On Thu, Mar 13, 2014 at 09:39:02PM -0600, Chris Murphy wrote:
>
> On Mar 13, 2014, at 8:11 PM, Marc MERLIN <[email protected]> wrote:
>
> > On Sun, Mar 09, 2014 at 11:33:50AM +0000, Hugo Mills wrote:
> >> discard is, except on the very latest hardware, a synchronous command
> >> (it's a limitation of the SATA standard), and therefore results in
> >> very very poor performance.
> >
> > Interesting. How do I know if a given SSD will hang on discard?
> > Is a Samsung EVO 840 1TB SSD latest hardware enough, or not? :)
>
> smartctl -a or -x will tell you what SATA revision is in place. The queued
> trim support is in SATA Rev 3.1. I'm not certain if this requires only the
> drive to support that revision level, or both controller and drive.
I'm not sure I'm seeing this, which field is that?
=== START OF INFORMATION SECTION ===
Device Model: Samsung SSD 840 EVO 1TB
Serial Number: S1D9NEAD934600N
LU WWN Device Id: 5 002538 85009a8ff
Firmware Version: EXT0BB0Q
User Capacity: 1,000,204,886,016 bytes [1.00 TB]
Sector Size: 512 bytes logical/physical
Device is: Not in smartctl database [for details use: -P showall]
ATA Version is: 8
ATA Standard is: ATA-8-ACS revision 4c
Local Time is: Thu Mar 13 22:15:14 2014 PDT
SMART support is: Available - device has SMART capability.
SMART support is: Enabled
=== START OF READ SMART DATA SECTION ===
SMART overall-health self-assessment test result: PASSED
General SMART Values:
Offline data collection status: (0x00) Offline data collection activity
was never started.
Auto Offline Data Collection: Disabled.
Self-test execution status: ( 0) The previous self-test routine completed
without error or no self-test has ever
been run.
Total time to complete Offline
data collection: (15000) seconds.
Offline data collection
capabilities: (0x53) SMART execute Offline immediate.
Auto Offline data collection on/off
support.
Suspend Offline collection upon new
command.
No Offline surface scan supported.
Self-test supported.
No Conveyance Self-test supported.
Selective Self-test supported.
SMART capabilities: (0x0003) Saves SMART data before entering
power-saving mode.
Supports SMART auto save timer.
Error logging capability: (0x01) Error logging supported.
General Purpose Logging supported.
Short self-test routine
recommended polling time: ( 2) minutes.
Extended self-test routine
recommended polling time: ( 250) minutes.
SCT capabilities: (0x003d) SCT Status supported.
SCT Error Recovery Control supported.
SCT Feature Control supported.
SCT Data Table supported.
SMART Attributes Data Structure revision number: 1
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME FLAGS VALUE WORST THRESH FAIL RAW_VALUE
5 Reallocated_Sector_Ct PO--CK 100 100 010 - 0
9 Power_On_Hours -O--CK 099 099 000 - 2219
12 Power_Cycle_Count -O--CK 099 099 000 - 659
177 Wear_Leveling_Count PO--C- 099 099 000 - 3
179 Used_Rsvd_Blk_Cnt_Tot PO--C- 100 100 010 - 0
181 Program_Fail_Cnt_Total -O--CK 100 100 010 - 0
182 Erase_Fail_Count_Total -O--CK 100 100 010 - 0
183 Runtime_Bad_Block PO--C- 100 100 010 - 0
187 Reported_Uncorrect -O--CK 100 100 000 - 0
190 Airflow_Temperature_Cel -O--CK 054 041 000 - 46
195 Hardware_ECC_Recovered -O-RC- 200 200 000 - 0
199 UDMA_CRC_Error_Count -OSRCK 100 100 000 - 0
235 Unknown_Attribute -O--C- 099 099 000 - 35
241 Total_LBAs_Written -O--CK 099 099 000 - 12186944165
||||||_ K auto-keep
|||||__ C event count
||||___ R error rate
|||____ S speed/performance
||_____ O updated online
|______ P prefailure warning
--
"A mouse is a device used to point at the xterm you want to type in" - A.S.R.
Microsoft is to operating systems ....
.... what McDonalds is to gourmet cooking
Home page: http://marc.merlins.org/
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