= Using smartctl with Samsung F4 !EcoGreen drives may result in data loss = '''WARNING: Do not use smartmontools with these drives! ''' '''This warning also applies to other tools (like hdparm) which use IDENTIFY DEVICE to obtain drive information.''' ---- 2010-11-24, updated 2010-11-30: Here are the details as reported by German c't magazine and [http://sourceforge.net/mailarchive/forum.php?thread_name=201011251136.03927.michael%40trunner.de&forum_name=smartmontools-support on our mailing list]: * Affected disk: SAMSUNG !SpinPoint F4 !EcoGreen 2TB {{{Device Model: SAMSUNG HD204UI}}}[[BR]] {{{Firmware Version: 1AQ10001}}} * Problem: If the system writes to this disk and {{{smartctl -a}}} (5.40) is used at the same time, write errors are reported and bad blocks appear on the disk. This was reported by a reader and could be reproduced in c't magazine lab on the following system: Windows 7 x64 Ultimate[[BR]] Core i3-560[[BR]] Intel H55 chipset[[BR]] SATA-AHCI-Driver: Intel Rapid Storage Technology (RST) 9.6 * It could also be reproduced under Linux (Fedora 14) if AHCI is enabled and the following commands are run in parallel: {{{ # badblocks -svw -b 4096 /dev/sdd 4000000 # smartctl -a /dev/sdd }}} * It could '''not''' be reproduced if the Intel H55 chipset is set to IDE mode. * It could also be reproduced on another system with an AMD chipset under Windows and drivers {{{msahci.sys}}} or {{{amdsata.sys}}}. * It could '''not''' be reproduced on the same AMD system and {{{amdsata.sys}}} driver with the following other disks: {{{SAMSUNG HD322GJ (F4)}}}[[BR]] {{{SAMSUNG HD103SJ (F3)}}}[[BR]] {{{SAMSUNG HD153WI (F3 EcoGreen)}}}[[BR]] {{{SAMSUNG HD642JJ (F1)}}}[[BR]] {{{SAMSUNG SP2504C (P120)}}}[[BR]] {{{WDC WD6400AAKS}}}[[BR]] {{{WDC WD10EADS}}} * It could also be reproduced on an system with Intel P45 chipset. * It could also be reproduced on an AMD based system with NVIDIA nForce 520 chipset. * It could also be reproduced if only {{{smartctl -i}}} is used. This command sends only one ATA command to the disk: IDENTIFY DEVICE. No SMART functionality is used then. * It could also be reproduced with {{{hdparm -I}}} on Linux. ---- 2010-11-26, updated 2010-11-30: The info is published on [http://www.heise.de/newsticker/meldung/SMART-Tool-beschaedigt-Daten-auf-Samsung-Festplatte-Update-1143120.html heise online news] (German). ---- 2010-11-30: We could reproduce the problem. Tested on an Intel based system with P35 chipset under Linux ([http://grml.org/ grml] 2010.04 Live CD). NCQ and disk write cache are enabled. {{{ # uname -a Linux grml.somewhere 2.6.33-grml #1 SMP PREEMPT Fri Apr 2 10:16:25 UTC 2010 i686 GNU/Linux # smartctl -i -q noserial /dev/sda smartctl 5.40 2010-10-16 r3189 [i686-pc-linux-gnu] (local build) Copyright (C) 2002-10 by Bruce Allen, http://smartmontools.sourceforge.net === START OF INFORMATION SECTION === Device Model: SAMSUNG HD204UI Firmware Version: 1AQ10001 User Capacity: 2,000,398,934,016 bytes ... # cat /sys/block/sda/device/queue_depth 31 # hdparm -W /dev/sda /dev/sda: write-caching = 1 (on) }}} First run one of these commands in another terminal window: {{{ # watch -n 1 smartctl -i /dev/sda }}} or: {{{ # watch -n 1 hdparm -I /dev/sda }}} With the above command running concurrently the problem can be reproduced as follows: {{{ # dd if=/dev/zero of=/dev/sda count=1000000 1000000+0 records in 1000000+0 records out 512000000 bytes (512 MB) copied, 12.7394 s, 40.2 MB/s # badblocks -vw -b 512 -t 0x55 /dev/sda 1000000 Checking for bad blocks in read-write mode From block 0 to 1000000 Testing with pattern 0x55: done Reading and comparing: 36608 ... 36671 107200 ... 107263 169984 ... 170047 245824 ... 245887 321216 ... 343615 606336 ... 606399 875520 ... 875583 done Pass completed, 256 bad blocks found. # od -A x -x -N 100000b /dev/sda 000000 5555 5555 5555 5555 5555 5555 5555 5555 * 1180000 0000 0000 0000 0000 0000 0000 0000 0000 * 1188000 5555 5555 5555 5555 5555 5555 5555 5555 * a7c0000 0000 0000 0000 0000 0000 0000 0000 0000 * a7c8000 5555 5555 5555 5555 5555 5555 5555 5555 * 12810000 0000 0000 0000 0000 0000 0000 0000 0000 * 12818000 5555 5555 5555 5555 5555 5555 5555 5555 * 1ab80000 0000 0000 0000 0000 0000 0000 0000 0000 * 1ab88000 5555 5555 5555 5555 5555 5555 5555 5555 * 1e848000 }}} The above suggests that the disk sometimes discards a pending 64 sector write command when a IDENTIFY DEVICE command is received. This data loss occurs silently. There is no error message in kernel log, SMART Error log, NCQ Command Error log page, or SATA Phy Event Counters log page. The problem could '''not''' be reproduced with the above test if any of the following conditions are met: * Disk write cache is disabled. * NCQ is disabled. This may not always be true as the c't lab also reported problems with NCQ disabled. * A modified test version of smartctl which does not issue IDENTIFY DEVICE commands is used. Then all other SMART and non-SMART commands used by smartctl work without any data loss. Christian Franke ---- If you have additional info, please report it to the [mailto:smartmontools-support@lists.sourceforge.net smartmontools-support mailing list].