATI's Linux driver situation? I have a desktop at work with an fairly recent Nvidia card that Ubuntu found and installed the driver for with zero issues. However, I'm looking to build a new desktop machine soon for home that may be dual booting Ubuntu and Win7 (though Win7 only is more likely), and from the parts picking megathread, they basically stated that ATI cards are the best value for money at the moment. I'm no stranger to Linux and mucking about in random configs, but a turnkey solution like Ubuntu + Nvidia would be ideal.

# ? Aug 20, 2009 19:56

dont skimp on the shrimp: Apr 23, 2008

crazyfish posted:

I checked the last 10 pages or so, so if this is a repeat question, I apologize.

What is the general state of ATI's Linux driver situation? I have a desktop at work with an fairly recent Nvidia card that Ubuntu found and installed the driver for with zero issues. However, I'm looking to build a new desktop machine soon for home that may be dual booting Ubuntu and Win7 (though Win7 only is more likely), and from the parts picking megathread, they basically stated that ATI cards are the best value for money at the moment. I'm no stranger to Linux and mucking about in random configs, but a turnkey solution like Ubuntu + Nvidia would be ideal.

You really don't want to muck around with ATI. The current state is pretty horrible in my experience, though that's limited to a bit older cards (around R500 I think). If it works, then yeah everything will be fine and dandy, but if it doesn't you'll have hell even getting decent acceleration working.

# ? Aug 20, 2009 20:00

crazyfish: Sep 19, 2002

Zom Aur posted:

You really don't want to muck around with ATI. The current state is pretty horrible in my experience, though that's limited to a bit older cards (around R500 I think). If it works, then yeah everything will be fine and dandy, but if it doesn't you'll have hell even getting decent acceleration working.

Nvidia it is then. Thanks for your help.

# ? Aug 20, 2009 20:17

Postal: Aug 9, 2003; Don't make me go postal!

Zom Aur posted:

They're guessing. It's just a script. Either install fail2ban or just change the default port.

E: ^^ Or what he said.

fail2ban works well and allows you to keep addresses open for you to connect from other locations. If you have a small set of locations you access from just put those in your /etc/hosts.allow file and put sshd: ALL or ALL: ALL in your /etc/hosts.deny file

# ? Aug 20, 2009 20:39

BENGHAZI 2: Oct 13, 2007; by Cyrano4747

So I'm trying to run UNR on my acer aspire one

I downloaded the image, made a bootable USB, plugged it in, turned on the acer, and it booted into windows

What am I doing wrong here

# ? Aug 21, 2009 21:27

spiritual bypass: Feb 19, 2008; Grimey Drawer

Dickeye posted:

So I'm trying to run UNR on my acer aspire one

I downloaded the image, made a bootable USB, plugged it in, turned on the acer, and it booted into windows

What am I doing wrong here

Get into the BIOS configuration and see if you can enable booting from USB or switching USB to be the first boot choice.

# ? Aug 21, 2009 21:30

dont skimp on the shrimp: Apr 23, 2008

Dickeye posted:

So I'm trying to run UNR on my acer aspire one

I downloaded the image, made a bootable USB, plugged it in, turned on the acer, and it booted into windows

What am I doing wrong here

Hold F12, then select the USB-stick.

# ? Aug 21, 2009 21:54

BENGHAZI 2: Oct 13, 2007; by Cyrano4747

Alright I got that to work and I like it

I want to install it now

I'd also like to be able to dual boot, how do I set it up to do this instead of overwriting windows completely

Like I'm at the part where it's showing me my partitions and I have no idea what to click next

# ? Aug 21, 2009 22:02

dont skimp on the shrimp: Apr 23, 2008

Dickeye posted:

Alright I got that to work and I like it

I want to install it now

I'd also like to be able to dual boot, how do I set it up to do this instead of overwriting windows completely

Like I'm at the part where it's showing me my partitions and I have no idea what to click next

Resize the windows partition, create a new partition on the empty space, set that partition as /, don't create a swap partition at all. It won't make any changes until the last step of the installer I think, so just double check you've selected the right partition and it should be fine.

However, the drive might be a bit small. It's just 8 GB, and I'd recommend at least 2-3 GB for linux alone.

# ? Aug 21, 2009 22:19

BENGHAZI 2: Oct 13, 2007; by Cyrano4747

My drive is 150gigs duder

Also I mean how do I do that in the installer

I literally do not know how to do that because when I click the big partition (there's a 142g one and one that's 7g) I cannot resize anything (this is all in the installer still)

As it is I'm going to try partitioning on windows and then just installing to the premade partition

# ? Aug 21, 2009 22:23

dont skimp on the shrimp: Apr 23, 2008

Dickeye posted:

My drive is 150gigs duder

Also I mean how do I do that in the installer

I literally do not know how to do that because when I click the big partition (there's a 142g one and one that's 7g) I cannot resize anything (this is all in the installer still)

As it is I'm going to try partitioning on windows and then just installing to the premade partition

Okay, do that. Make two new partitions, one 2GB for swap and one 8GB for the system. Then select "partition manually" in the installer, select the 2GB partition, set the filesystem to swap and mountpoint to swap, then select the 8GB one, select ext4 or ext3 as filesystem and / as mountpoint.

Just be sure to doublecheck the layout so you haven't selected the windows partition or something.

# ? Aug 21, 2009 22:27

BENGHAZI 2: Oct 13, 2007; by Cyrano4747

Well Windows is being really weird now for some reason

So I may just be overwriting the whole thing and saying gently caress it

What programs can I use for word processing and such on Ubuntu that the files will be able to open on Windows on my desktop, just in case

# ? Aug 21, 2009 22:36

dont skimp on the shrimp: Apr 23, 2008

Openoffice or abiword can both save as .doc, .odf and .rtf so both should be usable. Openoffice also has a spreadsheet editor, but if you'd like something lighter you could try gnumeric.

Image editing can be done in GIMP, but if you want vector stuff you could give inkscape a shot.

If you need to gently caress around with audio files, there's audacity. Burning discs can be done in either k3b or brasero.

Anything else?

# ? Aug 21, 2009 22:42

BENGHAZI 2: Oct 13, 2007; by Cyrano4747

Nope that's it

I think that's going to be what I do here

And then maybe reinstall Windows as a partition when I get home at Christmas and get my old XP disc out

# ? Aug 21, 2009 22:51

BENGHAZI 2: Oct 13, 2007; by Cyrano4747

Wait I lied one more question

How do I open a terminal in unr

# ? Aug 21, 2009 23:54

dont skimp on the shrimp: Apr 23, 2008

Dickeye posted:

Wait I lied one more question

How do I open a terminal in unr

Should be on the launcher, I think?

Maybe under system or utilities or something.

Otherwise, I think you can open a run dialog with Alt+F2, then just type in gnome-terminal

# ? Aug 22, 2009 00:01

BENGHAZI 2: Oct 13, 2007; by Cyrano4747

Yeah I found it

Part 2 of that question: I installed comix using sudo apt-get install comix

Where will I find it now on my computer

# ? Aug 22, 2009 00:28

dont skimp on the shrimp: Apr 23, 2008

Dickeye posted:

Yeah I found it

Part 2 of that question: I installed comix using sudo apt-get install comix

Where will I find it now on my computer

The binary probably lies in /usr/bin/, the desktop launcher (what you see as an icon) probably lies in /usr/share/applications. If it's not on the launcher menu yet you probably just need to log out and log in again.

# ? Aug 22, 2009 00:53

BENGHAZI 2: Oct 13, 2007; by Cyrano4747

Stuff's arranged a little differently in UNR but I ended up finding it

# ? Aug 22, 2009 02:38

spiritual bypass: Feb 19, 2008; Grimey Drawer

Dickeye posted:

Stuff's arranged a little differently in UNR but I ended up finding it

There's a setting somewhere that allows you to switch to the normal GUI, which I really prefer on my eee900. On my computer, it's much faster and makes more sense.

# ? Aug 22, 2009 04:02

BENGHAZI 2: Oct 13, 2007; by Cyrano4747

See I actually really like the way UNR is set up. On the small screen it's a lot less cluttered and a lot easier to find things

# ? Aug 22, 2009 13:25

maskenfreiheit: Dec 30, 2004

Edit: Double Post

maskenfreiheit fucked around with this message at 20:55 on Mar 13, 2017

# ? Aug 22, 2009 19:39

other people: Jun 27, 2004; Associate Christ

I may have posted this here before, but I am becoming desperate! I switched from gentoo to xubuntu for ease of use, but it has resulted in my system only using a single core of my quad core cpu! What the gently caress ubuntu? I am seriously considering installing gentoo again, but I would like to avoid it if at all possible.

I have a Core 2 Quad Q6600 cpu on an Asus P5K SE (Intel P35 chipset) motherboard. I have xubuntu 9.04 installed, and the kernel right now is 2.6.28-15-generic #49-Ubuntu SMP Tue Aug 18 19:25:34 UTC 2009 x86_64.

Everything that reports cpu info is only reporting a single cpu/core. I have an error when I boot saying "Local APIC #0 not detected. Using dummy local APIC instead." If I try to remove the noapic and nolapic lines from my grub boot string the computer locks up while ubuntu is loading.

I had gentoo linux installed on this computer for years and smp/apic worked fine. What can I do to solve this problem with ubuntu?

I believe SMP is not working because apic is not on, but I cannot confirm that.

root@gohan:/home/patrick# cat /proc/cpuinfo
processor : 0
vendor_id : GenuineIntel
cpu family : 6
model : 15
model name : Intel(R) Core(TM)2 Quad CPU Q6600 @ 2.40GHz
stepping : 11
cpu MHz : 1596.000
cache size : 4096 KB
physical id : 0
siblings : 1
core id : 0
cpu cores : 1
apicid : 0
initial apicid : 0
fpu : yes
fpu_exception : yes
cpuid level : 10
wp : yes
flags : fpu vme de pse tsc msr pae mce cx8 sep mtrr pge mca cmov pat pse36 clflush dts acpi mmx fxsr sse sse2 ss ht tm pbe syscall nx lm constant_tsc arch_perfmon pebs bts rep_good pni dtes64 monitor ds_cpl vmx est tm2 ssse3 cx16 xtpr pdcm lahf_lm tpr_shadow vnmi flexpriority
bogomips : 4800.04
clflush size : 64
cache_alignment : 64
address sizes : 36 bits physical, 48 bits virtual
power management:

root@gohan:/home/patrick# mpstat -P ALL
Linux 2.6.28-14-generic (gohan) 08/06/2009 _x86_64_ (1 CPU)

12:41:26 AM CPU %usr %nice %sys %iowait %irq %soft %steal %guest %idle
12:41:26 AM all 13.95 0.36 2.55 6.68 0.06 0.03 0.00 0.00 76.36
12:41:26 AM 0 13.95 0.36 2.55 6.68 0.06 0.03 0.00 0.00 76.36

# ? Aug 24, 2009 01:40

dont skimp on the shrimp: Apr 23, 2008

How experienced are you with compiling your own kernels?

Since you ran gentoo, I suspect you have at least some experience. Try getting a newer kernel from kernel.org, then either copy your current config or just make your own. This should fix it, since it sounds like a kernel bug (either in config or in code) to me.

# ? Aug 24, 2009 13:57

other people: Jun 27, 2004; Associate Christ

Zom Aur posted:

How experienced are you with compiling your own kernels?

Since you ran gentoo, I suspect you have at least some experience. Try getting a newer kernel from kernel.org, then either copy your current config or just make your own. This should fix it, since it sounds like a kernel bug (either in config or in code) to me.

I was thinking of trying that. There are many different guides to making your own kernel under ubuntu, is there one that you can recommend? It seems to be a pretty convoluted process with ubuntu. Or can I just do a vanilla kernel build, like one uses with gentoo? I imagine ubuntu has their own patch set and I would never be able to setup all the modules correctly.

I still have the kernels/configs from my gentoo installs. Is there any convenient way to compare the configs of the two systems to maybe get an idea of where ubuntu is going wrong on my system?

# ? Aug 24, 2009 15:29

dont skimp on the shrimp: Apr 23, 2008

Kaluza-Klein posted:

I was thinking of trying that. There are many different guides to making your own kernel under ubuntu, is there one that you can recommend? It seems to be a pretty convoluted process with ubuntu. Or can I just do a vanilla kernel build, like one uses with gentoo? I imagine ubuntu has their own patch set and I would never be able to setup all the modules correctly.

I still have the kernels/configs from my gentoo installs. Is there any convenient way to compare the configs of the two systems to maybe get an idea of where ubuntu is going wrong on my system?

As long as you configure you kernel properly, there shouldn't be any problem unless ubuntu absolutely requires a certain patch. You should be able to use the configs from gentoo since it's the same machine. When you make menuconfig or oldconfig you should be prompted about newer features and such, then just make install and make modules-install I guess and configure grub to find the new kernel. I don't know how safe this is though, if it will overwrite your old ubuntu kernels. I don't think it will though.

# ? Aug 24, 2009 15:37

other people: Jun 27, 2004; Associate Christ

Zom Aur posted:

As long as you configure you kernel properly, there shouldn't be any problem unless ubuntu absolutely requires a certain patch. You should be able to use the configs from gentoo since it's the same machine. When you make menuconfig or oldconfig you should be prompted about newer features and such, then just make install and make modules-install I guess and configure grub to find the new kernel. I don't know how safe this is though, if it will overwrite your old ubuntu kernels. I don't think it will though.

Well, I have started following this: https://wiki.ubuntu.com/KernelTeam/GitKernelBuild
I think it will result in much the same thing, just a wee bit neater since it uses packages.

Even if I figure this out with a custom kernel, it means I will be building my own kernels indefinitely, eh? Why did I leave gentoo?

# ? Aug 24, 2009 15:40

JHVH-1: Jun 28, 2002

Kaluza-Klein posted:

Well, I have started following this: https://wiki.ubuntu.com/KernelTeam/GitKernelBuild
I think it will result in much the same thing, just a wee bit neater since it uses packages.

Even if I figure this out with a custom kernel, it means I will be building my own kernels indefinitely, eh? Why did I leave gentoo?

Have you checked if there are kernel package updates to what you are running already? What you are experiencing could have been a bug in that specific kernel package that was later fixed.

Otherwise how often do you need to upgrade kernels? Once everything is working theres not a whole lot of need to do it that often. You can always install multiple kernel packages too, thats the nice thing about it. They will exist side by side and you can boot into whatever one you want. If you run into a bad kernel you can remove it and put the last package you built back. It configures group and everything for you. Once you have a working kernel config for your machine you just do make oldconfig and rebuild with whatever updated source you get.

# ? Aug 24, 2009 15:50

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# ? May 10, 2024 14:45

maskenfreiheit: Dec 30, 2004

Edit: Double Post

maskenfreiheit fucked around with this message at 20:55 on Mar 13, 2017

# ? Aug 24, 2009 15:55

The Something Awful Forums > Discussion > Serious Hardware/Software Crap > The Linux Questions Thread: a bunch of pitfalls, but technically it's possible

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