fstab - custom

mmmmmm · #1 02-05-2013, 01:18 PM

I have an USB stick that I am using to install optional packages.
My problem is that sometime gets mounted as sda1 other times as sdb1.

This is a bit of a problem and I am trying to use the fstab.add feature of Merlin's version to mount the usb stick by UUID.

I've created a /jffs/config/fstab.add file, with the content below, but it does not seem to solve my problem. I suppose that my fstab.add file is not correct.

Code:

UUID=c6062286-5f15-4aaa-a142-580f9441ce92       /mnt/sda1       ext2    default,umask=077,gid=46         0      0

Beside this, I have another USB HDD with 2 partitions that also gets switched sometimes. Since I am using this HDD for my transmission download, this is quite problematic.

The UUIDs are:

Code:

admin@RT-N66U:/tmp/etc# blkid
/dev/sdc5: LABEL="SAMSUNG" UUID="01CCAADD89839CA0"
/dev/sdc1: LABEL="SAMSUNG" UUID="01CCAADD84C35570"
/dev/sdb1: UUID="c6062286-5f15-4aaa-a142-580f9441ce92"

Please advice.

mmmmmm · #2 02-06-2013, 01:26 AM

RMerlin,

please help!

I was not able to find any tutorial on how to properly use the custom config files so maybe the information here will turn out to be useful.

Thank you.

RMerlin · #3 02-06-2013, 01:41 AM

From the README:

Code:

The list of available config overrides:

* dnsmasq.conf
* vsftpd.conf
* pptpd.conf
* dhcp6s.conf
* hosts (for /etc/hosts)
* smb.conf
* minidlna.conf
* profile (shell profile, only profile.add suypported)
* upnp (for miniupnpd)
* radvd.conf
* fstab (only fstab supported, remember to create mount point
        through init-start first if it doesn't exist!)

There is no support for fstab.add, only a full replacement in the form of fstab. The reason is that the firmware does not create an fstab file, so there is nothing to append to.

mmmmmm · #4 02-06-2013, 01:45 AM

Quote:

Originally Posted by RMerlin

From the README:

Sorry about that. I read the readme but it was not that clear to me. My bad.
So the init-start is the way to go.

Thank you very much.

PS. I will post my finding once I get my setup working.

mmmmmm · #5 02-06-2013, 09:23 AM

Here is are my working scripts.

1. Get the UUIDs, current mount points, mount options of the connected USB devices:

Code:

# more /etc/mtab 
rootfs / rootfs rw 0 0
..............................
/dev/sda1 /tmp/mnt/sda1 ext2 rw,nodev,noatime 0 0
/dev/sdc1 /tmp/mnt/samsungp ufsd rw,nodev,noatime,nls=utf8,fmask=0,dmask=0,force 0 0
/dev/sdc5 /tmp/mnt/samsungo ufsd rw,nodev,noatime,nls=utf8,fmask=0,dmask=0,force 0 0

Code:

# blkid
/dev/sdc5: LABEL="SAMSUNG" UUID="01CCAADD89839CA0"
/dev/sdc1: LABEL="SAMSUNG" UUID="01CCAADD84C35570"
/dev/sda1: UUID="c6062286-5f15-4aaa-a142-580f9441ce92"

2. Create /jffs/scripts/init-start script:

Code:

# more /jffs/scripts/init-start 
#!/bin/sh

mkdir -p /tmp/mnt/sda1
echo  "UUID=c6062286-5f15-4aaa-a142-580f9441ce92        /tmp/mnt/sda1   ext2    rw,nodev,noatime        0       0" > /etc/fstab

mkdir -p /tmp/mnt/samsungo
echo  "UUID=01CCAADD89839CA0    /tmp/mnt/samsungo       ufsd    rw,nodev,noatime,nls=utf8,fmask=0,dmask=0,force 0       0" >> /etc/fstab

mkdir -p /tmp/mnt/samsungp
echo  "UUID=01CCAADD84C35570    /tmp/mnt/samsungp       ufsd    rw,nodev,noatime,nls=utf8,fmask=0,dmask=0,force 0       0" >> /etc/fstab

A reboot or a 'mount -a' should mount the drives as configured in the fstab file.

Beside the mount point switching issue, due to the fact that my HDD is NTFS formatted, I was experiencing some problems with transmission daemon not being able to find the download directory on the drive. I decided to delay the transmission daemon starting and I did the following:

1. Remove the x permission of the "/opt/etc/init.d/S88transmission" script.
2. Create /jffs/post-mount script:

Code:

# more /jffs/scripts/post-mount 
#!/bin/sh

sleep 1

transmission_file=`find /opt/etc/init.d/ -name *transmission*`
chmod 777 $transmission_file
$transmission_file start
chmod -x $transmission_file

Serpent · #6 02-08-2013, 06:25 AM

Nice work, mmmmmm!

But you can also use the fstab file from /jffs/config/, writting in it:

Code:

UUID=c6062286-5f15-4aaa-a142-580f9441ce92        /tmp/mnt/sda1   ext2    rw,nodev,noatime        0       0

UUID=01CCAADD89839CA0    /tmp/mnt/samsungo       ufsd    rw,nodev,noatime,nls=utf8,fmask=0,dmask=0,force 0       0

UUID=01CCAADD84C35570    /tmp/mnt/samsungp       ufsd    rw,nodev,noatime,nls=utf8,fmask=0,dmask=0,force 0       0

Leave in init-start only the mkdir lines and a "mount -a" line (maybe isn't required, but doesn't harm...).

I think it's worth to add also a swap space, using this line in init-start:

Code:

swapon UUID="swap_partition_UUID"

mmmmmm · #7 02-08-2013, 07:49 AM

Quote:

Originally Posted by Serpent

Nice work, mmmmmm!

But you can also use the fstab file from /jffs/config/, writting in it:

Leave in init-start only the mkdir lines and a "mount -a" line (maybe isn't required, but doesn't harm...).

I think it's worth to add also a swap space, using this line in init-start:

Code:

swapon UUID="swap_partition_UUID"

Thank you Serpent for sharing this.
I will do the changes as you suggested as it makes more sense.

I was not aware about the swapon instruction.
I think it is a nice feature. Is there a way to set the size of the swap?

Thanks again.

Serpent · #8 02-08-2013, 02:21 PM

Swap is indeed a very useful feature, especially when you are transferring large quantities of data, like me.

Usually you will use a whole partition of a hard disk for swapping. However, with the 2.6 Linux kernel, swap files are almost as fast as swap partitions, although I recommend using a swap partition.

The beginning(first cylinders) of a HDD is the best place for a swap space, on any OS. So you need to make a partition of 256 or 512 MB and leave it raw(not formated).
After that run the mkswap command:

Code:

mkswap /dev/sdx1

Find the UUID of that swap partition with blkid and test it:

Code:

swapon UUID="swap_partition_UUID"

Verify it with free command.

If is working add the command swapon to init-start.

huotg01 · #9 02-12-2013, 04:33 PM

Quote:

Originally Posted by Serpent

Swap is indeed a very useful feature, especially when you are transferring large quantities of data, like me.

This is something new for me (swapping in the context of a router). Could you give a little bit more information about how useful it is and why ?

Thanks,

GH

joegreat · #10 02-12-2013, 05:13 PM

Quote:

Originally Posted by huotg01

This is something new for me (swapping in the context of a router). Could you give a little bit more information about how useful it is and why ?

Hi,

Well, if you run Transmission (or any other memory heavy piece of software) then it can easily run out of memory.

Here my memory stat:

Code:

chief@RT-N66U:/# free
             total         used         free       shared      buffers
Mem:        239868       185944        53924            0        34884
-/+ buffers:             151060        88808
Swap:        64252         2160        62092

As you can see from above, ~2MB are swapped out to disk.

If the swap is not used, it does no harm.
But if the kernel runs out of memory, you better have a swap avaliable, or you run into serious troubles!

There are two situations, where Linux kernels get into panic mode: Out of memory and out of space on the root filesystem.

With kind regards
Joe