A few corrections and clarifications to r343406.

- Use "in" instead of "on" when referring to directory and UFS partition.
- Switch from hw.physmem to hw.realmem and add a description to
distinguish the two.
- Explain why the "df" command is having trouble displaying ZFS sizes
correctly. Add a bit more descriptive text to help why the output of
"zfs list -o space" should be used.
- Switch to vmstat instead of iostat display for systat(1) as it shows
more information on one screen. Describe what is displayed based on the
text of the man page. Change the list of the other values accordingly.
- Sort the flags to "zfs destroy" alphabetically.

Reviewed by:	rgrimes
Approved by:	rgrimes
MFC after:	8 days
Differential Revision:	https://reviews.freebsd.org/D18993
This commit is contained in:
bcr 2019-01-28 19:54:58 +00:00
parent b9c93879aa
commit 789fcc7599

View File

@ -275,7 +275,7 @@ To see how much disk space is left on your UFS partitions, use
df -h
-- Dru <genesis@istar.ca>
%
To see the 10 largest files on a directory or UFS partition, use
To see the 10 largest files in a directory or on a UFS partition, use
du -h /partition_or_directory_name | sort -rh | head
-- Dru <genesis@istar.ca>
@ -560,10 +560,13 @@ curl -v -d "nickname=$USER" -d "description=FreeBSD/$(uname -m) on \
$(kenv smbios.system.maker) $(kenv smbios.system.product)" -d "do=addd" \
--data-urlencode 'dmesg@/var/run/dmesg.boot' http://dmesgd.nycbug.org/index.cgi
%
Want to know how much memory (in bytes) your machine has available? Let
Want to know how much memory (in bytes) your machine has installed? Let
sysctl(8) tell you with the following command:
sysctl hw.physmem
sysctl hw.realmem
The realmem value is memory before the kernel and modules are loaded, whereas
hw.physmem is what is left after they were loaded.
The number of active CPUs is displayed using this command:
@ -571,20 +574,24 @@ sysctl hw.ncpu
-- Benedict Reuschling <bcr@FreeBSD.org>
%
When using ZFS as the file system the "df" command will display confusing
values. Use the built-in "zfs list" command to get an overview of space usage:
When using ZFS as the file system the "df" command is reporting the pool size
and not file system sizes. It also does not know about descendent ZFS
datasets, snapshots, quotas, and reservations with their individual space usage.
Use the built-in "zfs list" command to get a better overview of space usage:
zfs list -o space
-- Benedict Reuschling <bcr@FreeBSD.org>
%
To learn more about what your system is doing, take a look at systat(1). For
example, to get an overview of I/O happening in the system, run:
example, to get various of statistics related to virtual memory usage, process
scheduling, device interrupts, system name translation caching, and disk I/O,
enter the following:
systat -iostat
systat -vmstat
Other values are icmp, icmp6, ifstat, ip, ip6, netstat, pigs, sctp, swap, tcp,
vmstat, or zarc. You can switch between displays using :<display> and exit
Other values are icmp, icmp6, ifstat, iostat, ip, ip6, netstat, pigs, sctp,
swap, tcp, or zarc. You can switch between displays using :<display> and exit
back to your shell by typing
:quit
@ -694,7 +701,7 @@ dataset/snapshot and not any dependent ones. ZFS will display the resulting
action when -n is combined with the -v option without actually performing
it:
zfs destroy -rvn mypool@mysnap
zfs destroy -nrv mypool@mysnap
Once you are sure this is exactly what you intend to do, remove the -n
parameter to execute the destroy operation.