Gelukkig is er een WayBack kopie van de PDF die vroeger op 404 Pagina niet gevonden | KlikAanKlikUit stond.
–jeroen
Posted by jpluimers on 2019/05/24
Gelukkig is er een WayBack kopie van de PDF die vroeger op 404 Pagina niet gevonden | KlikAanKlikUit stond.
–jeroen
Posted in LifeHacker, Power User | Leave a Comment »
Posted by jpluimers on 2019/05/24
Some wizardry: [WayBack] vmkfstools | virtualhobbit.
This includes:
vmkfstools -V (yes, capital V is for VMFS rescan, as lowercase v is for verbose)Found after reading [WayBack] Datastore not mounted after reboot of ESXi5.5 |VMware Communities
Then found this: [Wayback] VMware Knowledge Base: Performing a rescan of the storage on an ESXi host (1003988); Using the ESXi Command Line Interface
…
- To search for new VMFS datastores, run this command:
vmkfstools -VNote: This command does not generate any output.
That solved my problem!
# vmkfstools -V # esxcfg-volume --list Scanning for VMFS-3/VMFS-5 host activity (512 bytes/HB, 2048 HBs). VMFS UUID/label: 532cd010-6e8c01d1-45be-001f29022aed/Raid6SSD Can mount: Yes Can resignature: Yes Extent name: naa.600605b00aa054a0ff000021022683ae:1 range: 0 - 1830143 (MB) # esxcfg-volume --mount 532cd010-6e8c01d1-45be-001f29022aed Mounting volume volume 532cd010-6e8c01d1-45be-001f29022aed
And there it was:
# df -h Filesystem Size Used Available Use% Mounted on ... VMFS-5 1.7T 1.6T 169.6G 91% /vmfs/volumes/Raid6SSD ...
Note you can mount non-persistent (--mount) or persistent (--persistent-mount) by both UUID and label, so there are four choices for mounting:
esxcfg-volume --mount UUID esxcfg-volume --mount label esxcfg-volume --persistent-mount UUID esxcfg-volume --persistent-mount label
–jeroen
Posted in ESXi5, ESXi5.1, ESXi5.5, ESXi6, ESXi6.5, Power User, Virtualization, VMware, VMware ESXi | Leave a Comment »
Posted by jpluimers on 2019/05/24
Some tips on pruning entries from the systemd journal:
For stock opensuse, this is also relevant, as it seems to allow indefinite growth: [WayBack] systemd – journald Settings likey need your attention
You can view disk usage with this command:
journalctl --disk-usage
–jeroen
Posted in *nix, Linux, Power User, systemd | Leave a Comment »
Posted by jpluimers on 2019/05/23
Most code I come across is in the red zone, exactly depicting why you want immutable constructs. Immutable constructs will never end-up in the red zone.
Image: [WayBack] Wayback Machine.
The red zone is just one quadrant on the mutability/shareability diagram and getting outside that red zone quadrant is key.
With processor cores now becoming ubiquitous: you cannot get outside of the “Shard” half, so you have to get outside of the “Mutable” half.
Explaining the why and how, is part of a few presentations that Kevlin Henney gave:
Related YouTube videos are below.
–jeroen
Posted in Conference Topics, Conferences, Development, Event, Multi-Threading / Concurrency, Software Development | Leave a Comment »
Posted by jpluimers on 2019/05/23
Too bad G+ doesn’t allow the WayBack machine or Archive.is to archive the whole thread at [WayBack] [Archive.is] Das es inzwischen fast überall Standard ist die Uhren mit einem guten Zeitsignal zu synchronisiseren (NTP, DCF-77, GPS etc) ist eigentlich eine gute Sache… – Kristian Köhntopp – Google+ so here are a few quotes below.
The generatel conclusions seem to be that:
This was the start:
Nils Ketelsen originally shared:
Guckt man live sieht es schon anders aus: Während die RunQueue meist so bei 4-5 liegt (bei 21vCPUs kein Problem) springt sie jede volle Minute einige Sekunden lang auf 20. Bei durch 2 Teilbaren Minuten auf ca. 40. Bei durch 10 Teilbaren Minuten auf 70, bei durch 15 teilbaren Minuten auf 150…. Ich habe eben durch einen schlecht getimten Toilettenbesuch die volle Stunde verpasst, das muss ich gleich mal anders hinbekommen, aber ich gehe davon aus, daß es da noch schlimmer ist.
And these some of the comments:
Posted in *nix, *nix-tools, Algorithms, cron, Development, Power User, Software Development | Leave a Comment »
Posted by jpluimers on 2019/05/23
Interesting thread that reminded me of the relatively new FastMM feature to track down lock contention and cope with it using release stacks:
[WayBack] I try use FastMM4 to tracking bottleneck in allocating memory. I was inspired by this Primož movie: https://www.youtube.com/watch?v=p-5mJyXvmrc When I… – Jacek Laskowski – Google+
The changes by Primož have added these two new conditional defines to the FastMM4 codebase:
LogLockContentionUseReleaseStack (note this option was not documented in FastMM4Options.inc)These options are mutually exclusive.
This was the original post it got introduced in [WayBack] The Delphi Geek: Finding Memory Allocation Bottlenecks with FastMM4 and merged into the main repository.
FastMM introduction: [WayBack] The New Memory Manager In BDS 2006 – by Pierre le Riche.
It also taught me about [WayBack] RAMDisk – Software that Accelerates, Protects, Optimizes – Server Memory Products & Services – Dataram.
Primož stores his DCU files there: much faster than SSD, and far less wear on your SSD; see https://youtu.be/p-5mJyXvmrc?t=2675
–jeroen
Posted in Conference Topics, Conferences, Delphi, Development, Event, FastMM, Software Development | Leave a Comment »
Posted by jpluimers on 2019/05/22
Since I always forget that IN and EXISTS have very different performance characteristics: [WayBack] sql – How to Select Every Row Where Column Value is NOT Distinct – Stack Overflow
select emailaddress,customername from customers where emailaddress in
(select emailaddress from customers group by emailaddress having count(*) > 1)
select emailaddress,customername from Customers a where exists
(select emailaddress from customers c where a.customerName != c.customerName and a.EmailAddress = c.EmailAddress)
–jeroen
Posted in Database Development, Development, Software Development, SQL | Leave a Comment »
Posted by jpluimers on 2019/05/22
Cool: [WayBack] Insentricity :: Kermit on the JAIR 8080 ::
Repository: [WayBack] FozzTexx/Kermit-CPM: Columbia University’s Kermit for CP/M
–jeroen
Posted in Assembly Language, Development, History, Software Development | Leave a Comment »
Posted by jpluimers on 2019/05/22
Thanks Ondrej Kelle for answering this:
uses
System.SysUtils,
Web.HTTPApp,
Soap.WebBrokerSOAP;
function TTest.CallMe: string;
var
WebDispatcher: IWebDispatcherAccess;
begin
Result := '';
if Supports(GetSOAPWebModule, IWebDispatcherAccess, WebDispatcher) then
Result := Format('You are calling me from: %s', [WebDispatcher.Request.RemoteIP]);
end;
Source: [WayBack] web services – Accessing the original TWebRequest object in a Delphi SOAP Server – Stack Overflow
–jeroen
Posted in Conference Topics, Conferences, Delphi, Development, Event, Software Development | Leave a Comment »
Posted by jpluimers on 2019/05/21
Context is king!
Being Dutch, my association with iota was the phrase “Ik snap er geen iota van” (English: “It’s all Greek to me”), basically indicating iota is extremely small, similar to [WayBack] Iota | Definition of Iota by Merriam-Webster:
2: the 9th letter of the Greek alphabet — see alphabet table
But the first time, I saw iota used in golang, I actually confused it with [WayBack] itoa – C++ Reference, because I am more than slightly wordblind.
So code like this was all Greek to me at first, not understanding the conversion from integer to ASCII**, and slightly later, not understanding iota to be extremely small either. Heck, its usage indicates it is small from infinitesimal:
const ( _ = iota // ignore first value by assigning to blank identifier KB ByteSize = 1 << (10 * iota) MB GB TB PB EB ZB YB )
So it took me a bit of thought to realise that it actually had to mean something completely different, so I found
iota count [start step] -> listReturns a list containing the elementsIt makes me wonder why they named it like this.
Slightly related:
Q
In the C language where did they come up with the name atoi for converting a string to an integer? The only thing I can think of is Array To Integer for an acronym but that doesn’t really make sense.
A
It means Ascii to Integer. Likewise, you can have
atolfor Ascii to Long,atoffor Ascii to Float, etc.A Google search for ‘atoi “ascii to integer”‘ confirms this on several pages.
I’m having trouble finding any official source on it… but in this listing of man pages from Third Edition Unix (1973) collected by Dennis Ritchie himself, it does contain the line:
atoi(III): convert ASCII to integerIn fact, even the first edition Unix (ca 1971) man pages list
atoias meaning Ascii to Integer.So even if there isn’t any documentation more official than man pages indicating that
atoimeans Ascii to Integer (I suspect there is and I just haven’t been able to locate it), it’s been Ascii to Integer by convention at least since 1971.
atoi -- ascii to integer–jeroen
Posted in C++, Development, Go (golang), Software Development | Leave a Comment »