Display the number of I/O to disk (reads/writes) since the last boot on CentOS – Managing your servers can streamline the performance of your team by allowing them to complete complex tasks faster. Plus, it can enable them to detect problems early on before they get out of hand and compromise your business. As a result, the risk of experiencing operational setbacks is drastically lower.
But the only way to make the most of your server management is to perform it correctly. And to help you do so, this article will share nine tips on improving your server management and fix some problem about linux, storage, , , .
Is it possible to use iostat (or some other tool) to get the number of reads/writes operation “since the last server reboot”?
I mean: I’d need to know how many reads/writes the server has done since the last boot, not in realtime.
For the amount of data, see
[root@example ~]# iostat -m Linux 2.6.32-431.11.2.el6.x86_64 (example.com) 08/08/2014 _x86_64_ (2 CPU) avg-cpu: %user %nice %system %iowait %steal %idle 0.38 0.00 4.10 0.36 0.10 95.07 Device: tps MB_read/s MB_wrtn/s MB_read MB_wrtn sda 0.95 0.01 0.01 68451 77290 vda 13.95 0.26 0.33 2871276 3572093 dm-0 1.93 0.01 0.01 64657 73426 dm-1 14.39 0.26 0.33 2871274 3572093
-m will display the output in MiB (instead of blocks), and the
MB_wrtn are the numbers you are looking for.
For the total amount of I/O operations (requests), see
/proc/diskstats, which can be interpreted as follows (this is from the kernel doc tree):
What: /proc/diskstats Date: February 2008 Contact: Jerome Marchand <email@example.com> Description: The /proc/diskstats file displays the I/O statistics of block devices. Each line contains the following 14 fields: 1 - major number 2 - minor mumber 3 - device name 4 - reads completed successfully 5 - reads merged 6 - sectors read 7 - time spent reading (ms) 8 - writes completed 9 - writes merged 10 - sectors written 11 - time spent writing (ms) 12 - I/Os currently in progress 13 - time spent doing I/Os (ms) 14 - weighted time spent doing I/Os (ms) For more details refer to Documentation/iostats.txt