Posts Tagged ‘Linux’

How to recover your data from a dead Acer Aspire Easystore Raid1

Friday, May 13th, 2011

The Acer Aspire Easystore NAS units come in a variety of versions.  The latest unit uses a windows OS, but the earlier versions used a dumbed down Linux OS.  The units are, if not especially cheap, at least low priced.  This article is about the earlier versions using the Linux OS and recounts how we recovered our data from a failed unit.

The problem with the Linux based Acer Aspire Easystore is that while the unit will happily allow drives to be replaced, if you lose the motherboard or the Ethernet port you are in serious trouble.   It surprisingly easy to suffer a catastrophic problem.  For example, if you upgrade the firmware from 2.0 to 2.5 your unit can stop responding.   Further you can lose the motherboard  for a variety of  other reasons – for example, they seem especially sensitive to minor DC power spikes.  If the dreaded red light indicating “unrecoverable software” lights up or the unit simply stops talking to the network, you will rapidly discover you  are essentially screwed. 

Acer’s maintenance support, seems excellent when you contact them.  They will happily replace the unit for you (in fact that is all they will do!) and even send out a technician to swap your old still working drives into the new unit.  Unfortunately that is when you discover you have a serious problem.

The replacement unit will not read the RAID array from the old drives – even if your drives are otherwise OK.  If you are lucky, it will recognise the user accounts – but it will not give you back access to your data.  Acer’s helpful response is that you must rebuild the array.  Do not under any circumstances do this or you will lose your data!

This is what you must do…

In our case we always use RAID 1 on low cost RAID systems.  This essentially gives 2 copies of each disk without co-dependence across multiple disks for data recovery.

Recovering your data from the Acer becomes quite simple in this situation.

What you will need:

A spare computer (a Windows desktop is fine) with:

  •  at least one spare SATA port,
  • a spare SATA cable, (or just unplug an existing drive from the desktop computer and use its cable),
  • a spare HD drive  in FAT32 or Linux disk format so it can be accessed easily under Linux (or other NAS on the network) with enough space to store the files you recover from your Acer Easystore drive(s)
  • a CD ROM. 

Either the on the same  machine, or another, you need a writable CD drive, a spare blank CD and an internet connection.

Now follow these steps:

Step 1  Assuming you do not have a way to write ISO formats onto a CD ROM go here and download the ISO writer:

http://isorecorder.alexfeinman.com/isorecorder.htm

Just double click to install it and once installed you merely right-click on an ISO image and choose “Copy image to CD”.

Step 2: Get a copy of the latest version of Knoppix Linux from here (or other Knoppix mirror).   I used Knoppix 6.4.4

http://www.mirrorservice.org/sites/ftp.uni-kl.de/pub/linux/knoppix/

You do want the ISO image and unless you are visually impaired you do NOT need the ADRIANE version.

Step 3.  Put your blank CD into your writable CD drive and right click on the ISO image you just downloaded.  Choose “copy image to CD”.  This will give you a bootable version of Knoppix Linux on a CD ROM.

Step 4.  Turn off and open up your spare desktop computer and plug the first RAID1 drive from your dead Acer Aspire Easystore into the SATA data cable and the SATA power cable and plug the other end of the SATA data cable into a spare SATA port on the motherboard (or SATA sub-board).  Note the number written on the motherboard this will help you find the drive later.  You only need to plug in one drive from each RAID1 pair.  The drives are arranged in pairs making one volume each in the easystore – so the top two are one volume and the bottom two are another volume.  You want one drive from each volume.  We will just do one volume in this sequence, and you should repeat the following steps for the second volume after completing the first.

Step 5.  Turn on the computer and if it does not already boot from a CD ROM, trigger the BIOS setup on startup and change the boot order so that it boots from a CD ROM first.  Save and exit and allow the computer boot up.

Step 6.  Once Linux has started (you may have some minor config steps to work through), click on the little filing cabinet in the bottom left hand corner of your screen.  This will show you the mounted devices.  If your machine also has NTFS drives in it or even an existing RAID array in it there will be some drives marked OS which you will not be able to access.  Ignore these.  Your FAT32 drives and your Acer EasyStore Raid1 drive should be visible.  The mounted Acer drive will show as something like “sdc4″, where the “sdc” part might be sda, sdb, sdc, etc.  The number refers to the partition on the drive that could be read.  This will not have your data in it – so don;t get excited just yet.

Step 7.  In the bottom left hand corner of your screen, beside the filing cabinet icon is the Knoppix logo.  This is the equivalent of the windows “start menu”.  Click on this and from “preferences” choose “GParted”.  Let this do its stuff and when it has finished opening select the GParted menu, and from that the “Devices” submenu.  From this look for and select your Acer drive.  In my case it was on /dev/sdc -  yours may be different – but will be the one that was showing the “4″ in its name when you looked in the file system display.

Step 8.  After GParted has scanned it, you will notice this has 4 partitions.  The Linux swap and the system – both of which will be mounted and then two others – which will not be mounted.  The big one has your data, and the little one is just some spare space.  The big one will probably have a “2″ in its name.  In my case it was “sdc2″.  It will also be showing the file system type – probably “ext2″.  Note both the name (eg. sdc2) and the file system (eg “ext2″) – you will need them in a second.

Step 9.  Select this line by left clicking on on it and then right click to bring up the context menu.  From the context menu that displays choose “Manage Flags”.

Step 10.  In the “manage flags”  window that opens tick the “Raid” flag.  Then open the “Manage Flags” menu again and untick the “Raid” flag.  Close GParted.

Step11. From the “start menu” in the lower left hand corner of your screen choose “Accessories / Root Terminal”. 

Step 12.  When the console window opens type the following:

mount   /dev/sdc2   /media/sdc2 -oro -text2

NOTE:  change the “sdc2″ to the device name (and partition number) you saw in GParted earlier and the  “ext2″ file system type to the one you saw there as well.  It will most likely be ext2, but it might be ext3.   You have just mounted your lost data as “/media/sdc2″  – or whatever sd you entered above.

Step 13.  Click on the filing cabinet icon in the bottom left of the screen and in the address bar enter (adjusted appropriately for your device name):

/media/sdc2/

Your lost files should now be visible. 

Step 14:  Copy your lost files to your spare drive or other network store.   The Acer drive was opened in read-only mode by the mount command so you will can only copy or read them.

If you have two RAID1 volumes in your Acer EasyStore you should repeat all the steps  from step 4 for the second volume as well.

Good luck!  Feel free to drop me an email (or a comment here) if you have a question.  You can also rebuild a RAID5 array in a similar fashion – but it is a little more complex than the process for RAID1 recovery.