Spin up HDD in PUIS mode and wipe drive for new placement

  • Recently I came across an older DVR unit, taking into consideration I’m not one to pass up an opportunity to harvest tech, so I took the liberties I had been granted.

    Just want the commands and take your chances? Skip down beyond my rambling.

    Not much useful inside most of these units, but there was a mechanical HDD.

    The drive is a WD5000AVVS, after a bit of googling around, I found Western Digital made these specifically for a DVR application. In other words, not really made to support a desktop environment. No reason to let that stop me from adding it for basic storage.

    The drive was utilizing PUIS or Power [Up In Standby] , something WD came up with themselves, from the wiki:

    Power-up in standby (PUIS) or power management 2 mode (PM2; Western Digital specific) is a SATA or Parallel ATA (aka PATA) hard disk configuration which prevents the drive from automatic spinup when power is applied. The spinup occurs later by an ATA command, only when the disk is needed, to conserve electric power[dubious – discuss] and to avoid a power consumption peak caused by a simultaneous spin-up of multiple disks.

    Useful tip: Since the drive will not power up on boot, I had to connect the drive to a raid controller to get it to spin up. I’m sure there are other means, such as issuing ATA commands.

    Set PUIS mode on Western Digital Hard Drive

    Enter the hdparm command , for help on commands just type in:

    hdparm - get/set hard disk parameters - version v9.43, by Mark Lord.
    Usage:  hdparm  [options] [device ...]
     -a   Get/set fs readahead
     -A   Get/set the drive look-ahead flag (0/1)
     -b   Get/set bus state (0 == off, 1 == on, 2 == tristate)
     -B   Set Advanced Power Management setting (1-255)
     -c   Get/set IDE 32-bit IO setting
     -C   Check drive power mode status
     -d   Get/set using_dma flag
     -D   Enable/disable drive defect management
     -E   Set cd/dvd drive speed
     -f   Flush buffer cache for device on exit
     -F   Flush drive write cache
     -g   Display drive geometry
     -h   Display terse usage information
     -H   Read temperature from drive (Hitachi only)
     -i   Display drive identification
     -I   Detailed/current information directly from drive
     -J   Get/set Western DIgital "Idle3" timeout for a WDC "Green" drive (DANGEROUS)
     -k   Get/set keep_settings_over_reset flag (0/1)
     -K   Set drive keep_features_over_reset flag (0/1)
     -L   Set drive doorlock (0/1) (removable harddisks only)
     -m   Get/set multiple sector count
     -M   Get/set acoustic management (0-254, 128: quiet, 254: fast)
     -n   Get/set ignore-write-errors flag (0/1)
     -N   Get/set max visible number of sectors (HPA) (VERY DANGEROUS)
     -p   Set PIO mode on IDE interface chipset (0,1,2,3,4,...)
     -P   Set drive prefetch count
     -q   Change next setting quietly
     -Q   Get/set DMA queue_depth (if supported)
     -r   Get/set device readonly flag (DANGEROUS to set)
     -R   Get/set device write-read-verify flag
     -s   Set power-up in standby flag (0/1) (DANGEROUS)
     -S   Set standby (spindown) timeout
     -t   Perform device read timings
     -T   Perform cache read timings
     -u   Get/set unmaskirq flag (0/1)
     -U   Obsolete
     -v   Use defaults; same as -acdgkmur for IDE drives
     -V   Display program version and exit immediately
     -w   Perform device reset (DANGEROUS)
     -W   Get/set drive write-caching flag (0/1)
     -x   Obsolete
     -X   Set IDE xfer mode (DANGEROUS)
     -y   Put drive in standby mode
     -Y   Put drive to sleep
     -z   Re-read partition table
     -Z   Disable Seagate auto-powersaving mode
     --dco-freeze      Freeze/lock current device configuration until next power cycle
     --dco-identify    Read/dump device configuration identify data
     --dco-restore     Reset device configuration back to factory defaults
     --direct          Use O_DIRECT to bypass page cache for timings
     --drq-hsm-error   Crash system with a "stuck DRQ" error (VERY DANGEROUS)
     --fallocate       Create a file without writing data to disk
     --fibmap          Show device extents (and fragmentation) for a file
     --fwdownload            Download firmware file to drive (EXTREMELY DANGEROUS)
     --fwdownload-mode3      Download firmware using min-size segments (EXTREMELY DANGEROUS)
     --fwdownload-mode3-max  Download firmware using max-size segments (EXTREMELY DANGEROUS)
     --fwdownload-mode7      Download firmware using a single segment (EXTREMELY DANGEROUS)
     --idle-immediate  Idle drive immediately
     --idle-unload     Idle immediately and unload heads
     --Istdin          Read identify data from stdin as ASCII hex
     --Istdout         Write identify data to stdout as ASCII hex
     --make-bad-sector Deliberately corrupt a sector directly on the media (VERY DANGEROUS)
     --offset          use with -t, to begin timings at given offset (in GiB) from start of drive
     --prefer-ata12    Use 12-byte (instead of 16-byte) SAT commands when possible
     --read-sector     Read and dump (in hex) a sector directly from the media
     --security-help   Display help for ATA security commands
     --trim-sector-ranges        Tell SSD firmware to discard unneeded data sectors: lba:count ..
     --trim-sector-ranges-stdin  Same as above, but reads lba:count pairs from stdin
     --verbose         Display extra diagnostics from some commands
     --write-sector    Repair/overwrite a (possibly bad) sector directly on the media (VERY DANGEROUS)

    As we can see, there is a command we can utilize to change the PUIS setting of the drive:

    hdparm -s

    Of course you must enter the device name you wish to change the settings on. So we can use:


    The lsblk command will list all block devices in the system

    Which in this case spits out the following:

    sda      8:0    0 465.8G  0 disk 
    └─sda1   8:1    0 465.8G  0 part 
    sdb      8:16   0 465.8G  0 disk 
    └─sdb1   8:17   0 465.8G  0 part /media/rick/WD500GB
    sdc      8:32   0 465.8G  0 disk 
    └─sdc2   8:34   0     1K  0 part

    This is now that the drive is finished, formatted and partitioned in the system. Sometimes you’ll need a bit more data to make the choice as to which drive you’ll be schnookering.

    So we can use lsblk flags as well.

    lsblk --output MODE,NAME,FSTYPE,LABEL,UUID

    Which spits out the following infos:

    MODE       NAME   FSTYPE          LABEL   UUID
    brw-rw---- sda    isw_raid_member         
    brw-rw---- └─sda1                         
    brw-rw---- sdb                            
    brw-rw---- └─sdb1 ext4            WD500GB 4e423629-51e8-41b3-a9be-9c9af4d31732
    brw-rw---- sdc    isw_raid_member         
    brw-rw---- └─sdc2 

    Well I know the two disks which say raid member are not it, and at this point there is only three block devices in the system, so I’ll use /dev/sdb

    If we look at the hdparm command to turn on or off PUIS, it states the two options which are 0/1 = Off or On

    So the command I’ll run on /dev/sdb to wake it up with hdparm is:

    hdparm -s 0 /dev/sdb

    Done with that jazz. The drive should spin up when powered on. Lest, we are not finished here. We should clean things up a bit.

    For simplicity I enjoy the shred command, plus it sounds serious, which it is.

    To find shred commands, we just run:

    shred --help

    Which pukes out this:

    Usage: shred [OPTION]... FILE...
    Overwrite the specified FILE(s) repeatedly, in order to make it harder
    for even very expensive hardware probing to recover the data.
    Mandatory arguments to long options are mandatory for short options too.
      -f, --force    change permissions to allow writing if necessary
      -n, --iterations=N  overwrite N times instead of the default (3)
          --random-source=FILE  get random bytes from FILE
      -s, --size=N   shred this many bytes (suffixes like K, M, G accepted)
      -u, --remove[=HOW]  truncate and remove file after overwriting; See below
      -v, --verbose  show progress
      -x, --exact    do not round file sizes up to the next full block;
                       this is the default for non-regular files
      -z, --zero     add a final overwrite with zeros to hide shredding
          --help     display this help and exit
          --version  output version information and exit

    Remember, this can be done on any drive, so everything and anything will be lost to the abyss forever. Pay attention to which drive letter / name you are using.

    The default pass is 25 times, yea, I’ve never needed a 25 pass random write scrub and I hope never to. So we can use the flag -n to limit how many passes shred does.

    I enjoy seeing output, so I’ll use the -v or, Verbose / noisy output flag as well.

    I also had no idea what permissions were set, so I used the -f or Force flag As stated, this changes permissions to allow for the write procedure if required.

    If your obsessive about keeping things straight, use the -z flag also, this will add one more pass after ‘shredding’ and write zero’s across the drive. Instead of having the drive look as if someone intentionally randomly repeatedly wrote ‘junk’ to it. Just make your bed.

    The command I used to wipe the drive was as follows:

    shred -n 5 -v -f -z /dev/sdb 

    Let the shredding begin, here is the initial output:

    shred: /dev/sdb: pass 1/6 (random)...
    shred: /dev/sdb: pass 1/6 (random)...330MiB/466GiB 0%
    shred: /dev/sdb: pass 1/6 (random)...687MiB/466GiB 0%
    shred: /dev/sdb: pass 1/6 (random)...1.0GiB/466GiB 0%
    shred: /dev/sdb: pass 1/6 (random)...1.3GiB/466GiB 0%
    shred: /dev/sdb: pass 1/6 (random)...1.7GiB/466GiB 0%
    shred: /dev/sdb: pass 1/6 (random)...2.1GiB/466GiB 0%
    shred: /dev/sdb: pass 1/6 (random)...2.4GiB/466GiB 0%
    shred: /dev/sdb: pass 1/6 (random)...2.8GiB/466GiB 0%
    shred: /dev/sdb: pass 1/6 (random)...3.1GiB/466GiB 0%

    And this goes on for quite some time. Notice we used the -n 5 flag, for five passes, yet we can see shred is currently on pass 1/6. Good, this means the last pass will be all zeros.

    Go do something else until your ready to format and partition the drive. Let it run!

  • For a more comprehensive or detailed guide, as to securely wiping a drive, visit nixCraft-how-do-i-permanently-erase-hard-disk

Tmux Commands

screen and tmux

A comparison of the features (or more-so just a table of notes for accessing some of those features) for GNU screen and BSD-licensed tmux.

The formatting here is simple enough to understand (I would hope). ^ means ctrl+, so ^x is ctrl+x. M- means meta (generally left-alt or escape)+, so M-x is left-alt+x

It should be noted that this is no where near a full feature-set of either group. This - being a cheat-sheet - is just to point out the most very basic features to get you on the road.

Trust the developers and manpage writers more than me. This document is originally from 2009 when tmux was still new - since then both of these programs have had many updates and features added (not all of which have been dutifully noted here).

Action tmux screen
start a new session tmux OR
tmux new OR
tmux new-session
re-attach a detached session tmux attach OR
tmux attach-session
re-attach an attached session (detaching it from elsewhere) tmux attach -d OR
tmux attach-session -d
screen -dr
re-attach an attached session (keeping it attached elsewhere) tmux attach OR
tmux attach-session
screen -x
detach from currently attached session ^b d OR
^b :detach
^a ^d OR
^a :detach
rename-window to newname ^b , <newname> OR
^b :rename-window <newn>
^a A <newname>
list windows ^b w ^a w
list windows in chooseable menu ^a "
go to window # ^b # ^a #
go to last-active window ^b l ^a ^a
go to next window ^b n ^a n
go to previous window ^b p ^a p
see keybindings ^b ? ^a ?
list sessions ^b s OR
tmux ls OR
tmux list-sessions
screen -ls
toggle visual bell ^a ^g
create another window ^b c ^a c
exit current shell/window ^d ^d
split window/pane horizontally ^b " ^a S
split window/pane vertically ^b % ^a |
switch to other pane ^b o ^a <tab>
kill the current pane ^b x OR (logout/^D)
collapse the current pane/split (but leave processes running) ^a X
cycle location of panes ^b ^o
swap current pane with previous ^b {
swap current pane with next ^b }
show time ^b t
show numeric values of panes ^b q
toggle zoom-state of current pane (maximize/return current pane) ^b z
break the current pane out of its window (to form new window) ^b !
re-arrange current panels within same window (different layouts) ^b [space]
Kill the current window (and all panes within) ^b killw [target-window]
  • Mount NFS from Truenas

    mkdir -p /media/rick/pool1 chown -R rick:rick /media/rick/pool1

    Add the automount to: /etc/fstab

    truenas.thecave:/mnt/pool1 /media/rick/pool1 nfs user,auto 0 0

    Retstart Nautilus to see the share in files:

    killall nautilus

    For other shares, just repeat the same process under directory ‘media’ with the name of the share substituted

    read more
  • Again running smartctl after all is said and done:

    smartctl --all /dev/sda

    ddrescue-smartctl-after-rescue.png ddrescue-smartctl-2.png

    Yet an old drive in itself, I run the wheels off of them, and monitor regularly as anyone should.

    read more