ZyXEL NSA-2401 User Guide - Page 157

Chapter 6 Storage Screens Table 42 S.M.A.R.T. Attributes (continued) ID ATTRIBUTE NAME BETTER DESCRIPTION 12 Device Power Cycle Count This is the number of times the hard drive has gone through a full power on and power off. 13 Soft Read Error Low Rate This is the number of uncorrected read errors the hard drive has reported. If this is not zero, back up your data. 190 Airflow Low This indicates the temperature of the airflow measured by a Temperature Western Digital hard drive. 190 Temperature Difference from 100 High This indicates the value of 100 - the temperature in degrees Celsius. Manufacturers can set a minimum threshold that corresponds to a maximum temperature. 191 G-sense error Low rate This is the number of mistakes caused by impact loads. 192 Power-off Low Retract Count This is how many times the heads are loaded off the media. 193 Load/Unload Low This is the number of load and unload cycles into head landing Cycle zone position. 194 Temperature Low This is the hard drive's internal temperature. 195 Hardware ECC High Recovered This is the time between ECC (Error Correction Code)-corrected errors. 196 Reallocation Low This is the total number of reallocation (remap) operations. The Event Count raw value is the total attempts to move data from reallocated sectors to a spare area. Successful and unsuccessful attempts are both included. 197 Current Pending Low Sector Count This is the number of unstable sectors awaiting reallocation. If the sector is later successfully written or read, this value decreases and reallocation is not performed. Only failed write attempts cause a reallocation, not read errors. This can be difficult to test since only direct I/O writes to the disk cause reallocations, not cached writes. 198 Uncorrectable Low Sector Count This is the number of errors reading or writing a sector that were not correctable. An increase in this value is an indicator of disk surface defects or mechanical subsystem problems. 199 UltraDMA CRC Low Error Count This is the number of data transfer errors through the interface cable according to the ICRC (Interface Cyclic Redundancy Check). 200 Write Error Rate / Low Multi-Zone Error Rate This is the total number of errors in writing sectors. 201 Soft Read Error Low Rate This is the number of read/write head off-track errors. If the value is not zero, make a backup. 202 Data Address Low Mark Errors This is the number of data address mark errors. This could also be a different, manufacturer-specific attribute. 203 Run Out Cancel Low This is the number of ECC (Error Correction Code) errors. 204 Soft ECC Correction Low This is the number of errors corrected by software ECC (Error Correction Code). 205 Thermal Asperity Low Rate (TAR) This is the number of thermal asperity errors. Thermal asperity is a read signal spike caused by sensor temperature rise due to touching the disk surface or contaminant particles. 206 Flying Height This is the height of the hard drive's read/write heads above the disk surface. NSA-2401 User's Guide 157