Mounting a Flash Filesystem - Revision history

Bserrano at 15:07, 11 April 2014

2014-04-11T15:07:07Z

Bserrano at 21:20, 6 March 2014

2014-03-06T21:20:01Z

Bserrano at 20:55, 6 March 2014

2014-03-06T20:55:19Z

Mdean: Reverted edits by Mgloff (talk) to last revision by Mwelling

2014-01-03T18:26:30Z

Reverted edits by Mgloff (talk) to last revision by Mwelling

Mgloff at 23:38, 20 December 2013

2013-12-20T23:38:55Z

Mgloff at 23:35, 20 December 2013

2013-12-20T23:35:38Z

Mwelling: This page is done.

2013-12-20T17:00:26Z

This page is done.

Mdean: Assigned MW to review this.

2013-12-17T03:26:55Z

Assigned MW to review this.

Mdean: Approved for Final Draft

2013-12-05T05:01:41Z

Approved for Final Draft

Mdean: /* Determining the Device Node Assigned to the Flash Device */ Fixed typo.

2013-12-05T04:57:57Z

‎Determining the Device Node Assigned to the Flash Device: Fixed typo.

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-{{todo| SEOKWTODO (11.27.13-12:15->KY+);(12.04.13-23:00->MD+);(12.20.13-11:00->MW+);(03.06.14-14:55->BS-)|Klint Youngmeyer|project=oe 4,oe 5,ky,SEOKWTODO,md,mw,bs}}
+{{todo| SEOKWREV (11.27.13-12:15->KY+);(12.04.13-23:00->MD+);(12.20.13-11:00->MW+);(03.06.14-14:55->BS-);(04.11.14-10:05->BS+)|Klint Youngmeyer|project=oe 4,oe 5,ky,SEOKWREV,md,mw,bs}}
 In order to use a flash filesystem on an EMAC OE system, it must be mounted first.
 __TOC__

← Older revision		Revision as of 21:20, 6 March 2014
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−	{{todo\| SEOKWTODO (11.27.13-12:15->KY+);(12.04.13-23:00->MD+);(12.20.13-11:00->MW+);(03.06.14-14:55->BS+)\|Klint Youngmeyer\|project=oe 4,oe 5,ky,SEOKWTODO,md,mw,bs}}	+	{{todo\| SEOKWTODO (11.27.13-12:15->KY+);(12.04.13-23:00->MD+);(12.20.13-11:00->MW+);(03.06.14-14:55->BS-)\|Klint Youngmeyer\|project=oe 4,oe 5,ky,SEOKWTODO,md,mw,bs}}

	In order to use a flash filesystem on an EMAC OE system, it must be mounted first.		In order to use a flash filesystem on an EMAC OE system, it must be mounted first.

← Older revision		Revision as of 20:55, 6 March 2014
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−	{{todo\| ~~Complete~~ (11.27.13-12:15->KY+);(12.04.13-23:00->MD+);(12.20.13-11:00->MW+)\|Klint Youngmeyer\|project=oe 4,oe 5,ky,~~Complete~~,md,mw}}	+	{{todo\| SEOKWTODO (11.27.13-12:15->KY+);(12.04.13-23:00->MD+);(12.20.13-11:00->MW+);(03.06.14-14:55->BS+)\|Klint Youngmeyer\|project=oe 4,oe 5,ky,SEOKWTODO,md,mw,bs}}

	In order to use a flash filesystem on an EMAC OE system, it must be mounted first.		In order to use a flash filesystem on an EMAC OE system, it must be mounted first.

@@ Line 10: / Line 10: @@
 * Mount the device.
 </cl>
+<br clear=all>
-{{mbox  | type=notice | style = margin-botton: 1em; | text='''NOTE''': You '''must''' have <code>root</code> permissions to perform some of the following steps. Use the <code>su</code> command to switch to the root user. The filesystem will also need to be mounted read/write in order to create the directory mentioned below. See [[Quick_Reference#Making_Changes_To_The_Target_Machine's_Filesystem | Remounting a Filesystem]] }}
+{{mbox  | type=notice | text='''NOTE''': You '''must''' have <code>root</code> permissions to perform some of the following steps.  Make sure you are logged in as the <code>root</code> user prior to performing the following steps.  The <code>su</code> command can be useful for this.  The filesystem will also need to be mounted read/write in order to create the directory mentioned below.  See the section regarding remounting the root filesystem as read/write (above) to see how to do this.}}
+<br clear=all>
 ==Determining the Device Node Assigned to the Flash Device==
-The easiest way to determine which device node is assigned to a particular flash device is to inspect the output of the ''dmesg'' command shortly after the device has been connected to your machine.
+The easiest way to determine which device node is assigned to a particular flash device is to inspect the output of the ''dmesg'' command shortly after the device has been connected to your machine.  Follow these steps to do so:
 <cl>
 . Insert the SD, CF or microSD card or plug in the USB flash device to your EMAC OE machine.
 * Wait a few seconds for the device to settle and be recognized by the OS.
-* Run this command at a shell on your EMAC OE machine:
+* Run this command at a shell on your EMAC OE machine: <br clear=all> <syntaxhighlight lang=console>root@emac-oe:~# dmesg | tail -n 15</syntaxhighlight>
 * Inspect the output. The output should look similar to the following:
-<syntaxhighlight lang=console highlight=14>
+<syntaxhighlight lang=console>
 usb 2-2: new full speed USB device using at91_ohci and address 2
 usb 2-2: not running at top speed; connect to a high speed hub
@@ Line 42: / Line 39: @@
 </syntaxhighlight>
-The highlighted line shows that the root device node for the flash device is <code>sda</code> containing one partition <code>sda1</code>.
+Inside square brackets, we see <code>sda</code>.  This is the root device node assigned to our flash device.
 </cl>
 ==Determine Which Partition to Mount==
-For this example, there is only one partition. It is possible that the flash device contains up to 4 ''primary partitions''. If there are multiple partitions, choose the partition that contains the data that needs to be accessed. Repeat the steps below to mount the additional partitions if necessary. A partition with the number 5 (sda5) indicates an ''extended partition''.
+On a line by itself, we see:
 ==Determine Where to Mount the Device==
-Now that we know what partition we are going to mount, we need to determine where to mount it. The <code>/mnt</code> directory is typically used for the root mount point.
+Now that we know what device node we are going to mount, we need to determine where to mount it.  The <code>/mnt</code> directory is typically used for this (<code>mnt</code> is short for ''mount'').
 Create a directory to use for the mountpoint:
- root@emac-oe:~# mkdir /mnt/myflash
+<syntaxhighlight lang=console>root@emac-oe:~# mkdir /mnt/myflash</syntaxhighlight>
-Any directory on the filesystem can be used as a mount point provided that the required permissions are obtained. If the directory used as the mount point contains files, they will be hidden when the flash device is mounted.
+Alternatively, you can pick another place in the filesystem to use.  Just make sure you have permission to create a directory in that location.  If the directory contains files, it will still be used as the mountpoint when the ''mount'' command is issued; however, the files contained in the directory will be hidden for as long as the directory is in use as a mountpoint.  This could create a great deal of confusion, so beware this potential pitfall.
-{{mbox | type=notice | text='''NOTE''' The ''mountpoint'' is the directory which is used to host the root of the filesystem located on the mounted partition.  In other words, if this were a machine running an operating system from Microsoft, the ''mountpoint'' would be a drive letter such as <code>D:</code> or <code>Z:</code>.  In Linux (and Unix), there are no drive letters.  Directories are used instead.}}
+<br clear=all>{{mbox | type=notice | text='''NOTE''' The ''mountpoint'' (where a device is mounted) is the directory which is used to host the root of the filesystem located on the partition.  In other words, if this were a machine running an operating system from Microsoft, the ''mountpoint'' would be a drive letter such as <code>D:</code> or <code>Z:</code>.  In Linux (and Unix), there are no drive letters.  Directories are used instead.  Beneficially, using directories instead of drive letters makes things more consistent (and therefore simpler) from a programming standpoint.}}<br clear=all>
 ==Mount the Device==
-Now that ''sda1'' has been determined to be the partition to mount and ''/mnt/myflash'' has been created to be used as the mountpoint, the flash device can be mounted with the following command:
+Now that ''sda1'' has been determined to be the partition to mount and ''/mnt/myflash'' has been created to be used as the mountpoint, we can mount our flash device with the following command:
- root@emac-oe:~# mount /dev/sda1 /mnt/myflash
+<syntaxhighlight lang=console>root@emac-oe:~# mount /dev/sda1 /mnt/myflash</syntaxhighlight>
 If no message is returned from the above command, then it succeeded.  To verify this, try the following command
- root@emac-oe:~# mount | grep sda1
+<syntaxhighlight lang=console>root@emac-oe:~# mount | grep sda1</syntaxhighlight>
-{{mbox | type=notice | text='''NOTE''': If the device node was something other than <code>sda1</code>, then replace <code>sda1</code> in the command above with the correct device node for the flash device in the ''Determine Which Partition to Mount'' section above.}}
+You should see your device listed in the output of the above command.  If it is listed more than once, it may have been mounted automatically by the OS.  If so, inspection of the output should show you where it was mounted.
 ==Unmounting the Filesystem After Use==
-After you are finished using the flash device, you may wish to unmount it (similar to "Safely Removing" a device on other operating systems). The ''umount'' command is used for this purpose. Make sure there are no terminal windows open accessing any files or directories on the mounted filesystem before unmounting.
+After you are finished using the flash device, you may wish to unmount it (similar to "Safely Removing" a device on other operating systems).  The ''umount'' command is used for this purpose.
-Continuing on with the example above, the device would be unmounted with the following command:
+Continuing on with the example above, the device mounted above would be unmounted with the following command:
- root@emac-oe:~# umount /mnt/myflash
+<syntaxhighlight lang=console>root@emac-oe:~# umount /mnt/myflash</syntaxhighlight>
 If it was automounted elsewhere, it will also need to be unmounted from that mountpoint before it will be safe to remove the device.  For instance, if the automounter mounted it on ''/media/sda1'', then issue the following command:
- root@emac-oe:~# umount /media/sda1
+<syntaxhighlight lang=console>root@emac-oe:~# umount /media/sda1</syntaxhighlight>
-{{mbox | typ=notice | text='''TIP''': The <code>sync</code> command can also be handy for ensuring data written to a device is flushed to disk prior to performing some other activity with the device.}}
+<br clear=all>{{mbox | typ=notice | text='''TIP''': The <code>sync</code> command can also be handy for ensuring data written to a device is flushed to disk prior to performing some other activity with the device.}}<br clear=all>

@@ Line 56: / Line 56: @@
 Any directory on the filesystem can be used as a mount point provided that the required permissions are obtained. If the directory used as the mount point contains files, they will be hidden when the flash device is mounted.
-<br clear=all>{{mbox | type=notice | text='''NOTE''' The ''mountpoint'' is the directory which is used to host the root of the filesystem located on the mounted partition.  In other words, if this were a machine running an operating system from Microsoft, the ''mountpoint'' would be a drive letter such as <code>D:</code> or <code>Z:</code>.  In Linux (and Unix), there are no drive letters.  Directories are used instead.  Beneficially, using directories instead of drive letters makes things more consistent (and therefore simpler) from a programming standpoint.}}<br clear=all>
+{{mbox | type=notice | text='''NOTE''' The ''mountpoint'' is the directory which is used to host the root of the filesystem located on the mounted partition.  In other words, if this were a machine running an operating system from Microsoft, the ''mountpoint'' would be a drive letter such as <code>D:</code> or <code>Z:</code>.  In Linux (and Unix), there are no drive letters.  Directories are used instead.}}
 ==Mount the Device==
@@ Line 81: / Line 81: @@
   root@emac-oe:~# umount /media/sda1
-<br clear=all>{{mbox | typ=notice | text='''TIP''': The <code>sync</code> command can also be handy for ensuring data written to a device is flushed to disk prior to performing some other activity with the device.}}
+{{mbox | typ=notice | text='''TIP''': The <code>sync</code> command can also be handy for ensuring data written to a device is flushed to disk prior to performing some other activity with the device.}}

← Older revision		Revision as of 17:00, 20 December 2013
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−	{{todo\| ~~FinalDraft~~ (11.27.13-12:15->KY+);(12.04.13-23:00->MD+)\|Klint Youngmeyer\|project=oe 4,oe 5,ky,~~FinalDraft~~,md,mw}}	+	{{todo\| Complete (11.27.13-12:15->KY+);(12.04.13-23:00->MD+);(12.20.13-11:00->MW+)\|Klint Youngmeyer\|project=oe 4,oe 5,ky,Complete,md,mw}}

	In order to use a flash filesystem on an EMAC OE system, it must be mounted first.		In order to use a flash filesystem on an EMAC OE system, it must be mounted first.

← Older revision		Revision as of 03:26, 17 December 2013
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−	{{todo\| FinalDraft (11.27.13-12:15->KY+);(12.04.13-23:00->MD+)\|Klint Youngmeyer\|project=oe 4,oe 5,ky,FinalDraft,md}}	+	{{todo\| FinalDraft (11.27.13-12:15->KY+);(12.04.13-23:00->MD+)\|Klint Youngmeyer\|project=oe 4,oe 5,ky,FinalDraft,md,mw}}

	In order to use a flash filesystem on an EMAC OE system, it must be mounted first.		In order to use a flash filesystem on an EMAC OE system, it must be mounted first.

← Older revision		Revision as of 05:01, 5 December 2013
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−	{{todo\| ~~Review~~ (11.27.13-12:15->KY+)\|Klint Youngmeyer\|project=oe 4,oe 5,ky,~~review~~,md}}	+	{{todo\| FinalDraft (11.27.13-12:15->KY+);(12.04.13-23:00->MD+)\|Klint Youngmeyer\|project=oe 4,oe 5,ky,FinalDraft,md}}

	In order to use a flash filesystem on an EMAC OE system, it must be mounted first.		In order to use a flash filesystem on an EMAC OE system, it must be mounted first.