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Lenovo Thinkpad T400s Samsung SSD Trim Enablement

Samsung SSD Trim Enablement

Destilled howto from these sites
http://forums.lenovo.com/t5/T400-T500-and-newer-T-series/TRIM-firmware-for-the-128-GB-Samsung-SSD/td-p/237421
http://thinkpad-forum.de/threads/102942-TRIM-Firmware-für-Lenovo-gelabelte-Samsung-SSD-(128-GB-Typ-MMCRE28G8MXP-Version-VBM1EL1Q)

Secure Erase

From http://www.thomas-krenn.com/de/wiki/SSD_Secure_Erase

  • Boot from a live CD
  • hdparm -I /dev/sdb
    • Check for support. If the drive is frozen, hot-unplug und plug it
  • hdparm --user-master u --security-set-pass Eins /dev/sdb
  • time hdparm --user-master u --security-erase Eins /dev/sdb
    security_password="Eins"

Alignment

http://www.ocztechnologyforum.com/forum/showthread.php?54379-Linux-Tips-tweaks-and-alignment&p=373226&viewfull=1#post373226

  • fdisk -H 32 -S 32 /dev/sda
    • o
    • n
    • p
    • 1
    • 2
    • +100G
    • t
    • 83
    • w

Create DOS-BOOT-USB-STICK using ubuntu - Not working!

Make bootable USB-Stick (Ubuntu Linux)

  • Insert USB-Stick
  • Find out device:
    • df
    • -> it's /dev/sdc for me
  • sudo gparted /dev/sdc
    • Partition -> Create -> Fat32
    • Partiton -> Manage flags -> "boot"
  • sudo apt-get p7zip-full
  • Download http://unetbootin.sourceforge.net/#install
  • Make the file executable and launch it
    • Select FreeDOS
    • Select your USB-Stick
    • Click "OK"

 

 

 

Old Stuff / Recherche

 

http://thinkpad-forum.de/threads/102942-TRIM-Firmware-für-Lenovo-gelabelte-Samsung-SSD-(128-GB-Typ-MMCRE28G8MXP-Version-VBM1EL1Q)

MY DISK:

  • SAMSUNG MMCRE28G8MXP-0VBL1
  • Firmware Revision:  VBM1DL1Q
  • Target: VBM19C1Q? (TRIM supported)

generic stuff check trim / alignment

bluefrog

  • I just confirmed that Trim can in fact be enabled on these drives.

    I have Lenovo 128gig Samsung SSD  VBM1EL1Q

     

    go here: http://forum.notebookreview.com/alienware/444979-alienware-owners-samsung-pm800-ssd-trim-now-availab...

     

    Get the .rar that "contains everthing we need to enable trim" uncompress and put it on a bootable usb.

     

    Backup your drive, everything must be erased.  Use a partition backup routine so you can just restore it.  (I used Windows 7 backup)

     

    Go into bios and change your SATA setting from "AHCI" to "compatible".  Remove the SSD.  Boot from your USB. (Hit F12 on startup, select to boot from USB drive)

     

    ***  One additional step to verify, optional, but would recommend it...  

    Boot to your USB drive with the SSD still plugged in.  Run maindiag.exe to verify that it sees your SSD in this configuration.  It will populate the make/serial/firmware fields with the Lenovo info, just reassuring you that it is seeing the correct drive and setup correctly to flash.  Then shut down, pull the SSD out and continue below.  Do not try to flash it with the model/serial/firmware numbers showing, see note below *****

     

    When you get the C:\ prompt, insert your SSD drive into you laptop (hot plug it in).  <-- Important, if you boot with the SSD in, maindiag.exe will detect it as Lenovo and will only half flash it, don't go there, recoverable but ugly.  If you hotplug it in after boot to c:\ , maindiag.exe will not display the drive version numbers (lines will have no values) just run flash sequence below and it will work and report successful.  If you want to verify the drive it is seeing, do the optional step above.

     

    Run maindiag.exe select number 2, then number 1, then number 4.  <--Important that you do all three steps, in this order.

     

    You will see a "Success" message after each step.

     

    Reinsert hard drive, reboot, change bios setting back to ahci, reboot, restore image from backup from whatever boot media you created during backup process.  (Again, I used Windows Backup and Windows 7 Installer -->  choose recovery and selected my backup file.)

     

    Run Crystal Disk info to reveal you have now enabled TRIM,(AAM) Acoustics Management, (NCQ)Native Command Queuing.

    Windows experience went from 5.9 to 7.2 and your firmware is now VBM19C1Q

     

    Yeah! 



    http://forum.notebookreview.com/alienware/444979-alienware-owners-samsung-pm800-ssd-trim-now-available.html

  • Make sure you have your bios SATA setting to "Compatible" not AHCI

    Second, boot from USB with hard drive in, run maindiag.exe, should populate with your model, firmware, etc.

     

    If it does populate the make/model/firmware correctly, shutdown, reboot to USB with your hard drive out.

    When it boots to c:\, insert your hard drive.  Run maindiag.exe again.

     

    This time, the make, model, serial, etc. lines will appear, but will be blank.  It will not show your versions.  

     

    (This is the hole in the flash routine, it is seeing your drive, but cannot tell the firmware/model, therefore it flashes it.  If you try to flash it while it can read your firmware, it will only flash the main firmware, not the initialize firmware because it will check the firmware version and refuse to flash it.)

     

    Proceed with the 2,1,4 routine.  It will tell you success or fail after each one.

     

    If you run maindiag.exe with no hard drive in at all, you will not see the make,model,firmware lines at all, it will just say no drive found and return you to the command prompt.

     

    The SATA connector is hot-pluggable by default, that is part of the spec for SATA.  So there is no way to turn hot plug on or off in the bios, it is up to the OS to utilize the spec correctly, assign a drive letter, etc., and DOS does not do this which is why it cannot pull the firmware version after the hotplug, but the flash routine still finds the drive.

  • Another success with Blue_Frogs method. Thank you very much.

    However some notes to your HowTo.

    At first I tried to plug-in the SSD when I got the C:smileyembarrassed: prompt. However maindiag still printed out the version information. I had to plug it out type "maindiag" and then hit Return and at the same time plug in the SSD.

    Maybe this has something todo with the DOS version on the USB stick or some vodoo magic I don't know.

     

    Also I had to hotplug the SSD after running each step (2, 1, 4) otherwise maindiag would throw an error message like "device not ready" when I tried to proceed with the next step. However except for these minor issues everything worked fine.

  • Thanks guys.  I successfully upgraded my firmware at well.  I had a little trouble getting the blank versions to show up.  I had to:

     

    1. Boot with the drive in.

    2. Start maindiag

    3. Unplug drive

    4. Plug Drive back in.

    5. Use option 4.

  • I was having issues flashing my drive in my T400s. All worked as described until I hot plugged the drive. As soon as the drive was plugged in, maindiag recognized it as a Lenovo branded firmware drive. After rereading the previous post, I realized that some on the board had enabled the BIOS SSD Wipe drive selctor option. I had not enabled this option so I went ahead and enabled the BIOS functionality with the Lenovo ISO flashing image. I then gave it one last try to flash the drive with the new firmware and I was able to flash the drive as described.

     

    I now have a TRIM enable SSD!!!!


  • Ok everyone, here is how to flash for those that cannot be done with hotplug, as the serial number is always read correctly.

    THIS REQUIRES THAT HOTPLUGGING YOUR DRIVE DOES NOT CAUSE YOUR MACHINE TO REBOOT! 

    Ok, let me repeat, if you boot your machine from USB with your SSD out of the machine and plug in your hard drive and your machine does an automatic reboot, do not proceed, you will brick your drive until you get another machine to fix this.  If your machine does not automatically reboot when plugging in the SSD at a DOS prompt, then you can proceed.

    1.  Boot to your usb with the drive in the laptop. (all other drives out and Compatibility set in bios)
        Check your bios settings and make sure you reenabled AHCI mode.  Otherwise in compatibility mode, windows will not be able to load the filesystem driver and give you the exact error you are describing.

    2.  Run maindiag.exe, you will see the model/serial/firmware populated.  (this is ok this time)

    3.  Choose Initialize Firmware (2) then Main Firmware (1), then (Q) to quit.  (These steps will fail and that is ok, you just mismatched your drive and confused it which is what we want)

    4.  Attempt reboot - your machine should not boot, not even from the thumb drive.  You will get a LOCK symbol in the upper left asking for a password.  If you get this, fantastic, that is what you want!  Do not try to type passwords there to unlock it, I don't know how many attempts you get until it locks up.

    5.  Turn off laptop and pull SSD hard drive out of laptop.

    6.  Reboot to USB drive (with no hard drive installed)

    7.  After you get to DOS prompt,  hotplug in your SSD hard drive.

    8.  Run maindiag (model/serial/firmware will be blank this time) and choose (2), (1), (4), (Q) 

    9.  Reboot to USB with SSD drive in and run maindiag, should see model/serial/firmware populated correctly. (VBM19C1Q)

    10.  Power off, change bios back to AHCI, restore system

    Let me know if this works for others.  I have seen it work on a few machines so far.

    -Blue_Frog

  • Boot to USB without the drive inserted.

    After you get to dos, insert the drive and run maindiag.exe

    Do the 2-1-4-Q sequence. 

    Drive will flash even though it is not recognized, that is exactly what you want.

  • Make sure your bios is in compatibility mode, not AHCI mode.

    Only time I have seen that error is when the BIOS is not set correctly.

  • Skeleton: Be aware that on Linux, the LVM and device-mapper layers are probably not passing discard requests to the hardware. Last I checked, these features were still under discussion but not implemented. So, you will only get automatic discard if you put your filesystem on a plain partition. There are some discard scripts that can help with this situation, but they only discard when you manually execute them, and they are a bit of a hack. They basically generate a large file to fill all free space, then ask the filesystem what blocks are occupied, then generate a manual discard list that is passed to the hdparm utility to perform ATA discard commands without the filesystem's participation. You had better make backups before trying something like this too! I have followed other Linux howtos to align my filesytems and to overprovision my Samsung SSD. I have had good performance so far, but have not been using VMs. I did a secure erase and then only partitioned about 100 out of 128 GB, leaving the rest for the drive firmware to use as spare space. I have only tried the discard scripts once, and am not sure I will bother again, but wait until the device-mapper layer can handle it itself.

  • http://forums.lenovo.com/t5/T400-T500-and-newer-T-series/TRIM-firmware-for-the-128-GB-Samsung-SSD/td-p/237421/page/7

     

other

  • To get the SSD Erase function in the BIOS you must run following update via CD.

    http://www-307.ibm.com/pc/support/site.wss/document.do?sitestyle=lenovo&lndocid=MIGR-68369

     

    Download the ISO, create CD, boot to CD and "Enable" the menu option in the BIOS. Reboot the laptop without the CD, hit "F2", go into "Security" and you will see the Erase SSD option. Not sure if this is the issue, but once I enabled the menu, I was able to flash the firmware as described.

  • thanks for the guide! worked for me:smileyhappy: just one note: after booting into c: and hotplugging, the Maindiag still showed the values of the ssd. I tried several times but never left the lines blank.

    so i just played risk and started with step 2 anyway. success. then took the drive out again and rebooted into c: again. hotplugged in and started maindiag again. and then the lines were blank! so i continued with step1. success. reboot again. (dont remember if i hotplugged again). anyway, did the last step (4). success.

    now i am copying my image back to the ssd:smileyhappy:

    thanks again!

     

  • Update: I tried a 3rd PC and it still only recognized the ssd while it booted with it plugged in but not when I hot swapped it.

    I also tried a totally different ssd and I get the same result. I even created a new usb stick to boot from.

    I have seen Blue_Frogs instructions on page 15 but I am afraid to try it out. I fear that since my ssd doesnt get recognized when I hot plug it in that I will make it useless and not be able to go further than step 7 in his instructions.
  •  

    I have been trying to flash my Samsung 128gb drive for my x301 for the past 2 days.  The first challenge was obtaining a bootable USB disk.  The HP utility worked but wouldn't accept my Dos 6.22 files.  Eventually I went real old school and used a USB floppy drive, booted MS-DOS 6.22, and then swapped the disk to the maindiag.exe files.

     

    My procedure is:

    1. Update BIOS to enable secure erase.

    2. Shutdown, remove SSD

    3. Boot MS-DOS 6.22

    4. Insert drive

    5. Run Maindiag

    6. Drive is recognized, i.e. Model, Serial, and Firmware fields are populated.

    7. Initialize Firmware.

    8. Long wait for ".    .     .     .      .     .     .      .     .      ."

    9. "Erase Fail" "Check System" "ATA command timed out"  Screen shot

    Following Blue-Frog's advice on Page 15 of this thread.

    10. Tried Updated MainFirmware with the same result.

    I was able to reboot and never got the locked password screen

    When I try to reimage the drive, Windows 7 wants me to repair the disk.  Clonezilla doesn't report any errors on the disk write, my rate in Clonezilla is a paltry 1.06 GB/min.

     

    Drive Sticker
     

    The windows system was asking for a repair disk because I didn't change the SATA bios setting back to AHCI.

    I can boot up again (whew).

  • Procedure on Linux

     

    * I created a DOS boot disk from a USB flashdrive ?using cfdisk to partition the drive (mark the primary partition bootable, FAT16), ms-sys -s to write the MBR, mkdosfs -F16 to format the the first partition, and sys F: within DosEmu to load a DOS environment into the partition.  (N.B.: qemu is not a good test for whether or not your USB stick works, as it's much less finicky than an actual BIOS.)

     

    * To get the firmware loading to work I had to plug in the SSD *after* I started the flashing software, otherwise the drive was being identified.  I did action 4 first, then 2 and 1.  I had to repeat this cycle of unplugging the disk, restarting the flashing software, then re-plugging the disk before actions 2 and 1.

     

    * hdparm -I /dev/sda indicates TRIM is enabled, and a test using hdparm --fibmap and hdparm --read-sector shows that TRIM is working.

     

    * I created a file with random data that filled the empty space in my drive (~40GB) and deleted it, using sync afterwards.  I then waited 30 minutes before running the bonnie++ benchmark. (Perhaps I should have just done an hdparm --trim-sector-ranges before restoring my disk ...?)

  • Reporting SUCCESS here using instructions from Lev.

     

    Updated firmware on two Samsung MMCRE28G8MXP-0VBL1 (from VBM1EL1Q to VBM19C1Q) using a HP 2530p EliteBook.

     

    Here are my steps, they are very similar to Lev's:

     

    1. Backup contents of SSD using Windows 7 Backup to an external USB HD
    2. Create Windows 7 Repair Disk
    3. Download firmware upgrade files from: http://forum.notebookreview.com/alienware/444979-alienware-owners-samsung-pm800-ssd-trim-now-availab...
    4. With SSD plugged in to the notebook
    5. Power up and change SATA mode to "IDE"
    6. Insert USB boot key (with unzipped contents of downloaded firmware upgrade files from step 3)
    7. Run maindiag.exe
    8. Unplug ONLY the power cable and then replug it (since the power and SATA cable is one unit, only slide the power portion of the cable off)
    9. - Select 2 -> Unplug ONLY the power cable and then replug it
    10. - Select 1 -> Unplug ONLY the power cable and then replug it
    11. - Select 4 -> Quit
    12. - Power down the notebook
    13. - Boot with Windows 7 repair disk and restore backup on external USB HD to the SSD.

     

    CrystalDiskInfo shows my SSD features: AAM, NCQ, TRIM

    Windows Experience Index score for Primary Hard Disk went from "5.9" to "7.2".

     

    Thanks Blue_Frog and Lev!

     

    Hopefully this helps others...

    Sam.

  • There is an package containing everything needed - VBM19C1Q firmware, Win 98 boot files, maindiag update utility and HP USB format tool.

    Download from Rapidshare or Hotfile or FileServe.

  •  

    I was able to complete the following on an HP 6910p. Thanks Blue_Frog!

     

    THIS REQUIRES THAT HOTPLUGGING YOUR DRIVE DOES NOT CAUSE YOUR MACHINE TO REBOOT!

    Ok, let me repeat, if you boot your machine from USB with your SSD out of the machine and plug in your hard drive and your machine does an automatic reboot, do not proceed, you will brick your drive until you get another machine to fix this. If your machine does not automatically reboot when plugging in the SSD at a DOS prompt, then you can proceed.

    1. Boot to your usb with the drive in the laptop. (all other drives out and Compatibility set in bios, on HP machine DISABLE SATA Native Mode)

     

    1. Run maindiag.exe, you will see the model/serial/firmware populated. (this is ok this time)
    2. Choose Initialize Firmware (2) then Main Firmware (1), then (Q) to quit. (These steps will fail and that is ok, you just mismatched your drive and confused it which is what we want)
    3. Turn off laptop and pull SSD hard drive out of laptop.
    4. Reboot to USB drive (with no hard drive installed)
    5. After you get to DOS prompt, hotplug in your SSD hard drive.
    6. Run maindiag (model/serial/firmware will be blank this time) and choose (2)(Q)
    7. Pull drive out with system on and hot plug again and
    8. Run maindiag (model/serial/firmware will be blank this time) and choose (1)(Q)
    9. Pull drive out with system on and hot plug again and
    10. Run maindiag (model/serial/firmware will be blank this time) and choose (4)(Q)
    11. Reboot to USB with SSD drive in and run maindiag, should see model/serial/firmware populated correctly. (VBM19C1Q)
    12. Power off, change bios back to AHCI, restore system

     

     

  • Also wanted to mention that before and after the firmware upgrade I was getting 5.9 in the WEI. 

    I decided to do a ATA Secure Erase, now my WEI jumped to 7.3.

     

    Instructions:

    https://ata.wiki.kernel.org/articles/a/t/a/ATA_Secure_Erase_936d.html

     

    I also then followed the "Four Steps to Optimize Your SSD.

    http://blog.tune-up.com/tips-and-tricks/four-steps-to-optimize-your-ssd/

    Thanks, Joe?

external sata

  • Finally!  Success using Blue Frog's method!

     

    For my device, my T410s would always reboot upon attempted hot swap of the SSD.

     

    I was able to successfully implement this solution by following these steps:

     

    1)  Backup SSD to USB HD using Clonezilla

    2)  Remove SSD and using a SATA micro adapter attach it to a desktop system's SATA primary drive

    3)  Folow Blue Frog's method by booting the system with the drive plugged in,

    4)  When system was at dos prompt, unplug the power to the SSD

    5)  start maindiag, plug power back on device

    6)  Follow option 2, upon completion remove power cable and then replace, then option 1, same as previous with power cable swap and then option 4.

     

    Please note that I tried rebooting the first time I attempted this because I selected option 2, then rebooted the system and at this point, the system hung while trying to detect the device.  This was a headache that I was only able to get around by plugging another drive in so that computer would pass BIOS, then unplugging and patching in the SSD.

     

    Anyway, have TRIM now, thanks to Blue Frog.

  • Success!

     

    Here is what I did:

     

    - Plug the SSD to your Desktop (Motherboard: P5B Deluxe)

    - Set the SATA mode to "Compatible"

    - Boot to the USB Drive

    - Run maindiag.exe

    - Unplug ONLY the power cable and then replug it

    - Select 2 -> Unplug the power cable and then replug it

    - Select 1 -> Unplug the power cable and then replug it

    - Select 4 -> Quit

     

    I think the clue is, only to remove the power cable. Otherwise the maindiag.exe recognizes

    the SSD. This is the way a "hotplug" works. If you plug in the SATA cable the system checks your disc.

    If you only remove the power, the system doesn't run this check.

     

    This also confirms why sometimes the hotplug without a micro SATA cable works and sometimes not.

    It's "random" if your system first plugin the power or the SATA.

     

    I hope this works for you!

     

     

    Quote from Wikipedia (the reboot cycle problem):

    As their standard interface, SATA controllers use the AHCI, allowing advanced features of SATA such as hotplug and native command queuing (NCQ). If AHCI is not enabled by the motherboard and chipset, SATA controllers typically operate in "IDE emulation" mode, which does not allow features of devices to be accessed if the ATA/IDE standard does not support them.

 Performance

  • I did a before and after secure erase test. 

     

    Before:

     

    Min Read Rate: 219 / Max Read Rate: 261 / Average Read Rate: 233

    Min Write Rate: 13 / Max Write Rate: 69 / Average Write Rate: 25

     

    After

     

    Min Read Rate: 218 / Max Read Rate: 236 / Average Read Rate: 229

    Min Write Rate:  138 / Max Write Rate: 189 / Average Write Rate: 171

     

    This is on a unformatted disk using the Disk Utility under Ubuntu.

     

    Model: ATA SAMSUNG MMCRE28G8MXP-0VBL1

    Firmware: VBM19CQ1

Diag

  • Ok, trim seems to work for me too

     

     

    ubuntu@ubuntu:/target$ sudo dd if=/dev/urandom of=tempfile count=100 bs=512k oflag=direct 
    100+0 records in
    100+0 records out
    52428800 bytes (52 MB) copied, 16.0289 s, 3.3 MB/s
    ubuntu@ubuntu:/target$ sudo hdparm --fibmap tempfile

    tempfile:
     filesystem blocksize 4096, begins at LBA 2048; assuming 512 byte sectors.
     byte_offset  begin_LBA    end_LBA    sectors
               0   28743680   28751871       8192
         4194304   28837888   28846079       8192
         8388608   28936192   28952575      16384
        16777216   29034496   29050879      16384
        25165824   29214720   29231103      16384
        33554432   29640704   29657087      16384
        41943040   29771776   29788159      16384
        50331648   29935616   29939711       4096
    ubuntu@ubuntu:/target$ sudo hdparm --read-sector 28743680 /dev/sda

    /dev/sda:
    reading sector 28743680: succeeded
    a3f7 b98b dee7 965b 2071 0b5c 7058 13bb
    6157 4145 d7b0 0eeb 2f20 8ba5 fcda 2d26
    7b72 4be2 bd58 d57a 412b 5c0b 087f f5d6
    7ccf e7b6 d1f2 be07 0092 fafc 3ebd 85f1
    cbd4 cece 0093 5e71 0082 114f 5293 79cb
    baab 43be c2d5 7060 bfd3 221f 9c91 39f7
    08ce d2ea 09e5 8dd5 70e7 16ac 486a 567e
    d503 2d99 05d7 a455 82bb 4f22 5d7d 727a
    2f40 fa7e 25b4 78a5 4202 b08a 33c6 5811
    286d 522c 51d5 bdfb 974f 69bc 5fe6 98dc
    0086 a5f7 d88e b72d 0e47 8da2 b796 8075
    e6da 18e6 f30f 293b ba56 6b72 2f32 7b4c
    92ff 1e9d 6f45 0d75 6ee5 b0dd a273 968d
    c787 95c9 ca2d 93bd fda0 3bba b0a1 072d
    26cd 32f1 a6da 9e35 5f98 2294 e480 e40a
    3710 0552 f324 4c4e 6fa4 2db6 a6cc e07b
    de24 a378 4b49 66e8 741d f885 ea55 b7b8
    00b7 a415 f7e9 30e7 2a41 17e7 fb25 ffc3
    5abb 21e8 2581 2d52 97e2 4b13 01d8 04d3
    dd75 7a87 8df8 9021 4aa4 ad83 a398 d308
    0c36 bc13 5612 97cd 6780 29a3 273b a5a2
    fef1 05f8 3166 1b0d 8fc2 7f26 0ab5 a4da
    1a1f fd6b 06da fe12 8c9e 3e0e 48dd 5fe9
    e941 0858 47b9 585f 4399 c830 31f4 1eb0
    6656 076a 23f9 c7e4 bb9a 13f3 edae cbaa
    9b92 8e77 ee7d 4408 13eb f644 01ff 34ae
    f51d 5446 c1ac b388 d755 3982 2f75 24d3
    4783 cf78 4852 4860 9c45 a8d6 4ce3 7180
    d207 acd4 1324 21f9 1276 c5c4 4c33 d5e7
    7dd3 a94b e2b0 beb2 dfa7 ff35 3fc3 004c
    3a0b 9b83 e7a4 01f3 33ac 2448 bdf7 4fd2
    2f52 8ee5 fa3f 882c d2a1 58e8 a4d4 8b58
    ubuntu@ubuntu:/target$ sudo rm tempfile 
    ubuntu@ubuntu:/target$ sudo sync
    ubuntu@ubuntu:/target$ sudo hdparm --read-sector 28743680 /dev/sda

    /dev/sda:
    reading sector 28743680: succeeded
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000
    0000 0000 0000 0000 0000 0000 0000 0000

    i.e., rereading discarded sectors yields zeroes. 
    I find it interesting that read performance goes down in the area that have been written:
    (The remaing 25% of the disk are free space)
    Before copying the files back with rsync it looked like this:

     
    And hdparm benchmark
    sudo hdparm -t /dev/sda

    /dev/sda:
     Timing buffered disk reads:  628 MB in  3.00 seconds = 209.11 MB/sec