This post appeared originally in our sysadvent series and has been moved here following the discontinuation of the sysadvent microsite
pv is a nice little tool that will take stdin and make a nice little
progress bar and displaying time elapsed, percentage completed (if size is known)
current throughput rate and the total data transferred and with an ETA.
So if you have a tool that can output it’s result on standard output or read from standard input, one can get a progress bar!
It’s nice to know that “data is flowing”.
Other examples
Send file with Netcat and get a nice progress-bar:
pv file | nc -w 1 example.com 3000
Get progress bar on tar output:
tar zcf - /directory | pv > backup.tar.gz
MySQL dump/restore:
mysqldump database | pv > database.sql
pv database.sql | mysql database
Limit the transfer rate and size of data over a pipe
cat /dev/zero | pv -L 3m -Ss 100m > /dev/null
Alarms made right
At my work, we’re very much dependent on alarms. The systems need to be operational 24/7. When unexpected issues arise, timely manual intervention may be essential. We need good monitoring systems to catch whatever is wrong and good alarm systems to make someone aware that something urgently needs attention. I would claim that we’re quite good at setting up, tuning, and handling alarms.
When I’m not at work, I’m often sailing, often single-handedly for longer distances. Alarms are important for ... [continue reading]