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Sep 102018
 

If you have not heard, Steam have added a compatibility layer to Steam which allows a limited number of Windows games to run. The “compatibility layer” is in fact a fork of WINE called Proton.

Peered at from 500 metres away, Proton allows Windows software to run (or not infrequently crash and burn) by translating the Win32 API into Linux APIs, and translating the variety of graphics APIs into Vulkan. That is a really difficult thing to do.

I have taken a very quick look at the new Steam client (and “Proton” is no longer part of a beta release of the Steam client – it’s in the standard client). It works perfectly adequately, although you will have variable experiences running Windows software.

For some reason this news has captured the imagination of a number of ‘tubers who are more gamers than Linux users, which has lead to some misunderstanding :-

  1. This is not Linux gaming; it is Windows gaming under Linux. If you have a bad experience with Steam under Linux, you are not experiencing a bad time with Linux gaming. Linux gaming involves native Linux software, and yes there is some out there.
  2. Problems with Steam could well be down to the Proton compatibility layer with unsupported API calls or buggy usage of the Win32 API which relies on Windows behaving in a certain way for undefined parameters.
  3. In addition problems with Steam could be due to the hardware you are running; take a game that works perfectly fine with an Nvidia card. It may behave problematically with an AMD card or even a different Nvidia card. Or the other way around.

The important thing to remember when looking at videos about Steam is that the person looking at Steam may not be the most experienced Linux user out there. That is not necessarily bad – the whole purpose of Steam is to be able to run games easily without a whole lot of Linux experience.

But they may not be understanding properly what is going on – for example the first thing I would do as a professional game-orientated ‘tuber would be to try out a selection of games with an nvidia card, and then repeat using an AMD card – just to see if things work better, worse, or at least differently.

And again, this is not about Linux gaming but about allowing easy access to old Windows titles that someone may have bought in the past. 

Pentland Hills
Sep 082018
 

Having used Linux for well over 20 years (yes it is that old), and Unix before that, I’m often puzzled by how scary some people seem to find Linux. Why should it be scary? It’s just a computer – you’re the human in charge of it.

Yes There Are Gooeys

(graphical user interfaces – GUIs – gooeys)

Yes there is plenty of software with a graphical user interface – I use plenty on a daily basis including a standard web browser, an email client, a password manager, an office package.

On a slightly less frequent basis there are many more that I use. Indeed providing that you accept the use of alternatives, you can find Linux software to do just about anything.

But Don’t Ignore The Command-Line

Yes, Linux has a command-line, and for those of us familiar with it, it can be very powerful. And there is no harm in learning how to use the command-line just to the point where you can follow instructions on how to “get something done” there.

Because if I have a fix for some niggle that you are having, it is easier and less error-prone to pass instructions for a command-line incantation than instructions for a gooey (and yes I have done both).

The Birds

Jul 302018
 

Alternatively, why does Windows use drive letters? Because if you are coming from an old unix background, drive letters are just as weird as the lack of them if you are coming from a Windows background.

I mean, why is Windows installed on drive C? What ever happened to drives A and B?

Technically Linux does have the equivalent of drive letters but they are rarely used directly (unless you’re weird like I am). For example I currently have an SD card plugged into my desktop system, and it has the path /dev/disk/by-label/EOS_DIGITAL (or /dev/sdo1).

Historically, Unix (which is loosely the predecessor of Linux) ran on large minicomputers where system administrators would decide what disks were “mounted” where.  The Linux equivalent of drive C is effectively “/” (root), and you can attach (or “mount”) disks at any point underneath that – for example /home.

This allowed people to use an old Unix machine without worrying where this disks were; and allowed system administrators to add and remove disks as and where they were needed. These days we are all system administrators as well as users – that little voice you hear from time to time saying things like “When would be a good time to update the operating system?” and “I must clean up those temporary files all over the place” are your inner system administrator speaking up.

And if you don’t hear that inner voice, cultivate it!

With device paths, Linux has the opportunity to create sensible friendly names for disks, but a historical accident has resulted in almost every kind of disk being identified as a SCSI disk – SATA disks (a normal hard disk), SAS disks (server hard disks), Fiber Channel disks (SAN hard disks), and even USB storage devices all use SCSI commands.

So nearly all Linux disks are identified as /dev/sd followed by a letter (a “drive letter” – we can’t get away from them) and a number indicating the partition. Fortunately there is also the relatively new /dev/disks directory that has slightly friendlier names for disk devices. If you are getting into low-level disk management, learn these directories; in particular if you are looking into enterprise disk management look at WWNs (each disk has a unique “world-wide-number”).

Now back to Windows. Windows is the descendent of DOS, which goes back to the time when PCs may not have had hard disks and by default would have booted off a floppy disk in drive A with a data disk in drive B. Later PCs came with hard disks which used drive C on the assumption that you would have one or two floppy drives.

Windows has been updated over the years and there is a great deal of sophistication under the surface, but it does act a bit conservatively when it comes to drive letters – A and B are by default reserved for floppy drives even though I haven’t seen one of those on an ordinary system for years. You can use A and B for other purposes such as mapping network drives – A makes a good drive for a NAS drive.

If we get away from the terminology of “drive letters” and “device paths” and instead refer to them as “storage device names”, both Linux and Windows have “storage device names” but Linux prefers to hide that level of detail.

Personally I prefer the Linux way, but whatever floats your boat.

Feb 082018
 

Some time ago, I wrote about using new (for the time) partition tables to create a memory stick with 100 partitions; each with a mountable file system on. And decided the time was right to have another look to see if things have improved … or degraded. After all, things have moved on, and everything has been updated.

I also improved the creation script slightly :-

#!/bin/zsh

disk=/dev/sdb

parted $disk mklabel gpt
for x in {1..99}     
do
  echo Partition: $x
  parted -s $disk mkpart FAT $(($x * 100)) $((x * 100 + 99))
  sleep 0.2
  mkfs -t vfat -n DOOM${x} ${disk}${x} 
  sleep 0.2
done

And I used a zsh-ism – so shoot me.

The script ran fairly well, but :-

  1. The load average shot up through the roof as copies of systemd-udevd started, worked, and closed.
  2. Strangely the links in /dev/disk/by-label (and presumably elsewhere) kept disappearing and re-appearing. As if on each partition change to the disk, all of the disk’s devices were removed and re-created. This is probably not dangerous, but harmful to performance.
  3. Given that I used sleep within my script, it is hard to criticise performance, but it did seem slow. However this is not an area worth optimising for.
  4. Unlike last time, Linux did not refuse to create any file systems.

Now onto trying to stick the memory stick of doom into various systems…

Ubuntu 17.10

This was of course the machine I ran the script on initially.

This did not go so well, with the machine initially freezing momentarily (although it is a cheap and nasty laptop), apparently silently refusing to mount half the file systems, and “Files” (or Nautilus) getting wedged at 100% processor usage.

After some 10 minutes, Nautilus was still stuck with no signs of making any progress.

After I lost patience and restarted “Files”, it came up okay showing the mounted file systems and showing the file systems it had failed to mount. On one occasion the additional file systems were shown as unmounted (and could be mounted) and on another they were shown as mounted (even though they weren’t).

So both “Files” gets a thumb down for getting stuck, and whatever else gets a thumb down for trying and failing (silently) to mount all the file systems.

This is definitely a serious degradation from the previous try, although probably GNOME-specific rather than Linux-specific. Especially as a later mounted all the file systems from the command-line on a different system without an issue.

Windows 10

Windows 10 became unusually sluggish, although it may have been in the mysterious “we’ll run Windows update at the most inconvenient time possible” mode. It did attempt to mount the file systems, and failed miserably – it mounted the first set until it ran out of drive letters.

Which is just about understandable, as there aren’t 100 drive letters. However :-

  1. Where was the message saying “There are 100 partitions in this silly USB stick. You can see the first 22; additional ones can be mounted within folders if there is important data on them.”.
  2. Why is Windows still limiting itself with single letter device names? Okay it is what we’re used to, but when you run out of drive letters, start using the file system label – “DOOM99:”. Hell, I’d like all my removable disks treated that way under Windows.

As for the whole “ran out of drive letters, so don’t bother with the rest”, how many people are aware that drives can be mounted (as Unix does) in directories?

macOS 10.13 (OSX)

Oddly enough (but perhaps sensibly), macOS refused to have anything to do with the memory stick. Indeed it popped up a dialog suggesting initialising the disk, which is perhaps not particularly sensible with a disk that could contain data.

The “Disk Utility” happily showed the disk – increasing the size of the window inconveniently wide in the process – and happily indicated 99 partitions.

At the Terminal prompt, it was apparent that the operating system had created device files for each of the partitions, but for some reason wouldn’t mount them.

Summary

Inserting a “stick of doom” with 100 partitions on it into any machine is still a risky thing to do. It’s also a dumb thing to do, but something operating system developers should be doing.

Linux (or rather GNOME) performs significant worse this time around than previously, and my suspicions are that systemd is to blame.

But however bad Linux does, none of the operating systems actually do sensible things with the “stick of doom”. macOS arguably comes closest with refusing to have anything to do with the disk, but it also encourages you to reformat the disk without saying that it could be erasing data.

Ideally, a gooey would pop up a window listing the file system labels and ask you which you want to mount. That’s not even a bad idea for a more sensibly set up memory stick.

Pebble On Steel

Aug 272017
 

Every so often, somebody (or organisation) proclaims that this year is the year of Linux on the desktop. Given the number of times this has occurred, you would have thought that the Cassandras of the Linux world would stop trying to predict it. In fact I am not entirely sure what it is supposed to be – everyone using Linux on the desktop, or just some? And if it is just some people, how many?

It is essentially nonsense – if you use Linux on the desktop, every year is the year of Linux on the desktop; and if you do not, it isn’t.

Assuming you are someone who has more than two brain cells to rub together and are prepared to do some learning, it is perfectly possible to run Linux on the desktop. You can do pretty much everything with Linux that you can do with Windows. In fact the one area that Linux is traditionally weak – upgrading firmware of third party devices (such as media players, wireless mice – is beginning to change with LVMS and fwupd.

To give an example, I was recently upgrading some Logitech wireless mice to eliminate a serious security flaw, and I tried with Windows, OSX, and finally Linux. Both the Windows and OSX methods failed, whereas the Linux method just worked.

In fact even if the Windows method had worked, it would have been a lot more complex. I had to download the Logitech software (admittedly this step would probably be unnecessary if I was used to using the wireless mouse under Windows), know that a firmware upgrade was necessary, download the firmware upgrade, and finally load it into the upgrade tool.

Under Linux? Assuming I had been using some gooey tool like GNOME Software, it would have notified me that an upgrade was available and after a request would have upgraded it for me. I (of course) chose to do it the geeky way from the command-line, but even so running :-

# fwupmgr refresh
# fwupmgr update

… is a great deal simpler than the Windows way. And that is before you consider that with Windows, you need to download a firmware update tool for every device whereas the Linux way it is just one tool.

Of course in practice, the Linux method only works for a handful of devices – of the innumerable Linux machines I run only one has available updates for the desktop computer’s firmware (the Dell at work), and of the peripheral (or not so peripheral) devices only a tiny handful can be upgraded today.

But it is not inconceivable that in the not too distant future, the sensible way to upgrade the firmware of various devices will be to install Linux, and let it do it for you. Particularly if device manufacturers realise that by adopting Linux as the firmware upgrade delivery method, they can save time and effort.

“But I know Windows” – actually you know Windows 7, or Windows XP, or Windows 10; each of which is very different from each other. And whilst Linux has even more variability at first glance, there is actually more commonality between different versions of Linux. Or in other words, the effort of learning Linux in the first place is rewarded by less of a need to completely re-educate yourself every time you upgrade.

This is not intended as encouragement for you to switch to Linux (although if you are involved in IT you should at least be familiar with Linux), but intended as a criticism of the concept of a year of the Linux desktop. It isn’t useful, and what is worse it leads to the false impression of failure – if everyone is not using Linux on the desktop, then Linux has failed.

Linux on the desktop has not failed because I use it on the desktop.

Mar 182017
 

The TiPro programmable keyboards are quite fun for those who are into their keyboards, but with one big problem: the programming tool is Windows only. Well at least if you happen to have a USB-based TiPro; otherwise you need to set up the serial interface as the PS/2 interface is only usable for programming with a 32-bit Windows.

As it turns out, if you try to run it under a virtual machine and assign the USB device of the keyboard to the virtual machine, it still fails – somehow it doesn’t like staying assigned to the virtual machine. However there is a fix for this – using the command-line VirtualBox tools to set up a permanent USB filter.

To assign, first of all determine the name of your virtual machine with :-

VboxManage list vms

Next, add a USB filter – you can normally assign it to “slot” (or index) 1, but you may have to check what slots are available if you already do this :-

VBoxManage usbfilter add 1 --target "W10" --name TiPro --vendorid 0x1222 --productid 0xfaca

Once that is done, the Windows tool should be able to find the keyboard to start programming it. If necessary, reboot the virtual machine or try assigning the USB device via the menu option.

During programming it is helpful to remember than raw USB HID codes can be used by right-clicking in the input field for a key, selecting “Text Input” and inputing the code in the form “/${hex hid code} ${hex hid code}\” – such as “/69 69\” (a list can be found at: http://www.usb.org/developers/hidpage/Hut1_12v2.pdf)

Removal at the end:

VBoxManage usbfilter remove 1 --target "W10"

After the removal it seems that disconnecting and reconnecting the device is necessary for Linux to pick it up (or possibly a udevadm trigger).

b

Sep 012016
 

One of the advantages that ZFS brings, is that it is so easy to create file systems, that you can create them for purposes that you would not previously do. For example, I have an additional file system mounted under my home directory for a certain application that generates a lot of data that I do not need backed up. Because the script I use to back up stuff does not cross file system boundaries (i.e. it does not descend into a directory that contains a mounted file system), I can simply exclude a large amount of frequently changing data by making a file system.

Or I might (as it happens I do not, but I could well do) create file systems for large lumps of data to easily see how much space they occupy – perhaps ~/Pictures. You can run a command like du -sh ~/Pictures, but that is an expensive command (it takes a while) and it tells you how large the files are; not how much space they occupy on disk. And on-disk compression can make that a significant difference! So simply run df -h ~/Pictures if that directory is on a separate file system.

But there is a bit of a gotcha with that. If you create such file systems in the normal way (such as zfs create pool/mikes-pictures; zfs set mountpoint=/home/mike/Pictures pool/mikes-pictures) you risk creating a situation that may prevent your home directory from mounting. If the “child” file system is mounted before the parent, it will not be possible for the parent file system to be mounted when booting.

Instead create the hierarchy properly :-

zfs create pool/h2
mkdir /h2
zfs set mountpoint=/h2 pool/h2
zfs create pool/h2/mike
zfs create pool/h2/mike/Pictures
ls /h2/mike/Pictures

You will also have to fix the permissions, but this is a far safer way of organising things suitable for future file system creation.

damascus-unix-prompt

Aug 292016
 

It seems that occasionally GNOME can go a little screwy and its fancy mouse pointer plugin can result in an invisible mouse pointer. Which makes doing anything just a little bit tricky.

If you can open a terminal, enter the command :-

gsettings set org.gnome.settings-daemon.plugins.cursor active false

And all should be well. At least until it decides to turn itself back on again (so make a note of this fix!).

damascus-unix-prompt

Dec 102015
 

damascus-unix-prompt

You have a a column of numbers that you have produced in some manner such as :-

$ awk '/clean message/ {print $(NF-1)}' mail.info.log
...
100935
12197
3606
84653
4498
99110
4762
3001
10889
12611
12249
12245
136599
49097
6668

And you want a quick and dirty way of finding the largest number. Well there is a way but it is perhaps the least efficient way to do it, and that is to sort the numbers into numerical order and use “head” to display the first one :-

$ awk '/clean message/ {print $(NF-1)}' mail.info.log | sort -rn | head -1
5476168

But frankly there must be a better method. And yes there is if you happen to be using zsh (or possibly others, but this has been tested with zsh). Simply iterate over the values assigning the current value to the “max” variable if the current variable is larger :-

$ max=0; for x in $(awk '/clean message/ {print $(NF-1)}' mail.info.log); [[ $x -gt $max ]] && max=$x; echo $max
5476168

You may be wondering why I don’t simply use the ability of awk to perform calculations. Well that is certainly possible, but I may not always be using awk to produce the numbers in the first place, and this is supposed to be a generic recipe.

Oct 232015
 

Have you ever wondered if you can tinker with the ps command to change how and what is displayed? No? Well give up reading this post then.

I've known about ps for ages and also the way that the output can be tinkered with, but have not had an excuse to dig into it properly until I was looking for a way for ps to show the Linux container name for each process (don't get excited: ps -o machine is documented but not implemented at the time of writing). 

If you read the manual page for ps you will be quickly distracted by all the different options available. These can be grossly simplified into three different groups of options: which processes to list, what to output, and how to sort the output.

Which Processes?

This can be simplified down to almost nothing; ps on it's own lists just the processes running from the current terminal (window) :-

% ps
  PID TTY          TIME CMD
 2591 pts/17   00:00:00 zsh
13325 pts/17   00:00:00 ps

If you want to display all processes, add the "-e" option :-

% ps -e
  PID TTY          TIME CMD
    1 ?        00:00:03 systemd
    2 ?        00:00:00 kthreadd
    3 ?        00:00:00 ksoftirqd/0
    5 ?        00:00:00 kworker/0:0H
    7 ?        00:00:54 rcu_sched
    8 ?        00:00:00 rcu_bh
    9 ?        00:00:35 rcuos/0
   10 ?        00:00:00 rcuob/0
   11 ?        00:00:00 migration/0
   12 ?        00:00:00 watchdog/0
(cut)

And lastly (not literally – there are other options), add the "-p" option to list processes by process ID :-

% ps -p 1
  PID TTY          TIME CMD
    1 ?        00:00:03 systemd

Tuning The Output

By default the fields that ps outputs is somewhat peculiar until you realise that the output fields have been frozen in time. The default choice is somewhat minimal; and I'm not in favour of minimalism. And what use is the TTY and the TIME fields?

The TTY field shows you what terminal the process is running on – this was handy on a multi-user system where you could find out who was on what terminal and then write a message directly to their screen. A great way of winding people up, but not so much use these days. And TIME? We're no longer billed for the cpu time we consume, so the time spent running on the cpu is a rather pointless thing to list.

The "-f" option displays more information :-

% ps -f
UID        PID  PPID  C STIME TTY          TIME CMD
mike     26486 31092  0 21:24 pts/24   00:00:00 ps -f
mike     31092 31091  0 20:11 pts/24   00:00:00 -zsh

But the output is still somewhat peculiar, and there are other more interesting fields to display.

There are various options for choosing the output format amongst a set of predefined choices, but the best bet is to ignore these and jump straight into selecting the individual fields that you want. These can be found in the manual page in the "STANDARD FORMAT SPECIFIERS" section. Simply list the fields you want after the "-o" option :-

% ps -o pid,comm,pcpu,pmem,nlwp,user,stat,sgi_p,wchan,class,pri,nice,flags
  PID COMMAND         %CPU %MEM NLWP USER     STAT P WCHAN  CLS PRI  NI F
28061 ps               0.0  0.0    1 mike     R+   3 -      TS   19   0 0
31092 zsh              0.0  0.0    1 mike     Ss   * -      TS   19   0 0

Obviously typing this in every time is somewhat less than ideal, but fortunately the authors of ps have already thought of this. By listing the fields within the PS_FORMAT environment variable, there is no need to specify -o :-

% export PS_FORMAT="pid,comm,pcpu,pmem,nlwp,user,stat,sgi_p,wchan,class,pri,nice,flags"
% ps
  PID COMMAND         %CPU %MEM NLWP USER     STAT P WCHAN  CLS PRI  NI F
29440 ps               0.0  0.0    1 mike     R+   5 -      TS   19   0 0
31092 zsh              0.0  0.0    1 mike     Ss   * -      TS   19   0 0

To make this pernament, add this to your shell startup rc file; whilst editing you may as well set PS_PERSONALITY to "linux".

Sorting The Output

According to the ps documentation, by default the output is not sorted. In that case either my kernel's process table is remarkably well organised, or the distributions I use "cheat" and sort the output in process ID order. In the distant past where computers were shared amongst too many people, and the machines themselves were quite slow, it made sense for the output of ps to be unsorted. But it certainly doesn't make sense now.

And the ps command allows processes to be sorted by any field that you can specify in the "STANDARD FORMAT SPECIFIERS" section which conveniently enough you are now intimately acquianted. Simply add the relevant field to the –sort option :-

% ps --sort pcpu
  PID COMMAND         %CPU %MEM NLWP USER     STAT P WCHAN  CLS PRI  NI F
31092 zsh              0.0  0.0    1 mike     Ss   * -      TS   19   0 0
31743 ps               0.0  0.0    1 mike     R+   5 -      TS   19   0 0

With just a short list (and such a low percentage of the cpu in use) it doesn't make sense, but added to -e, it does.

Rather than change the default sort order, I personally prefer to configure aliases to do the job for me :-

% alias pscpu='ps --sort pcpu'
% alias psmem='ps --sort pmem'

Preferring to use an alias here is rather convenient as there doesn't seem to be a way to configure the default sort order – officially there isn't one!

Reading through the ps manual page (during which you will notice many different options referring to old Unix varients) is a reminder of just how long and bitter the fight over which ps varient was the best. And now for a completely irrelevant picture :-

damascus-unix-prompt

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