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For a while I’ve had my monitoring systems alert me via XMPP (Jabber). To do that I used the sendxmpp command-line program which worked well for it’s basic tasks. I recently noticed that my laptop and workstation which I had upgraded to Debian/Testing weren’t sending messages, I’m not sure when it started as my main monitoring of such machines is to touch a key and see if there’s a response – if I’m not at the keyboard then a failure doesn’t bother me too much.
I’ve filed Debian bug #1032868 [1] about this. As sendxmpp is apparently not supported upstream and we are preparing for a release it could be that the next version of Debian is released without this working (if it’s specific to talking to Prosody) or without sendxmpp (if it fails on all Jabber servers).
I next tested xmppc which doesn’t send messages (gives no error when I have apparently correct parameters and just doesn’t send anything) and doesn’t display any text output for info related commands while not giving error messages or an error return code. I filed Debian bug #1032869 [2] about this.
Currently the only success I’ve found with Debian/Testing for this is with go-sendxmpp. To configure that you setup a file named ~/.config/go-sendxmpp/config with the following contents:
username: JABBER-ID
password: PASSWORD
Go-sendxmpp can take a username and password on the command-line but that’s bad for security as in the absence of SE Linux or other advanced security systems the password can be seen by any user on the same system who runs ps. To send a message run “echo $MESSAGE | go-sendxmpp $ADDR” to send $MESSAGE to $ADDR. It also has the option “go-sendxmpp -l” to listen for incoming messages. I don’t have an immediate need to receive messages from the command-line but it’s handy to have the option.
I probably won’t be able to get a new version of etbemon in Debian for the Bookworm release. So to get go-sendxmpp to work with etbemon you need to edit /usr/lib/mon/alert.d/mailxmpp.alert and change this sendxmpp line to this go-sendxmpp line:
open (XMPP, "| /usr/bin/sendxmpp -a /etc/ssl/certs -t @xmpprec -r $host") ||
open (XMPP, "| /usr/bin/go-sendxmpp @xmpprec") ||
I just did some quick tests of hyper-threading on my new E5-2696v3 CPU. I compiled the Linux 6.0.10 kernel with and without hyper-threading enabled. Here’s the times for “make -j36 bzImage” and “make -j36 modules” with HT enabled:
real 2m26.540s
user 55m25.121s
sys 9m56.443s
real 10m57.374s
user 309m21.531s
sys 58m1.070s
Here’s the times for “make -j18 bzImage” and “make -j18 modules” with HT disabled:
real 2m40.501s
user 31m35.295s
sys 5m43.523s
real 11m39.313s
user 170m46.840s
sys 31m37.756s
That’s 9.6% faster for bzImage and 6.4% faster for modules.
So for a performance boost that’s between 5% and 10% I get greater exposure to kernel security issues and more difficulty tracking CPU time. That doesn’t seem like a good trade-off so I’ve put the “nosmt” kernel command-line option back.
Vox has an insightful interview with the author of “Slouching Towards Utopia: An Economic History of the Twentieth Century” [1]. The main claim of that book is that “The 140 years from 1870 to 2010 of the long twentieth century were, I strongly believe, the most consequential years of all humanity’s centuries”. A claim that seems well supported.
PostMarketOS is an interesting OS for hardware designed for Android [2]. It is based on Alpine Linux, is small, and modular. If you want to change something just change that package not the entire image. Also an aim is to have as much commonality between devices as possible, all phones with the same CPU family can run the same packages apart from the kernel and maybe some utilities related to hardware. Abhijithpa blogged about getting started with pmOS, it seems easy to do [3].
Interesting article about gay samurai [4]. Regarding sex with men or women “an elderly arbiter, after hearing the impassioned arguments of the two sides, counsels that the wisest course is to follow both paths in moderation, thereby helping to prevent overindulgence in either”. Wow.
The SCP project is an interesting collaborative SciFi/horror fiction project [5] based on an organisation that aims to Secure and Contain dangerous objects and beings and Protect the world from them. The series of stories about the Anti-Memetics Division [6] is a good place to start reading.
I just got a E5-2696 v3 CPU for my ML110 Gen9 home workstation, this has a Passmark score of 23326 which is almost 3 times faster than the E5-2620 v4 which rated 9224. Previously it took over 40 minutes real time to compile a 6.10 kernel that was based on the Debian kernel configuration, now it takes 14 minutes of real time, 202 minutes of user time, and 37 minutes of system CPU time. That’s a definite benefit of having a faster CPU, I don’t often compile kernels but when I do I don’t want to wait 40+ minutes for a result. I also expanded the system from 96G of RAM to 128G, most of the time I don’t need so much RAM but it’s better to have too much than too little, particularly as my friend got me a good deal on RAM. The extra RAM might have helped improve performance too, going from 6/8 DIMM slots full to 8/8 might help the CPU balance access.
That series of HP machines has a plastic mounting bracket for the CPU, see this video about the HP Proliant Smart Socket for details [1]. I was working on this with a friend who has the same model of HP server as I do, after buying myself a system I was so happy with it that I bought another the same when I saw it going for a good price and then sold it to my friend when I realised that I had too many tower servers at home. It turns out that getting the same model of computer as a friend is a really good strategy so then you can work together to solve problems with it. My friend’s first idea was to try and buy new clips for the new CPUs (which would have delayed things and cost more money), but Reddit and some blog posts suggested that you can just skip the smart-socket guide clip and when the chip was resting in the socket it felt secure as the protrusions on the sides of the socket fit firmly enough into the notches in the CPU to prevent it moving far enough to short a connection. Testing on 2 systems showed that you don’t need the clip. As an aside it would be nice if Intel made every CPU that fits a particular socket have the same physical dimensions so clips and heatsinks can work well on all CPUs.
The TDP of the new CPU is 145W and the old one was 85W. One would hope that in a server class system that wouldn’t make a lot of difference but unfortunately the difference was significant. Previously I could have the system running 7/8 cores with BOINC 24*7 and I wouldn’t notice the fans being louder. It is possible that 100% CPU use on a hot day might make the fans sound louder if I didn’t have an air-conditioner on that was loud enough to drown them out, but the noteworthy fact is that with the previous CPU the system fans were a minor annoyance. Now if I have 16 cores running BOINC it’s quite loud, the sort of noise that makes most people avoid using tower servers as workstations! I’ve found that if I limit it to 4 or 5 cores then the system is about as quiet as it was before. As a rough approximation I can use as much CPU power as before without making the fans louder but if I use more CPU power than was previously available it gets noisy.
I also got some new NVMe devices, I was previously using 2*Crucial 1TB P1 NVMes in a BTRFS RAID-1 and now I have 2*Crucial 1TB P3 NVMes (where P1 is the slowest Crucial offering, P3 is better and more expensive, P5 is even better, etc). When doing the BTRFS migrations to move my workstation to new NVMe devices and my server to the old NVMe devices I found that the P3 series seem to have a limit of about 70MB/s for sustained random writes and the P1 series is about 35MB/s. Apparently with the cheaper NVMe devices they slow down if you do lots of random writes, pity that all the review articles talking about GB/s speeds don’t mention this. To see how bad reviews are Google some reviews of these SSDs, you will find a couple of comment threads on places like Reddit of them slowing down with lots of writes and lots of review articles on well known sites that don’t mention it. Generally I’d recommend not upgrading from P1 to P3 NVMe devices, the benefit isn’t enough to cover the effort. For every capacity of NVMe devices the most expensive devices cost more than twice as much as the cheapest devices, and sometimes it will be worth the money. Getting the most expensive device won’t guarantee great performance but getting cheap devices will guarantee that it’s slow.
It seems that CPU development isn’t progressing as well as it used to, the CPU I just bought was released in 2015 and scored 23,343 according to Passmark [2]. The most expensive Intel CPU on offer at my local computer store is the i9-13900K which was released this year and scores 62,914 [3]. One might say that CPUs designed for servers are different from ones designed for desktop PCs, but the i9 in question has a “TDP Up” of 253W which is too big for the PSU I have! According to the HP web site the new ML110 Gen10 servers aren’t sold with a CPU as fast as the E5-2696 v3! In the period from 1988 to about 2015 every year there were new CPUs with new capabilities that were worth an upgrade. Now for the last 8 years or so there hasn’t been much improvement at all. Buy a new PC for better USB ports or something not for a faster CPU!
In response to a post about my latest laptop I had someone ask why I chose an Intel CPU. I’ve been a fan of the Thinkpad series of laptops since the 90s. They have always seemed well constructed (given the constraints of being light etc) and had a good feature set. Also I really like the TrackPoint. I’ve been a fan of the smaller Thinkpads since I got an X-301 from e-waste [1] and the X1-Carbon series is the latest and greatest line of small Thinkpads.
AMD makes some nice laptop CPUs which appear to have low power use and good performance particularly for smaller numbers of threads, it seems that generally AMD CPUs are designed for fewer cores with higher performance per core which is good for laptops. But Lenovo only makes the Thinkpad Carbon X1 series with Intel CPUs so choosing that model of laptop means choosing Intel. It could be that for some combination of size, TDP, speed, etc Intel just happens to beat AMD for all the times when Lenovo was designing a new motherboard for the Carbon X1. But it seems more likely that Intel has been lobbying Lenovo for this. It would be nice if there was an anti-trust investigation into Intel, everyone who’s involved in the computer industry knows of some of the anti-competitive things that they have done.
Also it would be nice if Lenovo started shipping laptops with ARM CPUs across their entire range. But for the moment I guess I have to keep buying laptops with Intel CPUs.
The Dell T320
Almost 2 years ago I made a Dell PowerEdge T320 my home server [1]. It was a decent upgrade from the PowerEdge T110 II that I had used previously. One benefit of that system was that I needed more RAM and the PowerEdge T1xx series use unbuffered ECC RAM which is unreasonably expensive as well as the DIMMs tending to be smaller (no Load Reduced DIMMS) and only having 4 slots. As I had bought two T320s I put all the RAM in a single server getting a total of 96G and then put some cheap DIMMs in the other one and sold it with 48G.
The T320 has all the server reliability features including hot-swap redundant PSUs and hot-swap hard drives. One thing it doesn’t have redundancy on is the motherboard management system known as iDRAC. 3 days ago my suburb had a power outage and when power came back on the T320 gave an error message about a failure to initialise the iDRAC and put all the fans on maximum speed, which is extremely loud. When a T320 is running in a room that’s not particularly hot and it doesn’t have SAS disks it’s a very quiet server, one of the quietest I’ve ever owned. When it goes into emergency cooling mode due to iDRAC failure it’s loud enough to be heard from the other end of the house with doors closed in between.
Googling this failure gave a few possible answers. One was for some combinations of booting with the iDRAC button held down, turning off for a while and booting with the iDRAC button held down, etc (this didn’t work). One was for putting a iDRAC firmware file on the SD card so iDRAC could automatically load it (which I tested even though I didn’t have the flashing LED which indicates that it is likely to work, but it didn’t do anything). The last was to enable serial console and configure the iDRAC to load new firmware via TFTP, I didn’t get a iDRAC message from the serial console just the regular BIOS stuff.
So it looks like I’ll have to sell the T320 for parts or find someone who wants to run it in it’s current form. Currently to boot it I have to press F1 a few times to bypass BIOS messages (someone on the Internet reported making a device to key-jam F1). Then when it boots it’s unreasonably loud, but apparently if you are really keen you can buy fans that have temperature sensors to control their own speed and bypass the motherboard control.
I’d appreciate any advice on how to get this going. At this stage I’m not going to go back to it but if I can get it working properly I can sell it for a decent price.
The HP Z640
I’ve replaced the T320 with a HP Z640 workstation with 32G of RAM which I had recently bought to play with Stable Diffusion. There were hundreds of Z640 workstations with NVidia Quadro M6000 GPUs going on eBay for under $400 each, it looked like a company that did a lot of ML work had either gone bankrupt or upgraded all their employees systems. The price for the systems was surprisingly cheap, at regular eBay prices it seems that the GPU and the RAM go for about the same price as the system. It turned out that Stable Diffusion didn’t like the video card in my setup for unknown reasons but also that the E5-1650v3 CPU could render an image in 15 minutes which is fast enough to test it out but not fast enough for serious use. I had been planning to blog about that.
When I bought the T320 server the DDR3 Registered ECC RAM it uses cost about $100 for 8*8G DIMMs, with 16G DIMMs being much more expensive. Now the DDR4 Registered ECC RAM used by my Z640 goes for about $120 for 2*16G DIMMs. In the near future I’ll upgrade that system to 64G of RAM. It’s disappointing that the Z640 only has 4 DIMM sockets per CPU so if you get a single-CPU version (as I did) and don’t get the really expensive Load Reduced RAM then you are limited to 64G. So the supposed capacity benefit of going from DDR3 to DDR4 doesn’t seem to apply to this upgrade.
The Z640 I got has 4 bays for hot-swap SAS/SATA 2.5″ SSD/HDDs and 2 internal bays for 3.5″ hard drives. The T320 has 8*3.5″ hot swap bays and I had 3 hard drives in them in a BTRFS RAID-10 configuration. Currently I’ve got one hard drive attached via USB but that’s obviously not a long-term solution. The 3 hard drives are 4TB, they have worked since 4TB was a good size. I have a spare 8TB disk so I could buy a second ($179 for a shingle HDD) to make a 8TB RAID-1 array. The other option is to pay $369 for a 4TB SSD (or $389 for a 4TB NVMe + $10 for the PCIe card) to keep the 3 device RAID-10. As tempting as 4TB SSDs are I’ll probably get a cheap 8TB disk which will take capacity from 6TB to 8TB and I could use some extra 4TB disks for backups.
I haven’t played with the AMT/MEBX features on this system, I presume that they will work the same way as AMT/MEBX on the HP Z420 I’ve used previously [2].
Update:
HP has free updates for the BIOS etc available here [3]. Unfortunately it seems to require loading a kernel module supplied by HP to do this. This is a bad thing, kernel code that isn’t in the mainline kernel is either of poor quality or isn’t licensed correctly.
I had to change my monitoring system to alert on temperatures over 100% of the “high” range while on the T320 I had it set at 95% of “high” and never got warnings. This is disappointing, enterprise class gear running in a reasonably cool environment (ambient temperature of about 22C) should be able to run all CPU cores at full performance without hitting 95% of the “high” temperature level.
We are getting towards the freeze for Debian/Bookworm so the current state of packages isn’t going to change much before the release. Bugs will get fixed but missing features will mostly be missing until the next release.
Anarcat wrote an excellent blog post about using Wayland with the Sway window manager [1]. It seems pretty good if you like Sway, but I like KDE and plan to continue using it. Several of the important utility programs referenced by Anarcat won’t run with KDE/Wayland and give errors such as “Compositor doesn’t support wlr-output-management-unstable-v1”. One noteworthy thing about Wayland is the the Window manager and the equivalent to the X server are the same program so KDE has different Wayland code than Sway and doesn’t support some features. The lack of these features limits my ability to manage multiple displays and therefore makes KDE/Wayland unsuitable for many laptop uses. My work laptop runs Ubuntu 22.04 with KDE and wouldn’t correctly display on the pair of monitors on a USB-C dock that’s the standard desktop configuration where I work.
In my previous post about Wayland [2] I wrote about converting 2 of my systems to Wayland. Since then I had changed them back to X because of problems with supporting strange monitor configurations on laptops and also due to the KDE window manager crashing occasionally which terminates the session in Wayland but merely requires restarting the window manager in X. More recently I had a problem with the GPU in my main workstation sometimes not being recognised by the system (reporting no PCIe device), when I got a new one I couldn’t get X to work with the error “Cannot run in framebuffer mode. Please specify busIDs for all framebuffer devices” so I tried Wayland again. Now in the later stage of the Bookworm development process it seems that the problem with the KDE window manager crashing has been solved or mitigates and there is a new problem of the plasmashell process crashing. As I can restart plasmashell without logging out that’s much less annoying. So now my main workstation is running on Wayland with a slower GPU than I previously had while also giving a faster user experience so Wayland is providing a definite performance benefit.
Maybe for Trixie (the next release of Debian after Bookworm) we should have a release goal of having full Wayland support in all the major GUI systems.
The Intercept has an amusing and interesting article about senior Facebook employees testifying that they don’t know where Facebook stores all it’s data on users [1]. One lesson all programmers can learn from this is to document all these things in an orderly manner.
Cory Doctorow wrote a short informative article about inflation from a modern monetary theory perspective [2].
Russ Allbery wrote an insightful blog post about effecive altruism and respect for disadvantaged people [3]. GiveDirectly sounds good.
The Conversation has an interesting article about the Google and Apple app stores providing different versions of apps for users in different regions [4]. Apparently there are specific versions to comply with GDPR and versions that differ in adverts. The hope that GDPR would affect enough people to become essentially a world-wide standard was apparently overly optimistic. We need political lobbying in all countries for laws like the GDPR to force the app stores to give us the better versions of apps.
Arya Voronova wrote an informative article about USB-C and extension or data blocker cables [5]. USB just keeps getting more horrible in technology while getting more useful in functionality. Laptops and phones catching fire will probably become more common in future.
John McBride wrote an insightful article about the problems in the security of the software supply chain [6]. His main suggestion for addressing problems is “If you are on a team that relies on some piece of open source software, allocate real engineering time to contributing”, the problem with this is that real engineering time means real money and companies don’t want to do that. Maybe having companies contribute moderate amounts of money to a foundation that hires people would be a viable option.
Toms Guide has an interesting article describing problems with the Tesla [7]. It doesn’t cover things like autopilot driving over children and bikers but instead covers issues of the user interface that make it less pleasant to drive and also remove concentration from the road.
The BBC has an interesting article about the way mathematical skill is correlated with the way language is used to express numbers [8]. Every country with a lesser way of expressing numbers should switch to some variation of the East-Asian way.
Science 2.0 has an interesting blog post about the JP Aerospace plans to use airships to get most of the way through the atmosphere and then a plane to get to orbit [9]. It’s a wild idea but seems plausible. The idea of going to space in balloons seems considerably scarier to me than the current space craft.
Interesting list of red team and physical entry gear with links to YouTube videos showing how to use them [10].
The Verge has an informative summary of the way Elon mismanaged Twitter after taking it over [11].
In May 2014 I bought a Samsung Galaxy Note 10.1 2014 edition tablet (wikipedia page [1]) with 32G of storage. It’s display is 2560×1600 resolution which still compares well to the latest tablets. The Galaxy Tab S8 [2] is the latest high-end tablet series from Samsung and the 11 inch tablet in that series also has a 2560×1600 giving it a slightly lower DPI! The latest series also has 12.4″ and 14.6″ tablets with resolutions of 2800×1752 and 2960×1848 respectively. Obviously if you want a 14″ tablet then the latest offerings are good, but if you want a 10″ or 11″ tablet then Samsung hasn’t improved much. The Note 10.1 has 3G of RAM and a choice of 16G, 32G, or 64G of storage. The latest Tab S8 tablets have 8G to 16G of RAM and 128G to 512G of internal storage, which are great if you need such things. For many tasks 3G of RAM is quite adequate and as I chose the 32G model I haven’t had a problem with storage. The s-pen is a feature of this tablet which is also on the latest high-end Samsung tablets, it is useful for accessing small elements in web sites designed for desktop use and for graphics editing.
One noteworthy feature of this tablet is the fact that when in “landscape” orientation it has speakers on each side, which is the correct layout as the vast majority of video with stereo sound is in a landscape orientation.
After using that tablet for about 4 years I bought myself a newer tablet and gave it to my wife. She has since passed it on to another relative who is using it regularly. That tablet seems to have lasted well still being quite usable when it’s almost 9 years old. The price including delivery was $579, that works out to about $1.30 per week (disregarding interest and inflation). According to the Reserve Bank of Australia inflation calculator [3] $579 in 2014 is equivalent to $652 in 2021, they don’t have results for later than 2021 so I’ll assume it would be $675 in 2023.
Currently the main problems with this tablet are lack of USB-C support (which means it’s difficult to connect to an external display among other things) and lack of a recent version of Android, 4.4.2 was the latest OTA update available. The XDA Developers forum has a section for this tablet [4] which includes discussion of updates to Android 5.x for devices which didn’t get it automatically and for upgrading to very recent Android versions in LineageOS. I’m idly considering one of those options, but for the current user the Google Play store is a requirement.
Newer Samsung Tablets
The current equivalent Samsung tablet is the Galaxy Tab S8 which is currently being sold for $1055 which is 56% higher than the inflation adjusted price of my tablet. I don’t think this is reasonable given that I bought it 7 months after release and it’s now 11 months since the release of the Tab S8. The Tab S8 has more RAM, more storage, and a faster CPU due to improvements over the entire computer industry – replacing old parts with newer versions of the same things (including changing to USB-C) doesn’t justify a price rise. Increasing RAM size by a factor of 3-5 and increasing storage by a factor of 8 over the last 9 years doesn’t match the industry trends for PCs, also as an aside my latest laptop only has 8G of RAM and works well for much more demanding tasks. The Tab S8 series also has significantly better cameras, but I don’t think that’s a big deal, the 2Mp front camera in my tablet can provide adequate quality for video conferencing and usually saturate the upload bandwidth and again that’s an issue of the entire industry moving to newer hardware. I don’t think it’s bad to take a form factor and display that works well and put newer versions of the CPU, RAM, storage, cameras, and OS on it. But asking for 56% more money for the updated tablet seems unreasonable.
The current S8 Ultra is going for $1760 and the S8+ is $1479. I think those are ridiculous prices for tablets as there is a decent range of new laptops that are cheaper. I believe that the purpose of a tablet is to be easy to carry and quick to start using (no waiting for a laptop to connect to wifi after leaving suspend). The largest of the S8 Tabs is about the same length and width as a Thinkpad X1 Carbon with the benefits being that it’s thinner and lighter, but if you got a tablet case with keyboard then it would be thicker and heavier. The S8 seems like bad value for money and the S8+ and S8 Ultra don’t seem to compare well to laptops and Chromebooks with touch screens unless you have a specific need for Android tablet apps.
If Samsung are going to just make new tablets without any significant improvements other than refreshing to the latest CPU, RAM, storage, and Camera technology and force users to upgrade via a lack of new OS support then they shouldn’t charge so much. Stick well below $1000 and people will be more inclined to replace items, expensive items are expected to last.
Conclusion
Buying this tablet was definitely a good choice. It has performed well for many years and after a couple of years of light use it’s back in daily use again. The value for money it offered was significantly greater than newer tablets, when it was new it was really high-end, the current S8 Tab series of tablets aren’t anything special when compared to other tablets.
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