--- 09_systips.txt	2014-01-26 21:32:19.035513078 +0100
+++ 09_systips_proposal.txt	2014-06-03 23:15:56.777649202 +0200
@@ -7,7 +7,7 @@
 
 === The screen program
 
-`screen`(1) is a very useful tool for people to access remote sites via unreliable or intermittent connections since it support interrupted network connections.
+`screen`(1) is a very useful tool for people to access remote sites via unreliable or intermittent connections since it supports interrupted network connections.
 
 .List of programs to support interrupted network connections
 [grid="all"]
@@ -117,7 +117,7 @@
 $ vim cleanedfile
 --------------------
 
-If you don't have `script` (for example, during the boot process in the initramfs), you can use following instead.
+If you don't have `script` (for example, during the boot process in the initramfs), you can use the following instead.
 
 --------------------
 $ sh -i 2>&1 | tee typescript
@@ -274,11 +274,13 @@
 `time`      @-@popcon1@-@ @-@psize1@-@ `time`(1): run a program to report system resource usages with respect to time
 `sysstat`   @-@popcon1@-@ @-@psize1@-@ `sar`(1), `iostat`(1), `mpstat`(1), ...: system performance tools for Linux
 `isag`      @-@popcon1@-@ @-@psize1@-@ Interactive System Activity Grapher for sysstat
-`lsof`      @-@popcon1@-@ @-@psize1@-@ `lsof`(8): list open files by a running process using "`-p`" option
+`lsof`      @-@popcon1@-@ @-@psize1@-@ `lsof`(8): list files opened by a running process using "`-p`" option
 `strace`    @-@popcon1@-@ @-@psize1@-@ `strace`(1): trace system calls and signals
 `ltrace`    @-@popcon1@-@ @-@psize1@-@ `ltrace`(1): trace library calls
 `xtrace`    @-@popcon1@-@ @-@psize1@-@ `xtrace`(1): trace communication between X11 client and server
 `powertop`  @-@popcon1@-@ @-@psize1@-@ `powertop`(1): information about system power use on Intel-based laptops
+### HW: powertop -> *on*Intel-based*laptops*: is this still true? According to the package
+### HW: description it is not (no longer?) limited so some specific CPU type or arch.
 `cron`      @-@popcon1@-@ @-@psize1@-@ run processes according to a schedule in background from `cron`(8) daemon
 `anacron`   @-@popcon1@-@ @-@psize1@-@ cron-like command scheduler for systems that don't run 24 hours a day
 `at`        @-@popcon1@-@ @-@psize1@-@ `at`(1) or `batch`(1): run a job at a specified time or below certain load level
@@ -320,7 +322,7 @@
 
 ==== The ps command
 
-The `ps`(1) command on the Debian support both BSD and SystemV features and helps to identify the process activity statically.
+The `ps`(1) command on a Debian system support both BSD and SystemV features and helps to identify the process activity statically.
 
 .List of ps command styles
 [grid="all"]
@@ -337,7 +339,7 @@
 
 ==== The top command
 
-`top`(1) on the Debian has rich features and helps to identify what process is acting funny dynamically.
+`top`(1) on the Debian system has rich features and helps to identify what process is acting funny dynamically.
 
 .List of commands for top
 [grid="all"]
@@ -351,6 +353,11 @@
 `k`         kill a process
 `r`         renice a process
 `q`         quit the `top` command
+### HW: this list is no longer up-to-date it seems (I have the procps package v3.3.3-3
+### HW: from Wheezy here):
+### HW: "f"/"F" is now "Manage fields", apparently there is no difference between f and F.
+### HW: "o" is no longer supported.
+### HW: Set sort field is now via pressing "s" while in the Field Management (f/F).
 ----------------------------------------
 
 ==== Listing files opened by a process
@@ -361,7 +368,7 @@
 $ sudo lsof -p 1
 --------------------
 
-PID=1 is usually `init` program.
+PID=1 is usually the `init` program.
 
 ==== Tracing program activities
 
@@ -441,6 +448,7 @@
 
 You can set up to start a process from http://en.wikipedia.org/wiki/Graphical_user_interface[graphical user interface (GUI)].
 
+### HW: maybe the following is no longer true for GNOME3? Read further for more info.
 Under GNOME desktop environment, a program can be started with proper argument by **double-clicking** the launcher icon, by **drag-and-drop** of a file icon to the launcher icon, or by "**Open with ...**" menu via right clicking a file icon.  KDE can do the equivalent, too.
 
 Here is an example under GNOME to create a launcher icon for `mc`(1) started in `gnome-terminal`(1).
@@ -457,6 +465,13 @@
 
 Create a desktop launcher as the following.
 
+### HW: In GNOME3 here on my test machine, I cannot choose "Create Launcher" 
+### HW: when right-clicking on the desktop, there is no such entry.
+### HW: IMO the following is no longer up-to-date, it's for GNOME2 I think,
+### HW: and we have GNOME3 in stable now. Or maybe I have to install some
+### HW: optional package, to get that feature? I simply installed the "gnome"
+### HW: metapackage. Ah, wait, I'm running GNOME3 in fallback mode, there seems
+### HW: to be a problem with the graphics card. Maybe that's the reason?
 1. Right click desktop space to select "`Create Launcher ...`".
 2. Set "Type" to "`Application`".
 3. Set "Name" to "`mc`".
@@ -565,14 +580,17 @@
 `r`                     restore the keyboard from **r**aw mode after X crashes
 `0`                     change the console loglevel to **0** to reduce error messages
 `k`                     **k**ill all processes on the **current virtual console**
-`e`                     send a SIGT**E**RM to all processes, except for `init`(8)
-`i`                     send a SIGK**I**LL to all processes, except for `init`(8)
-`s`                     **s**ync all mounted filesystems
+### HW: rephrase the following terms, to explain what SIGTERM | SIGKILL does
+`e`                     try to stop all processes, except for `init`(8), with a SIGT**E**RM
+`i`                     kill all processes, except for `init`(8), with a SIGK**I**LL
+### HW: rephrase the following, to explain what sync is
+`s`                     **s**ync all mounted filesystems (write filesystem buffers to disc)
 `u`                     remount all mounted filesystems read-only (**u**mount)
 `b`                     re**b**oot the system without syncing or unmounting
 ---------------------------------------------------------------------------------------------------------------
 
-The combination of "Alt-SysRq s", "Alt-SysRq u", and "Alt-SysRq r" is good for getting out of really bad situations.
+### HW: I assume you meant "sync + umount ro + reboot" here, right? But reboot is b, not r.
+The combination of "Alt-SysRq s", "Alt-SysRq u", and "Alt-SysRq b" is good for getting out of really bad situations.
 
 See "`/usr/share/doc/linux-doc-3.\*/Documentation/sysrq.txt.gz`".
 
@@ -591,7 +609,8 @@
 - `last`(1)  shows listing of last logged in user.
 - `lastb`(1) shows listing of last bad logged in users.
 
-TIP: "`/var/run/utmp`", "`/var/log/wtmp`", and "`/var/run/utmp`" hold such user information.  See `login`(1) and `utmp`(5).
+### HW: /var/run/utmp is mentioned two times in the next line!
+TIP: "`/var/run/utmp`", and "`/var/log/wtmp`" hold such user information.  See `login`(1) and `utmp`(5).
 
 ==== Warning everyone
 
@@ -603,7 +622,7 @@
 
 ==== Hardware identification
 
-For the http://en.wikipedia.org/wiki/Peripheral_Component_Interconnect[PCI]-like devices (http://en.wikipedia.org/wiki/Accelerated_Graphics_Port[AGP], http://en.wikipedia.org/wiki/PCI_Express[PCI-Express], http://en.wikipedia.org/wiki/PC_Card#CardBus[CardBus], http://en.wikipedia.org/wiki/ExpressCard[ExpressCard], etc.), `lspci`(8) (probably with "`-nn`" option) is a good start for the hardware identification
+For the http://en.wikipedia.org/wiki/Peripheral_Component_Interconnect[PCI]-like devices (http://en.wikipedia.org/wiki/Accelerated_Graphics_Port[AGP], http://en.wikipedia.org/wiki/PCI_Express[PCI-Express], http://en.wikipedia.org/wiki/PC_Card#CardBus[CardBus], http://en.wikipedia.org/wiki/ExpressCard[ExpressCard], etc.), `lspci`(8) (probably with "`-nn`" option) is a good start for the hardware identification.
 
 Alternatively, you can identify the hardware by reading contents of "`/proc/bus/pci/devices`" or browsing directory tree under "`/sys/bus/pci`" (see <<_procfs_and_sysfs>>).
 
@@ -662,9 +681,12 @@
 # hwclock --show
 --------------------
 
-Times are normally displayed in the local time on the Debian system but the hardware and system time usually use http://en.wikipedia.org/wiki/Universal_Time[UT(GMT)].
+### HW: Why not use "UTC" here? It's IMHO more correct than "UT". According to Wikipedia,
+### HW: there are several different versions of UT, one of them is UTC, another one is UT1.
+### HW: Here actually used is UTC IMHO (see "UTC=yes in /etc/default/rcS").
+Times are normally displayed in the local time on the Debian system but the hardware and system time usually use http://en.wikipedia.org/wiki/UTC[UTC(GMT)].
 
-If the hardware (BIOS) time is set to UT, change the setting to "`UTC=yes`" in the "`/etc/default/rcS`".
+If the hardware (BIOS) time is set to UTC, change the setting to "`UTC=yes`" in the "`/etc/default/rcS`".
 
 If you wish to update system time via network, consider to use the http://en.wikipedia.org/wiki/Network_Time_Protocol[NTP] service with the packages such as `ntp`, `ntpdate`, and `chrony`.
 
@@ -690,7 +712,7 @@
 
 Device drivers for sound cards for current Linux are provided by http://en.wikipedia.org/wiki/Advanced_Linux_Sound_Architecture[Advanced Linux Sound Architecture (ALSA)].  ALSA provides emulation mode for previous http://en.wikipedia.org/wiki/Open_Sound_System[Open Sound System (OSS)] for compatibility.
 
-TIP: Use "`cat /dev/urandom > /dev/audio`" or `speaker-test`(1) to test speaker. (\^C to stop)
+TIP: Use "`cat /dev/urandom > /dev/audio`" or `speaker-test`(1) to test speaker (\^C to stop).
 
 TIP: If you can not get sound, your speaker may be connected to a muted output.  Modern sound system has many outputs.  `alsamixer`(1) in the `alsa-utils` package is useful to configure volume and mute settings.
 
@@ -736,7 +758,8 @@
 
 One can always unplug the PC speaker to disable beep sounds.  Removing `pcspkr` kernel module does this for you.
 
-The following prevents the `readline`(3) program used by `bash`(1) to beep when encountering "`\a`" (ASCII=7).
+### HW: explain what this \a thing is? (for newbies like me :-))
+The following prevents the `readline`(3) program used by `bash`(1) to beep when encountering an alert ("`\a`", ASCII=7).
 
 --------------------
 $ echo "set bell-style none">> ~/.inputrc
@@ -744,6 +767,10 @@
 
 ==== Memory usage
 
+### HW: This chapter is likely to confuse users IMHO, at least on a short glance.
+### HW: Quoting user: "dmesg tells me a free of 990 MB, and free -k says 320 MB is free.
+### HW: That's a difference of more than 600 MB. What the h**l is that?"
+### HW: Probably explain that a bit more?
 The kernel boot message in the "`/var/log/dmesg`" contains the total exact size of available memory.
 
 `free`(1) and `top`(1) display information on memory resources on the running system.
@@ -758,7 +785,7 @@
 Swap:      4545576          4    4545572
 --------------------
 
-TIP: Do not worry about the large size of "`used`" and the small size of "`free`" in the "`Mem:`" line, but read the one under them (675404 and 321780 in the example below) and relax.
+TIP: Do not worry about the large size of "`used`" and the small size of "`free`" in the "`Mem:`" line, but read the one under them (675404 and 321780 in the example above) and relax.
 
 For my MacBook with 1GB=1048576k DRAM (video system steals some of this), I see the following.
 
@@ -779,9 +806,9 @@
 
 For system security and integrity check, you should start with the following.
 
-- The `debsums` package, See `debsums`(1) and <<_top_level_release_file_and_authenticity>>.
-- The `chkrootkit` package, See `chkrootkit`(1).
-- The `clamav` package family, See `clamscan`(1) and `freahclam`(1).
+- The `debsums` package, see `debsums`(1) and <<_top_level_release_file_and_authenticity>>.
+- The `chkrootkit` package, see `chkrootkit`(1).
+- The `clamav` package family, see `clamscan`(1) and `freshclam`(1).
 - http://www.debian.org/security/faq[Debian security FAQ].
 - http://www.debian.org/doc/manuals/securing-debian-howto/[Securing Debian Manual].
 
@@ -812,7 +839,7 @@
 
 === Data storage tips
 
-Booting your system with Linux http://en.wikipedia.org/wiki/Live_CD[live CDs] or http://www.debian.org/releases/stable/debian-installer/[debian-installer CDs] in rescue mode make it easy for you to reconfigure data storage on your boot device.
+Booting your system with Linux http://en.wikipedia.org/wiki/Live_CD[live CDs] or http://www.debian.org/releases/stable/debian-installer/[debian-installer CDs] in rescue mode makes it easy for you to reconfigure data storage on your boot device.
 
 ==== Disk space usage
 
@@ -888,7 +915,7 @@
 - `mkfs.ext4`(8) to create new http://en.wikipedia.org/wiki/Ext4[ext4] filesystem
 - `fsck.ext4`(8) to check and to repair existing http://en.wikipedia.org/wiki/Ext4[ext4] filesystem
 - `tune2fs`(8) to configure superblock of http://en.wikipedia.org/wiki/Ext4[ext4] filesystem
-- `debugfs`(8) to debug http://en.wikipedia.org/wiki/Ext4[ext4] filesystem interactively. (it has `undel` command to recover deleted files.)
+- `debugfs`(8) to debug http://en.wikipedia.org/wiki/Ext4[ext4] filesystem interactively. (It has `undel` command to recover deleted files.)
 
 The `mkfs`(8) and `fsck`(8) commands are provided by the `e2fsprogs` package as front-ends to various filesystem dependent programs (`mkfs.fstype` and `fsck.fstype`). For http://en.wikipedia.org/wiki/Ext4[ext4] filesystem, they are `mkfs.ext4`(8) and `fsck.ext4`(8) (they are hardlinked to `mke2fs`(8) and `e2fsck`(8)).
 
@@ -915,7 +942,7 @@
 
 TIP: http://en.wikipedia.org/wiki/Btrfs[Btrfs] filesystem is available in Linux kernel 3.2 (Debian `wheezy`).  It is expected to be the next default filesystem after the ext4 filesystem.
 
-WARNING:  You should not use the Btrfs filesystem for your critical data yet before it aquires the live kernel space `fsck`(8) feature and the boot loader support.
+WARNING:  You should not use the Btrfs filesystem for your critical data yet before it acquires the live kernel space `fsck`(8) feature and the boot loader support.
 
 TIP: Some tools allow access to filesystem without Linux kernel support (see <<_manipulating_files_without_mounting_disk>>).
 
@@ -947,7 +974,7 @@
 
 - "`defaults`" option implies default options: "`rw,suid,dev,exec,auto,nouser,async`". (general)
 - "`noatime`" or "`relatime`" option is very effective for speeding up the read access. (general)
-- "`user`" option allows an ordinary user to mount the filesystem. This option implies "`noexec,nosuid,nodev`" option combination. (general, used for CD and floppy)
+- "`user`" option allows an ordinary user to mount the filesystem. This option implies "`noexec,nosuid,nodev`" option combination. (general, used for CDs or usb storage devices)
 - "`noexec,nodev,nosuid`" option combination is used to enhance security. (general)
 - "`noauto`" option limits mounting by explicit operation only. (general)
 - "`data=journal`" option for ext3fs can enhance data integrity against power failure with some loss of write speed.
@@ -963,6 +990,9 @@
 - Execution of "`sudo tune2fs -j /dev/hda1`" adds journaling capability to the filesystem, i.e. filesystem conversion from http://en.wikipedia.org/wiki/Ext2[ext2] to http://en.wikipedia.org/wiki/Ext3[ext3] on "`/dev/hda1`".  (Do this on the unmounted filesystem.)
 - Execution of "`sudo tune2fs -O extents,uninit_bg,dir_index /dev/hda1 && fsck -pf /dev/hda1`" converts it from http://en.wikipedia.org/wiki/Ext3[ext3] to http://en.wikipedia.org/wiki/Ext4[ext4] on "`/dev/hda1`".  (Do this on the unmounted filesystem.)
 
+### HW: Is the following warning still reasonable? The referenced bug is tagged 'wontfix', 
+### HW: and apparently nothing changed since 2009. And linux 2.6 is long out-of-date.
+### HW: Moreover, grub is somewhat outdated, and grub2 is apparently not suffered from this.
 WARNING: Filesystem conversion for the boot device to the http://en.wikipedia.org/wiki/Ext4[ext4] filesystem should be avoided until http://bugs.debian.org/511121[GRUB boot loader supports the ext4 filesystem well] and installed Linux Kernel version is newer than 2.6.30.
 
 TIP: Despite its name, `tune2fs`(8) works not only on the http://en.wikipedia.org/wiki/Ext2[ext2] filesystem but also on the http://en.wikipedia.org/wiki/Ext3[ext3] and http://en.wikipedia.org/wiki/Ext4[ext4] filesystems.
@@ -994,7 +1024,7 @@
  * Set "`commit=600`" mount option in `/etc/fstab`. See `fstab`(5).
  * Set pm-utils to use laptop-mode even under AC operation. See http://bugs.debian.org/659260[Debian BTS #659260].
 
-WARNING: Changing flushing interval from normal 5 seconds to 10 minutes makes your data venerable to the power failure.
+WARNING: Changing flushing interval from normal 5 seconds to 10 minutes makes your data vulnerable to the power failure.
 
 ==== Using SMART to predict hard disk failure
 
@@ -1083,7 +1113,8 @@
 
 ==== Making the disk image file
 
-The disk image file, "`disk.img`", of an unmounted device, e.g., the second SCSI drive "`/dev/sdb`", can be made using `cp`(1) or `dd`(1) by the following.
+### HW: /dev/sdb is SCSI or serial ATA nowadays.
+The disk image file, "`disk.img`", of an unmounted device, e.g., the second SCSI or serial ATA drive "`/dev/sdb`", can be made using `cp`(1) or `dd`(1) by the following.
 
 --------------------
 # cp /dev/sdb disk.img
@@ -1100,9 +1131,10 @@
 
 - "`mbr.img`": The MBR with the partition table
 - "`mbr-nopart.img`": The MBR without the partition table
-- "`part.img`": The partition table of the MBR only
+- "`mbr-part.img`": The partition table of the MBR only
 
-If you have a SCSI device (including the new serial ATA drive) as the boot disk, substitute "`/dev/hda`" with "`/dev/sda`".
+### HW: Serial ATA is no longer new, isn't it :-)
+If you have an SCSI or serial ATA device as the boot disk, substitute "`/dev/hda`" with "`/dev/sda`".
 
 If you are making an image of a disk partition of the original disk, substitute "`/dev/hda`" with "`/dev/hda1`" etc.
 
@@ -1313,6 +1345,11 @@
 # mount -t iso9660 -o ro,loop cd.iso /cdrom
 --------------------
 
+### HW: don't know what the following line (auto-mounting of removable media)
+### HW: has to do with mounting an iso file. The iso file will never be
+### HW: automatically mounted IMHO, so why mention the auto-mount of CDs here?
+### HW: It may indeed confuse users, as they might think, the mount of iso
+### HW: file should work automatically.
 TIP: Modern desktop system mounts removable media automatically (see <<_removable_storage_device>>).
 
 === The binary data
@@ -1446,13 +1483,13 @@
 # dd if=/dev/zero of=/dev/sda
 --------------------
 
-Erase all by overwriting random data with the following.
+Erase everything by overwriting with random data as follows.
 
 --------------------
 # dd if=/dev/urandom of=/dev/sda
 --------------------
 
-Erase all by overwriting random data very efficiently with the following.
+Erase everything by overwriting with random data very efficiently as follows.
 
 --------------------
 # shred -v -n 1 /dev/sda
@@ -1493,7 +1530,7 @@
 # umount /dev/sdb1
 --------------------
 
-WARNING: This is usually a good enough for your USB memory stick.  But this is not perfect.  Most parts of erased filenames and their attributes may be hidden and remain in the filesystem.
+WARNING: This is usually good enough for your USB memory stick.  But this is not perfect.  Most parts of erased filenames and their attributes may be hidden and remain in the filesystem.
 
 ==== Undeleting deleted but still open files
 
@@ -1553,7 +1590,7 @@
 
 ==== Invisible disk space consumption
 
-All deleted but open files consumes disk space although they are not visible from normal `du`(1).  They can be listed with their size by the following.
+All deleted but open files consume disk space although they are not visible from normal `du`(1).  They can be listed with their size by the following.
 
 --------------------
 # lsof -s -X / |grep deleted
@@ -1587,7 +1624,7 @@
 
 ==== Removable disk encryption with dm-crypt/LUKS
 
-You can encrypt contents of removable mass devices, e.g. USB memory stick on "`/dev/sdx`", using http://en.wikipedia.org/wiki/Dm-crypt[dm-crypt]/http://en.wikipedia.org/wiki/Linux_Unified_Key_Setup[LUKS].  You simply formatting it as the following.
+You can encrypt contents of removable mass devices, e.g. USB memory stick on "`/dev/sdx`", using http://en.wikipedia.org/wiki/Dm-crypt[dm-crypt]/http://en.wikipedia.org/wiki/Linux_Unified_Key_Setup[LUKS].  You simply format it as the following.
 
 --------------------
 # badblocks -c 1024 -s -w -t random -v /dev/sdx
@@ -1606,9 +1643,9 @@
 # cryptsetup luksClose sdx1
 --------------------
 
-Then, it can be mounted just like normal one on to "`/media/<disk_label>`", except for asking password (see <<_removable_storage_device>>) under modern desktop environment, such as GNOME using `gnome-mount`(1).  The difference is that every data written to it is encrypted.  You may alternatively format media in different file format, e.g., ext4 with "`mkfs.ext4 /dev/sdx1`".
+Then, it can be mounted just like normal one on to "`/media/<disk_label>`", except for asking password (see <<_removable_storage_device>>) under modern desktop environment, such as GNOME using `gnome-mount`(1).  The difference is that every data written to it is encrypted.  You may alternatively format media in different filesystem, e.g., ext4 with "`mkfs.ext4 /dev/mapper/sdx1`".
 
-NOTE: If you are really paranoid for the security of data, you may need to overwrite multiple times in the above example.  This operation is very time consuming though.
+NOTE: If you are really paranoid for the security of data, you may need to overwrite multiple times (the "`badblocks`" command in the above example).  This operation is very time consuming though.
 
 // TIP: `shred`(1) is a tool to erase data.
 
@@ -1687,7 +1724,7 @@
 
 - Devices are created by the udev system (see <<_the_udev_system>>).
 - Read/write accesses to IDE CD/DVD devices do not use the `ide-scsi` module.
-- Network packet filtering functions use `iptable` kernel modules.
+- Network packet filtering functions use `iptables` kernel modules.
 
 The version bump from Linux 2.6.39 to Linux 3.0 is not about major technological changes but about the 20th anniversary.
 
@@ -1732,6 +1769,9 @@
 
 NOTE: When compiling the latest Linux kernel on the Debian `stable` system, the use of backported latest tools from the Debian `unstable` may be needed.
 
+### HW: In the next line you mention "Squeeze" explicitly. 
+### HW: Probably this is no longer true in the meantime? 
+### HW: Use something like "Squeeze and later" maybe?
 NOTE: The http://en.wikipedia.org/wiki/Dynamic_Kernel_Module_Support[dynamic kernel module support (DKMS)] is a new distribution independent framework designed to allow individual kernel modules to be upgraded without changing the whole kernel. This will be endorsed for the maintenance of out-of-tree modules for `squeeze`.  This also makes it very easy to rebuild modules as you upgrade kernels.
 
 ==== Compiling the kernel source: Debian Kernel Team recommendation
@@ -1791,7 +1831,7 @@
 
 Use of virtualized system enables us to run multiple instances of system simultaneously on a single hardware.
 
-TIP: See http://wiki.debian.org/SystemVirtualization .
+TIP: See http://wiki.debian.org/SystemVirtualization.
 
 ==== Virtualization tools
 
@@ -1833,7 +1873,7 @@
 
 ====  Virtualization work flow
 
-NOTE: Some functionalities described here are only available in `squeeze`.
+NOTE: Some functionalities described here are only available in `squeeze` or later.
 
 NOTE: Default Debian kernels support http://en.wikipedia.org/wiki/Kernel-based_Virtual_Machine[KVM] since `lenny`.
 
@@ -1848,7 +1888,7 @@
  * For the raw disk image file, mount it as http://en.wikipedia.org/wiki/Loop_device[loop device] or http://en.wikipedia.org/wiki/Device_mapper[device mapper] devices (see <<_mounting_the_disk_image_file>>).
  * For disk images supported by http://en.wikipedia.org/wiki/QEMU[QEMU], mount them as http://en.wikipedia.org/wiki/Network_block_device[network block device] (see <<_mounting_the_virtual_disk_image_file>>).
 - Populate the target filesystem with required system data.
- * Use programs such as `debootstrap` and `cdebootstrap` help this process (see <<_chroot_system>>).
+ * The use of programs such as `debootstrap` and `cdebootstrap` helps with this process (see <<_chroot_system>>).
  * Use installers of OSs under the full system emulation.
 - Run a program under a virtualized environment.
  * http://en.wikipedia.org/wiki/Chroot[chroot] provides basic virtualized environment enough to compile programs, run console applications, and run daemons in it.
@@ -1932,6 +1972,6 @@
 
 http://en.wikipedia.org/wiki/VirtualBox[VirtualBox] comes with http://en.wikipedia.org/wiki/Qt_(toolkit)[Qt] GUI tools and quite intuitive.  Its GUI and command line tools are explained in http://www.virtualbox.org/manual/UserManual.html[VirtualBox User Manual] and http://download.virtualbox.org/virtualbox/UserManual.pdf[VirtualBox User Manual (PDF)].
 
-TIP: Running other GNU/Linux distributions such as http://www.ubuntu.com/[Ubuntu] and http://fedoraproject.org/[Fedra] under http://en.wikipedia.org/wiki/Virtualization[virtualization] is a great way to learn configuration tips.  Other proprietary OSs may be run nicely under this GNU/Linux http://en.wikipedia.org/wiki/Virtualization[virtualization], too.
+TIP: Running other GNU/Linux distributions such as http://www.ubuntu.com/[Ubuntu] and http://fedoraproject.org/[Fedora] under http://en.wikipedia.org/wiki/Virtualization[virtualization] is a great way to learn configuration tips.  Other proprietary OSs may be run nicely under this GNU/Linux http://en.wikipedia.org/wiki/Virtualization[virtualization], too.
 
 
