Sysadmin

Long story short: you have launched your script/program but forgot to redirect the output to a file for later inspection. #!/usr/bin/python3 #sample endless running program that prints to stdout import time,datetime while True: print(datetime.datetime.now().time()) time.sleep(1) Using GNU Debugger you can re-attach to the process, then invoke the creation of a logfile and duplicate the file descriptor to make the system send the data to the new file, instead of the terminal: ...

Obiettivo vogliamo mantenere la stessa directory sincronizzata su due server linux. Questo significa che ogni aggiunta/rimozione/modifica di file in questa directory verrà automaticamente riportato sull’altro (salvo conflitti). Diamo per assunto che i due server siano raggiungibili via rete, ma per qualsiasi motivo non sia possibile collegare dello spazio disco condiviso. Implementazione Per raggiungere lo scopo, utilizzeremo il tool: csync2 su entrambi i server (che chiameremo nodo1 e nodo2), installiamo i pacchetti necessari: ...

I had a trouble with a long process running and wish to know how much I/O this process is doing, so I wrote this quick and dirty python 2.x script: import time,sys,datetime def read_stat(pid): f=open("/proc/%s/io" % pid ,"r") for line in f: if line.startswith('rchar'): rchar=line.split(':')[1] continue if line.startswith('wchar'): wchar=line.split(':')[1] continue f.close() return int(rchar),int(wchar) pid=sys.argv[1] r0,w0 = read_stat(pid) while 1: time.sleep(1) r1,w1 = read_stat(pid) print "%s\t\tr=%s\t\tw=%s" % (datetime.datetime.now().time(),r1-r0,w1-w0) r0,w0=r1,w1 You must give the process PID number as input to the script. In the output you get the read/write throughput of the process in bytes per second, for instance: ...

It’s always recommended to backup your data for safety, but for safety AND security let’s encrypt your backups! to compress and encrypt with ‘mypassword’: tar -Jcf - directory | openssl aes-256-cbc -salt -k mypassword -out backup.tar.xz.aes to decrypt and decompress: openssl aes-256-cbc -d -salt -k mypassword -in backup.tar.xz.aes | tar -xJ -f - Another trick with the tar command is useful for remote backups: tar -zcvfp - /wwwdata | ssh root@remote.server.com "cat > /backup/wwwdata.tar.gz" ...