Disk monitoring

[Marcus Bauer]

On Mon, 2005-02-28 at 08:55 -0800, Matt Zimmerman wrote:

> The best answer to this is to use SMART to monitor the disks.  There is
> software for this in universe, but it would need some work to have it
> integrated properly "out of the box".
> 
> This was on the list of proposed goals for Hoary, but no one expressed
> interest in working on it.  If anyone reading this would like to work on
> such a project for the next release, contact me.

I'm using the smarttools on several machines but still believe that for
the average user a good backup and his five senses are the best weapon
against disk failure (i.e. when you realise that the makes strange
noises and programs start slower than usual...)

A sample output from a machine here:

Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE
  1 Raw_Read_Error_Rate     0x000b   100   100   032    Pre-fail  Always       -       60197
  2 Throughput_Performance  0x0005   100   100   020    Pre-fail  Offline      -       57
  3 Spin_Up_Time            0x0007   100   100   025    Pre-fail  Always       -       0
  4 Start_Stop_Count        0x0012   001   001   016    Old_age   Always   FAILING_NOW 65535
  5 Reallocated_Sector_Ct   0x0033   100   100   024    Pre-fail  Always       -       0
  7 Seek_Error_Rate         0x000b   100   100   020    Pre-fail  Always       -       280
  8 Seek_Time_Performance   0x0005   100   100   019    Pre-fail  Offline      -       1074003971
  9 Power_On_Hours          0x0012   027   027   020    Old_age   Always       -       39866799
 10 Spin_Retry_Count        0x0013   100   100   020    Pre-fail  Always       -       0
 12 Power_Cycle_Count       0x0012   098   098   020    Old_age   Always       -       342
196 Reallocated_Event_Count 0x0033   100   100   024    Pre-fail  Always       -       0
198 Offline_Uncorrectable   0x0010   100   100   020    Old_age   Offline      -       0
199 UDMA_CRC_Error_Count    0x000a   200   200   000    Old_age   Always       -       0
200 Multi_Zone_Error_Rate   0x000b   100   100   020    Pre-fail  Always       -       1792
203 Run_Out_Cancel          0x0002   094   094   020    Old_age   Always       -       408021827589


As you note Start_Stop_Count is "FAILING_NOW" but the disk is running
like a charme since over a year. As long as Spin_Up_Time and
Seek_Time_Performance are 100% I don't care at all as the spindle is
still in perfect condition.

A second thing to note here is that the Power_On_Hours are 39866799
which is about 5000 years, i.e. the manufacturer is storing seconds in
that value but smartctl doesn't know about this disk.

With the smarttools I experienced that the exception is quite often the
norm. 

I believe that the smartctl output is interesting on an engineering
level but it is very difficult to automagically produce reliable advice
from this to the enduser. 

AFAIK neither Redmont nor Apple are giving end user advice based on
S.M.A.R.T. info - Redmont may just be ignorant, but Apple?

IMHO this is only interesting on a server where you additionally monitor
the values over time and see the tendencies of the values.

Just my two pence.
Marcus