Jeff Welling's questions

With Hashicorp's Vault, is it possbile to generate a secret without revealing that secret to the user who generated it?

Along the lines of:

vault generate secret/my/awesome/secret 32

Where it would generate a string of 32 random characters, will store that in Vault, and will not show the resulting value to the user who created it without them without them explicitly requesting it with a

vault kv get

operation?

After a quick reading the Vault docs I was sure this would be possible but now that I've gone looking for details about how to do it I'm finding so little info that I'm not sure it's possible [yet].

This is a followup question to Cannot mount /dev/sdc1 on Debian 5.0, special device /dev/sdc1 doesn't exist

Basically, I have 6 SATA hard drives in a machine and I'm trying to create a RAID6 array with them. When I try to run the mdadm command to create (with the verbose option) a raid array, I see messages like "mdadm: super1.x cannot open /dev/sdf1: No such device or address" which are resolved by doing partprobe /dev/sdf and then re-running the mdadm command.

The problem is that I have to run partprobe after each reboot, and from experience I don't think this is normal behaviour -- on no other linux machine do I have to partprobe the device before I can use it. Something must be going wrong, but how do I troubleshoot this to find out what? Could this be caused by a hardware problem?

Edit: Additional note - before I seemed to only have this problem with one drive, but now I'm having it with 3 drives.

I'm wondering if the results of this SMART selftest indicate a failing drive, this is the only drive that comes up with 'completed: read failure' in the results.

# smartctl -l selftest /dev/sde
smartctl version 5.38 [i686-pc-linux-gnu] Copyright (C) 2002-8 Bruce Allen
Home page is http://smartmontools.sourceforge.net/

=== START OF READ SMART DATA SECTION ===
SMART Self-test log structure revision number 1
Num  Test_Description    Status                  Remaining  LifeTime(hours)   LBA_of_first_error
# 1  Extended offline    Completed: read failure       90%      8981         976642822
# 2  Extended offline    Aborted by host               90%      8981         -
# 3  Extended offline    Completed: read failure       90%      8981         976642822
# 4  Extended offline    Interrupted (host reset)      90%      8977         -
# 5  Extended offline    Completed without error       00%       410         -

The drive doesn't yet show any signs of failure, aside from the output from that SMART selftest. This is the output from a different drive in the same system which is currently running a SMART selftest

# smartctl -l selftest /dev/sdc
smartctl version 5.38 [i686-pc-linux-gnu] Copyright (C) 2002-8 Bruce Allen
Home page is http://smartmontools.sourceforge.net/

=== START OF READ SMART DATA SECTION ===
SMART Self-test log structure revision number 1
Num  Test_Description    Status                  Remaining  LifeTime(hours)  LBA_of_first_error
# 1  Extended offline    Self-test routine in progress 30%     15859         -
# 2  Extended offline    Completed without error       00%      9431         -
# 3  Extended offline    Completed without error       00%      8368         -


SMART Attributes Data Structure revision number: 16
Vendor Specific SMART Attributes with Thresholds:
ID# ATTRIBUTE_NAME          FLAG     VALUE WORST THRESH TYPE      UPDATED  WHEN_FAILED RAW_VALUE
  1 Raw_Read_Error_Rate     0x002f   200   200   051    Pre-fail  Always       -       1
  3 Spin_Up_Time            0x0027   176   175   021    Pre-fail  Always       -       4183
  4 Start_Stop_Count        0x0032   100   100   000    Old_age   Always       -       48
  5 Reallocated_Sector_Ct   0x0033   200   200   140    Pre-fail  Always       -       0
  7 Seek_Error_Rate         0x002e   100   253   000    Old_age   Always       -       0
  9 Power_On_Hours          0x0032   088   088   000    Old_age   Always       -       8982
 10 Spin_Retry_Count        0x0032   100   253   000    Old_age   Always       -       0
 11 Calibration_Retry_Count 0x0032   100   253   000    Old_age   Always       -       0
 12 Power_Cycle_Count       0x0032   100   100   000    Old_age   Always       -       46
192 Power-Off_Retract_Count 0x0032   200   200   000    Old_age   Always       -       34
193 Load_Cycle_Count        0x0032   200   200   000    Old_age   Always       -       13
194 Temperature_Celsius     0x0022   111   101   000    Old_age   Always       -       36
196 Reallocated_Event_Count 0x0032   200   200   000    Old_age   Always       -       0
197 Current_Pending_Sector  0x0032   200   200   000    Old_age   Always       -       1
198 Offline_Uncorrectable   0x0030   200   200   000    Old_age   Offline      -       0
199 UDMA_CRC_Error_Count    0x0032   200   200   000    Old_age   Always       -       1
200 Multi_Zone_Error_Rate   0x0008   200   200   000    Old_age   Offline      -       2

I'm trying to fix an odd problem I'm having that I've never seen or heard of before. I have a disk, /dev/sdc and I'm trying to mount it, but cannot.

sudo mount /dev/sdc1 /mnt
mount: you must specify the filesystem type

Ok, I remember it was ext3, so,

sudo mount -t ext3 /dev/sdc1 /mnt
mount: special device /dev/sdc1 does not exist

This I've never seen before either so I check /dev

ls /dev | grep sdc
brw-rw----  1 root disk      8,  32 2011-04-20 03:27 sdc

There's supposed to be an sdc1 file there as well right?
fdisk shows

Disk /dev/sdc: 500.1 GB, 500107862016 bytes
255 heads, 63 sectors/track, 60801 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x1a2b2e31

   Device Boot      Start         End      Blocks   Id  System
/dev/sdc1               1       60801   488384001   83  Linux

So, from looking at fdisk it should be there, but it isn't. Checking /var/log/syslog, there are no messages from when I tried to mount the drive, so I don't know how to troubleshoot further. Does anyone know why this could be happening, or what I'm doing wrong, or how to fix this?

Could this be indicative of a dying device? There don't appear to be any SMART messages out of the ordinary in syslog..