Daniele's questions

I have used cryptsetup to encrypt an external hard drive.

I have no problem at using the encrypted hard drive in this way:

/sbin/cryptsetup luksOpen /dev/sdc1 backup   
// typing password   
// mounting the partition   
// doing something   
// unmounting the partition  
/sbin/cryptsetup luksClose /dev/mapper/backup

But my next requirement was to be able to do it without the need of typing a password.

Then I created a binary file with the hash of my password via this command:

hashalot -n 32 ripemd160 > volume_key 

and then:

/sbin/cryptsetup luksOpen -d volume_key /dev/sdc1 backup

but I get this error:

Command failed: No key available with this passphrase.

Any ideas guys?

In Linux if you type cat *, you will get something like this:

line1 from file1
line2 from file1
line1 from file2
line1 from file3
line2 from file3
line3 from file3

What I would like is to display a separator among files. Something like this:
line1 from file1
line2 from file1
XXXXXXXXXXXX
line1 from file2
XXXXXXXXXXXX
line1 from file3
line2 from file3
line3 from file3

Is that easily possible with a one-liner easy to type by heart?

We are a small company and we backup all our data daily on an external HD.

We are 5 of us. Each of us has got an external hard drive that brings everyday from home. That HD gets written with the daily backup and the guy brings the HD back home.

This is done every working day on rotation (every day a different guy).

I don't think logistically this is a great way to go. It is easy to forget to bring the HD and one of the guys can be sick or on holiday.

Can you please suggest a better solution given that we can't use an online service, we want to bring the daily backup offsite and we don't have a lot of money to spend on this?

Thanks, Daniele

This is the scenario. I have a local server in the office that I want to back up programmatically (via a bash script) everyday to an external hard disk that I will bring home.

The data in the hard disk must be encrypted.

I can see three viable solutions for that and I am here to ask your opinions about which one will work best for my case.

solution 1: encrypt each and every file via the backup script before copying it on the hard disk

solution 2: encrypt the entire volume on the HD

solution 3: buy an external hard drive that offers hardware encryption

My goals are:
* the solution should be easy to implement
* I need to be able to copy the entire backup to HD without human intervention (only using a script)
* I need to be able to read the backup on the HD programmatically (there shouldn't be any human entering the password)
* decrypting the files should be fairly quick
* the backup written on HD must be as reliable as possible

Thanks in advance, Daniele

Today I have shutdown'ed a production machine by mistake because I thought I was on my local machine. I know, novice mistake :-(

As a solution for it not to happen again, I was thinking to remove the execution permission for the shutdown command as that machine should be always on.

Is that a good idea? Can you see any unwanted side effect by doing that?

Cheers, Dan

I have this external harddrive:
_ Buffalo Ministation TurboUSB HD-PS250U2 250 GB
_ just formatted using ext3
_ 250 GB
_ interface USB2
_ SATA 150 internal interface
_ no hardware encryption
_ full specs can be found here: http://www.dooyoo.co.uk/external-hard-drive/buffalo-ministation-turbousb-hd-ps250u2-250-gb/details/

I was doing some data transfer benchmarks using a file foo.tar.bz2 on different machines. I just attached the hard disk to a USB port and copied the file from the computer's hard disk to the external one (using the cp command).

On my development machine (Linux CentOS) the data transfer rate is 33MBps (which is good).

My problem is with our office server. There the data transfer rate is 1MBps! How can it be so low?!

Some details about the office server:
_ Dell PowerEdge T300
_ running CentOS 64-bit
_ running VirtualBox
_ the benchmark was done on the host system, not on a virtual machine _ at the moment I don't think the server is particoularly busy

The output of "/sbin/hdparm -tT /dev/sda1" on my development machine is:
Timing cached reads: 4220 MB in 2.00 seconds = 2108.41 MB/sec
Timing buffered disk reads: 332 MB in 3.02 seconds = 110.10 MB/sec

The output of "/sbin/hdparm -tT /dev/sda1" on the server machine is:
Timing cached reads: 25500 MB in 1.99 seconds = 12795.49 MB/sec
Timing buffered disk reads: 398 MB in 3.01 seconds = 132.04 MB/sec

What do you think can be the problem?

I think there is problably a piece of software missing, maybe a driver or a kernel module.
Or maybe a configuration problem?
Or maybe VirtualBox is causing the problem?
Or maybe the issue is the speed of the machine's internal bus?

Thanks for reading, Daniele

We are an online business.

We have a very powerful server with hard disk mirroring in our office that we are using for a variety of internal business-critical functions.

We want to keep that machine in our office but we want to make sure it is as secure as possible (within reason).

Obviously we are already backing it up everyday off-site.

My question is more about not-too-expensive physical measures to protect the machine against thieves and disasters such as fire.

What would you suggest?

We are an online business. Currently we are using DVD's for our backups. The problem is we are running out of space.

We are considering two alternatives here:

• external hard disk drives
• tape drives

We require a copy to be taken off-site every time a backup is performed.
Presently we are backup up tens of gigabytes.

On my database server there is a cronjob that backups all the databases in a way that makes it easy to restore them.

It is something like this:
0 5 * * * /usr/local/bin/backup.php

The problem is that the website (using that db server) is very slow during that process. Even, Pingdom sends me a 'website down' alert at the start of the process.

To solve the problem, I have tried this change:
0 5 * * * /bin/nice -n 19 /usr/local/bin/backup.php

but it doesn't seem to improve the situation.

How is that possible? Probably the problem is the backup script locks the database. But if I don't lock the tables, the backup may not be consistent.

How would you solve the problem under these requirements? 1. no purchase of any hardware 2. easy to implement and maintain 3. no proprietary solutions