Monthly Archives: October 2026

How to check Oracle Exadata Compute node temperature sensors

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On an Exadata compute/database server, check temperature through the server’s ILOM service processor. CellCLI is for storage cells; it is not the compute server’s sensor interface. Oracle: Exadata ambient temperature monitoring

Ambient intake temperature on one node:

ipmitool sunoem cli "show /SYS/T_AMB"

Look for the value in °C and the sensor’s alarm_status.

List temperature sensors:

ipmitool sdr list | grep -iE 'ipmitool sdr list | grep degrees'

Example:

ipmitool sdr list | grep degrees

T_IN_ZONE0 | 40 degrees C | ok
T_IN_ZONE1 | 43 degrees C | ok
T_IN_ZONE2 | 37 degrees C | ok
T_IN_ZONE3 | 43 degrees C | ok
T_OUT_ZONE0 | 41 degrees C | ok
T_OUT_ZONE1 | 44 degrees C | ok
T_OUT_ZONE2 | 43 degrees C | ok
T_OUT_ZONE3 | 47 degrees C | ok
PS0/T_IN | 44 degrees C | ok
PS0/T_OUT | 47 degrees C | ok
PS1/T_IN | 42 degrees C | ok
PS1/T_OUT | 48 degrees C | ok
T_AMB | 31 degrees C | ok

For sensor readings and thresholds, Oracle ILOM also documents ipmitool sensor; available sensors depend on the server model. Oracle ILOM: Display sensor list · Oracle ILOM: IPMItool commands

Check ILOM health and open hardware problems from the ILOM CLI:

show /System health
show /System/Open_Problems
show /SYS/T_AMB

Oracle’s Exadata guidance gives a rack ambient operating range of 5–32 °C, with 21–23 °C as the optimal range. Those are ambient conditions; use each sensor’s reported status and thresholds for component sensors.

Oracle Exadata CellCLI Quick Reference

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Run cellcli on the storage cell, or run a single command from the OS shell with cellcli -e "...". CellCLI commands apply to the local cell; -m starts CellCLI in read-only monitor mode. Oracle: Starting CellCLI · Oracle: CellCLI command syntax

Cell and service health

cellcli -e "list cell detail"
cellcli -e "list cell attributes name,status,cellsrvStatus,msStatus,rsStatus,fanStatus,powerStatus,temperatureStatus"

Check cell status, CELLSRV/MS/RS, and hardware status attributes. list cell detail shows the full set of cell attributes.

Disk health and mapping

cellcli -e "list physicaldisk"
cellcli -e "list physicaldisk where status != normal detail"
cellcli -e "list celldisk"
cellcli -e "list celldisk where status != normal detail"
cellcli -e "list griddisk"
cellcli -e "list griddisk where status != active detail"
cellcli -e "list griddisk attributes name,asmModeStatus,asmDeactivationOutcome"
cellcli -e "list diskmap"

Typical states to check are physical disk normal, cell disk normal, and grid disk active. For ASM, asmModeStatus=ONLINE means ASM is using the grid disk; asmDeactivationOutcome=Yes means it can be deactivated without data loss. Treat that last attribute as status information, not authorization to deactivate a disk. Oracle: Physical disks · Oracle: Grid disks

LIST DISKMAP helps map physical disk slots and serials to cell disks and grid disks. Oracle: LIST

Alerts and cache

cellcli -e "list alerthistory where ageInMinutes < 1440 detail"
cellcli -e "list flashcache detail"
cellcli -e "list flashlog detail"

Alert history includes past alert records; review timestamps, severity, and messages to understand whether an alert is current or historical. Oracle: Alert history

CellCLI syntax tips

LIST <object> [WHERE <filter>] [ATTRIBUTES <attr-list>] [DETAIL]
DESCRIBE <object>
HELP

Examples:

LIST CELLDISK WHERE status != normal ATTRIBUTES name,status,physicalDisk
DESCRIBE GRIDDISK

Commands and object names are generally case-insensitive, and the ending semicolon is optional. DETAIL prints attributes one per line; ATTRIBUTES selects specific fields. Oracle: LIST command

tmux Quick Reference

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DDefault prefix: press Ctrl-b, release it, then press the command key. Example: Ctrl-b, then c. tmux Getting Started

Sessions

tmux new -s work       # Start a named session
tmux ls                # List sessions
tmux attach -t work    # Reattach to a session
tmux kill-session -t work

Ctrl-b d detaches from a session; it keeps running in the background.

Default keys

KeysAction
Ctrl-b cCreate a window
Ctrl-b ,Rename current window
Ctrl-b n / pNext / previous window
Ctrl-b 0–9Select window by number
Ctrl-b wChoose a window
Ctrl-b %Split pane left/right
Ctrl-b "Split pane top/bottom
Ctrl-b + arrowMove to pane in that direction
Ctrl-b oCycle through panes
Ctrl-b zZoom or unzoom current pane
Ctrl-b xClose current pane
Ctrl-b &Close current window
Ctrl-b [Enter copy mode; press q to leave
Ctrl-b dDetach
Ctrl-b ?Show key bindings
Ctrl-b :Open tmux command prompt

Window and pane close commands ask for confirmation. Key bindings can be listed with Ctrl-b ?; the official guide explains the prefix sequence and command prompt. tmux Getting Started

Commands at the tmux prompt

Press Ctrl-b :, type a command, then press Enter.

new-window -n logs
split-window -h          # Left/right panes
split-window -v          # Top/bottom panes
select-window -t :2
select-pane -L           # Or -R, -U, -D
resize-pane -L 5         # Resize by 5 cells

Remember

  • Session: a workspace that can keep running after you detach.
  • Window: like a tab within a session.
  • Pane: a split terminal within a window.
  • Default prefix is Ctrl-b; tmux settings can change it. tmux(1) manual

How to copy a directory and everything inside it while preserving permissions and timestamps

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Use cp -a to copy a directory and everything inside it while preserving permissions and timestamps:

cp -a /path/to/source_dir /path/to/destination/

If the destination directory doesn’t exist, it will be created. To copy only the contents of the source directory into an existing destination:

cp -a /path/to/source_dir/. /path/to/destination/