Re: [gentoo-user] Re: How to find out to what file(...) writes goes on a idle system...

James <wireless@×××××××××××.com> [14-12-06 18:16]:
>  <meino.cramer <at> gmx.de> writes:
>
>
> > on different systems I see the write stats (/proc/dikstats) to
> > physical existing disks steadily increasing.
> > Looking at the output of lsof I cannot find any file suspicous
> > for receiving those writes.
>
> Ok so in my experiences you need a (2) pronged approach.
>
> (1) Then pursue quantifying with tools just what is causing the
> writes, strategies for minimization and monitoring as needed.
>
> So folks are going down path (1) with you, that is fine.
>
> (2) First minimize those write to your non-mechanical memory.
>
> Path (2)
> on any and all minimized gentoo or embedded gentoo systems,
> I start out with USE="-*" to keep things minimum. Yea that tweaks the
> devs now, but minimal system are just that, minimized, imho, so that
> is a firm standard I always operation on. Set the minimum
> number of global flags and the thinest  profile that will work for
> your system. Every flag invokes more code and hence more processes,
> more files, more writing to media.
>
> Also, all log files should be written off the embeded system via
> NFS or other similar mechanisms.
>
> If you want further help, put up a document where folks can spend
> $20 and get a similar board up and running embedded gentoo. Then
> they can see exactly what you see have and you can work as a team, or not,
> your call.
>
> I have dozens of tricks to minimize a gentoo system. But it is quite
> a bit of work, just so you know. It's not a do this and it great. It
> more like, try this, study the result and then alter the strategy.
>
> hth,
> James
>

Hi,

thank you very for all help I received regarding my question.

The system is already down to a limit. The by default running
processes are:


root         1     0  0 15:36 ?        00:00:00 init [3]  
root         2     0  0 15:36 ?        00:00:00 [kthreadd]
root         3     2  0 15:36 ?        00:00:01 [ksoftirqd/0]
root         5     2  0 15:36 ?        00:00:00 [kworker/0:0H]
root         7     2  0 15:36 ?        00:00:00 [khelper]
root         8     2  0 15:36 ?        00:00:00 [kdevtmpfs]
root       160     2  0 15:36 ?        00:00:00 [writeback]
root       162     2  0 15:36 ?        00:00:00 [crypto]
root       164     2  0 15:36 ?        00:00:00 [bioset]
root       166     2  0 15:36 ?        00:00:00 [kblockd]
root       168     2  0 15:36 ?        00:00:00 [cfg80211]
root       169     2  0 15:36 ?        00:00:00 [kworker/0:1]
root       280     2  0 15:36 ?        00:00:00 [kswapd0]
root       296     2  0 15:36 ?        00:00:00 [fsnotify_mark]
root       372     2  0 15:36 ?        00:00:00 [ipv6_addrconf]
root       398     2  0 15:36 ?        00:00:00 [deferwq]
root       406     2  0 15:36 ?        00:00:12 [mmcqd/0]
root       412     2  0 15:36 ?        00:00:00 [kworker/0:2]
root       415     2  0 15:36 ?        00:00:00 [jbd2/mmcblk0p2-]
root       416     2  0 15:36 ?        00:00:00 [ext4-rsv-conver]
root       563     1  0 15:37 ?        00:00:00 /lib/systemd/systemd-udevd --daemon
root       952     1  0 15:37 ?        00:00:00 /usr/sbin/ifplugd --iface=usb0
root      1380     1  0 15:37 ?        00:00:00 /usr/sbin/sshd
root      1399     1  0 15:37 tty1     00:00:00 /sbin/agetty 38400 tty1 linux
root      1400     1  0 15:37 tty2     00:00:00 /sbin/agetty 38400 tty2 linux
root      1401     1  0 15:37 tty3     00:00:00 /sbin/agetty 38400 tty3 linux
root      1402     1  0 15:37 tty4     00:00:00 /sbin/agetty 38400 tty4 linux
root      1403     1  0 15:37 tty5     00:00:00 /sbin/agetty 38400 tty5 linux
root      1404     1  0 15:37 tty6     00:00:00 /sbin/agetty 38400 tty6 linux
root      1405     1  0 15:37 ttyS0    00:00:00 /sbin/agetty -L 9600 ttyS0 vt100
root      1406  1380  0 15:37 ?        00:00:02 sshd: root@pts/0 
root      1412  1406  0 15:37 pts/0    00:00:00 screen -R -d
root      1414  1412  0 15:37 ?        00:00:01 SCREEN -R -d
root      1415  1414  0 15:37 pts/1    00:00:05 -/bin/zsh
root      1434     2  0 15:38 ?        00:00:00 [kworker/0:1H]
root      1866     2  0 15:43 ?        00:00:00 [kworker/u2:0]
root      8556     2  0 16:49 ?        00:00:00 [kworker/u2:2]

The count of getty processes may be decreaseable...but the rest is ok,
I think.

When I do a ftop I get no process, which have an open file handle for
writes...sometimes screen writes to utmp but thats it.

I suspect the swapfile I mounted as swapdevice for being guilty. 
I will deactivate that and we will see then.

When looking at /proc/diskstats: Will I see writes to FIFOs on the
disk as writes to the disk???
If YES...it would explain it...

Best regards,
Meino