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I recently purchased a new hard drive, for the sole purpose of storing a database. I am running Ubuntu 10.0.4.

Since I had not done this sort of thing before, I decided to use the GUI (Disk Utility) to format and mount the disk (to avoid any snarfus caused by typos etc at the command line).

I correctly identified the new drive and proceeded as follows:

  1. Elected to format the drive
  2. Selected type: 'Ext4'
  3. Selected the 'Take ownership of filesystem' checkbox
  4. Unchecked the 'encrypt underlying device' checkbox
  5. Provided a name for the new volume (mydata)

Once the device had been formatted, I then mounted the device as follows:

sudo mount /dev/sdb /mydata

I created the directory /mydata/pgdbdata

and changed ownership as follows

sudo chown -R postgres:postgres /mydata/pgdbdata

I check:

username@localhost:~$ ls -l /mydata/
total 20
drwx------ 2 root     root     16384 2012-06-19 23:05 lost+found
drwxr-xr-x 2 postgres postgres  4096 2012-06-20 19:04 pgdbdata

However when I change to postgres user:

username@localhost:~$ sudo su - postgres
postgres@localhost:~$ ls -l /mydata/
ls: cannot open directory /mydata/: Permission denied

Because of this permissions issue, I can start the postgresql service and I can't create the postgresql db cluster. I am stuck.

What am I doing wrong?

share|improve this question
From your question I suppose that /media/market_data/ is owned by user and group root. pgdbdata folder has been only chowned to user and group postgres. But you are checking a wrong folder? – pl1nk Jun 20 '12 at 23:34
@pl1nk: Sorry. That was a typo. I have corrected the text in my question. – Homunculus Reticulli Jun 21 '12 at 8:06
You should change the permissions of /mydata/ – pl1nk Jun 21 '12 at 8:34
up vote 0 down vote accepted

You have only changed permission of pgdbdata but not of mydata you should be able to do a ls -l /mydata/pgdbdata but if your postgresql user wants to see the content of mydata it has to have read access to that too.

share|improve this answer
Thanks. I don't know why or how I missed that ... Nothing like a second pair of eyes ... :) – Homunculus Reticulli Jun 21 '12 at 11:40
You're welcome. Sometimes you're just blind. Happens to me all the time ;-) – André Stannek Jun 21 '12 at 16:47

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