A pity… another good service disappears from the web…
We regret to inform you that as of May 1, 2015, the RSS Graffiti application will no longer be available to serve you. Please ensure that you transition your account. For more information, please visit http://www.rssgraffiti.com
Some time ago someone asked me to write my own implementation of the hyperbolic cosine (http://pl.wikipedia.org/wiki/Funkcje_hiperboliczne) based on the Taylor series.
A quick proof-of-concept version:
#include <stdio.h>
#include <stdlib.h>
#include <math.h>
double silnia (double n){
if (n <= 1) return 1;
else return silnia(n - 1)*n;
}
double mycosh(double z){
double result = 1;
int ilosc_wyr_ciagu = 30;
int i;
for (i = 1; i < ilosc_wyr_ciagu; i++){
result += pow(z, 2*i) / silnia(2*i);
}
return result;
}
int main(int argc, char *argv[]) {
double arg, c1, c2, blad;
arg = 3.113408;
c1 = cosh(arg);
c2 = mycosh(arg);
blad = abs(c2-c1)/c2;
printf(" z=%f; cosh(z)=%f; mycosh(z)=%f; blad=%.90f \n", arg, c1, c2, blad);
system("PAUSE");
return 0;
}
To force detection of newly added disks in Linux running as a virtual machine under VMware:
echo "- - -" > /sys/class/scsi_host/host#/scan fdisk -l tail -f /var/log/message
After a few surprises that appeared less than a month ago in the article https://www.karolszczepanowski.pl/2015/02/24/problemy-z-vmware-vcenter-server-5-5/, it was time for another one…
This time the vCenter database stopped with the not very informative note “(Suspect)”, probably because something broke after a power failure (again).
Fortunately someone has already described the problem, so here is the source link:
http://www.vmdude.fr/en/tips-tricks-en/suspect-vcenter-database-on-sql-express/
A collection of a few problems I recently encountered with vCenter…
Problem: entries in the log C:\ProgramData\VMware\VMware VirtualCenter\Logs\Vpxd-XXX.log:
2015-02-03T17:04:41.874+01:00 [06244 error 'win32vpxLdap_win32'] [LDAP Client] Failed to add LDAP entry CN=396B4052-A620-474B-BE8E-0446D1E1E831,OU=ComponentSpecs,OU=Health,dc=virtualcenter,dc=vmware,dc=int: 0x68 (The object already exists.)
Problem: entries in C:\ProgramData\VMware\VMware VirtualCenter\Logs\wrapper.log:
INFO | jvm 1 | 2015/02/02 17:09:21 | SEVERE: Unable to expose the remote JMX registry. INFO | jvm 1 | 2015/02/02 17:09:21 | java.lang.IllegalArgumentException: Port value out of range: -1
Solution: VMware documentation
In short: edit the base.jmx.port variable in C:\Program Files\VMware\Infrastructure omcat\conf\catalina.properties:
base.jmx.port=-1
change it to:
base.jmx.port=6969
Problem: how to restore the configuration, in other words generally about configuration backup (but this is worth doing earlier ;-P).
Solution: VMware KB 1029864
Problem: where are the logs stored?
Solution: typical log locations:
C:\ProgramData\VMware\Infrastructure\Inventory Service\Logs C:\ProgramData\VMware\VMware VirtualCenter\Logs
Problem: what does the vCenter database structure look like?