Technical information

GALAXY® AUROURA LS CONFIGURATION AND SYSTEM INTEGRATION GUIDE
56 Section 3 Management
To return to the Main GUI screen, by clicking the Return to NumaRAID Main GUI Page link at
the bottom of the Config Details screen.
3.1.7 TRACE Details
The details of a ‘Trace’ command is very helpful to support the Aurora LS. In the example
above, “Commands” and “last 25” were chosen from the Config Details screen, then a
‘Display Trace’ was taken to capture that data. The trace shows the last 25 low-level
commands that were executed. Above the table is a description of what the trace has captured
– i.e. commands or all. It shows the total number of entries, how many it is displaying, and the
offset. In the table, on the left, we see the time in hours/minutes. These will almost never
change from one row to the next, unless the array is idle for a long period of time, has done
very few commands, or the commands are taking unusually long to execute. The entry column
shows the number for the particular entry in the Trace file. uGap is the number of
microseconds between commands. uSecs is the amount of time in Microseconds, that it took
to execute the command. User is the originator of the command. localhost indicates that the
array itself requested the command. Lun# is the logical LUN number of the LUN that the
command was performed on. Lun is the name of the LUN that the command was performed
on. CDB describes what command was issued, along with the length of the CDB (Command
Data Block). In the first line, for example, it says “READ10” – This means the command was a
read command, and the command data block for that command was 10 bytes long. To the
right of this a logical LBA. This is the logical block or sector that the command was told to act
on (in this case, read from). The next column is Length – this is the length of the data that the
command was told to act on – in this case, it was told to read 1024 bytes. Dirty is the number
of dirty segments in the cache. Status is the result of the command as reported by the device
– 0 indicates that the command was successful. A non-zero number indicates the command
failed.