info before purchase

[lorenzoz]

Hi all, this is my first post on this forum.
I'd like to buy this board and install debian as OS, but I have few questions.

With the latest release, v4, is openvpn working correctly?
I don't understand how SATA connector works. I need to plug a cable near the port and also one in the external HD?
I have a 9V - 0.85A charger, it's enough? I need only Ethernet, SD and USB/sata.
SSH works out of the box?

Thank you for your help.

[XFer]

Hi, welcome.

Waiting for others to chime in, here's what I know:

I don't understand how SATA connector works. I need to plug a cable near the port and also one in the external HD?

The SATA connector is just like on a PC board: you need an ordinary SATA cable plugged on the board at one end and on the drive at the other end.
Then you have to provide power to the drive. The board has a 5V female connector from which you can power a low-power SATA drive (like a SSD or a 2.5" 5400rpm HDD), with a custom cable; you'll have to source it out or build yourself.
I'm not sure the board can provide enough power for a 7200rpm 2.5" drive, for example: if you need such a drive, you may want to power it externally.

I have a 9V - 0.85A charger, it's enough? I need only Ethernet, SD and USB/sata.

It is enough for the board, but it depends on the USB devices you attach to the board.
For example, A20 board + USB drive + SATA drive may require a beefier power brick.

SSH works out of the box?

Yes, if the Ethernet port is correctly configured for your network.
I'd suggest to mount the microSD on a Linux box first, mount r/w the second partition of the card (which is the ext4 root filesystem) and see if /etc/network/interfaces is OK for you, before booting the board.

By the way, since you mention SATA: the board will NOT boot from SATA as is (only boots from the microSD card or the onboard flash with Android, if you purchased that variant).
A user of the forum found a way to boot from SATA, if needed you may want to look for that thread.

Fernando

[lorenzoz]

The SATA connector is just like on a PC board: you need an ordinary SATA cable plugged on the board at one end and on the drive at the other end.
Then you have to provide power to the drive. The board has a 5V female connector from which you can power a low-power SATA drive (like a SSD or a 2.5" 5400rpm HDD), with a custom cable; you'll have to source it out or build yourself.
I'm not sure the board can provide enough power for a 7200rpm 2.5" drive, for example: if you need such a drive, you may want to power it externally.

The HD is a 1TB caviar blue 3,5" 7200rpm, so I need external power.

It is enough for the board, but it depends on the USB devices you attach to the board.
For example, A20 board + USB drive + SATA drive may require a beefier power brick.

Ok, but my SATA/USB drive will have his own power.

Yes, if the Ethernet port is correctly configured for your network.
I'd suggest to mount the microSD on a Linux box first, mount r/w the second partition of the card (which is the ext4 root filesystem) and see if /etc/network/interfaces is OK for you, before booting the board.

Oh thank you.

By the way, since you mention SATA: the board will NOT boot from SATA as is (only boots from the microSD card or the onboard flash with Android, if you purchased that variant).

Mmm, I can't boot from SDHC card? (not micro??)

A user of the forum found a way to boot from SATA, if needed you may want to look for that thread.

Find it.

[XFer]

It is enough for the board, but it depends on the USB devices you attach to the board.
For example, A20 board + USB drive + SATA drive may require a beefier power brick.

Ok, but my SATA/USB drive will have his own power.

Then you're OK. The board itself does not use much power; under full load (without external peripherals), it draws about 300 mA at 9V.

Mmm, I can't boot from SDHC card? (not micro??)

No, you can't, sorry. The (regular) SD slot is not bootable.

Fernando

[hnb2907]

Hi,

To answer your question about booting from SATA.  It's a while since I did this, with the brilliant help of other users on the forum.

Using my laptop running debian:  The micro-sd card was built with the olimex debian image v3.  I then built the same image on the SATA disk /dev/sda.  I created a 3rd partiton on sda for swap.  I then resized the root partition using gparted (in my case sda2) to use the remaining space on the SATA disk.

There are some instruction on here (check this thread https://www.olimex.com/forum/index.php?topic=1756.0), which explain how to create an initramfs and modify the bootloader.  The bootloader needs to be changed to boot from /dev/sda2 instead of /dev/mmcblk0p2
This must be installed on the micro-sd card.  The initramfs contains a kernel with the SATA driver module. 

Next, I made the changes discussed here https://www.olimex.com/forum/index.php?topic=1757.0.  I noticed that normally the A20 would run with a loadavg of 1.00.  I don't use USB-on-the-go, so the changes here are ok for me.

Lastly, I transferred the micro-sd into the A20, and connected the SATA.

The A20 first loads the bootloader from the micro-sd, and starts the kernel/initramfs.  At this time the SATA kernel module is loaded.  It can now continue to mount and boot the root partition at /dev/sda2 (i.e. SATA).  The second partition on the micro-sd card isn't used.


The A20 works perfectly, and is always switched on and running debian.  I only use ethernet to connect to it (samba/cifs and ssh).  I have quickly tried it with a usb mouse/keyboard and hdmi, it's brilliant!  It is running squeezeboxserver, apache, and will be running a smtp/pop webmail server soon. 

My A20 is powered at 12v, I believe my PSU is rated at 1.8A?  The SATA disk is powered directly from another suitable supply. 
I have run some linux stress tests on the hardware for many hours, and it was well behaved.
I have installed openvpn, but not yet configured or used it.

Hope that helps?
C.

[lorenzoz]

Thank you very much for your help.