Linux Blog

Hard drives are a vital part of system performance. They really are one of the biggest bottle necks in computing. Its nice to know how many MB/s your hard drives are capable of reading. If you perform the tests could share your results with other Linux Blog readers? With advances in hard drive technology I hope to see performance get better, and already see a major increase in performance over the old IDE type drives.

To check your hard drive read times use hdparm like so:

hdparm -t /dev/sdX

replacing sdX with whatever device your distribution assigned. Here are my results:

sda is my internal 80GB SATA drive.

/dev/sda:
Timing buffered disk reads: 224 MB in 3.02 seconds = 74.07 MB/sec

sdb is an internal 80GB IDE Drive

[owen@LinuxBlog ~]# hdparm -t /dev/sdb
/dev/sdb:
Timing buffered disk reads: 62 MB in 3.09 seconds = 20.06 MB/sec

sdc is an internal 160GB IDE drive

[owen@LinuxBlog ~]# hdparm -t /dev/sdc

/dev/sdc:
Timing buffered disk reads: 90 MB in 3.03 seconds = 29.70 MB/sec

The next two tests are rather interesting. sde is a brand new freshly formated 1TB external Western Digital MyBook Drive.

[owen@LinuxBlog ~]# hdparm -t /dev/sde

/dev/sde:
Timing buffered disk reads: 2 MB in 7.69 seconds = 266.25 kB/sec
[owen@LinuxBlog ~]# hdparm -t /dev/sde

/dev/sde:
Timing buffered disk reads: 68 MB in 3.01 seconds = 22.60 MB/sec

The first result was what the read time is like when you first initialize the drive. Since the drive was in power down, the read time was horrendous. This was fixed second time around. You will notice that the transfer rate over USB 2.0 is not all that bad in comparison to the internal IDE. Both IDE drives are not primary drives, and are also on the same channel. I’m not sure if that makes a difference or not. Also when I try to set DMA and 32 bit support I get an IOCTL error indicating that something went wrong, so I don’t think that this is a fair test.

Either way, post your results, if see if you can tweak the hard drive settings then see what the read times are. Check out my: Hard Drive Tuning with hdparm article.

Bookmark It

I got a new Linux desktop for use at my office.  All right, so its not entirely new but the price was right!

Here are the specs:

Motherboard: MSI K9N6SGM
CPU: AMD Sempron 3400+ 256 KB Cache, 1808.430 MHz and 3620.23 Bogomips (Slightly more than my laptop)
Ram: 1GB Generic Ram
Hard Drive: 80GB Sata Drive
Power Supply: 350 Watt

Now, considering I only paid around $200 for all of this I think I did pretty good. I already had an fairly new e-machine that was given to me with a fried motherboard, power supply and hard drive, so I used the Case DVD, Rom and CD-RW drive. Its a pretty fast machine so far. The onboard video happens to be a GeForce so I’m happy about my 3D Graphics support.

What is even better is that if you would like to support The Linux Blog and happen to need a new computer, you can call The Tech Fellows at (704) 780-4932 and tell them that The Linux Blog sent you and they will hook you up. Even if you just need parts they can help and normally can match Tiger Directs prices.

I will let you know how the rest of the installation of Slackware goes and post some benchmarks some time.

Bookmark It

Some times you run out of disk space. It just happens. So, what do you do when it does happen?

Well, it just happened to me and I’ll write about what I did. I’ll first start off with how I discovered that I was out of disk space in the first place. It was about 10:30 last night when for some reason that I can’t remember now I decided I’d start up my good old XP Virtual Machine (Probably to use some quirky Windows program.) Anyhow the VMWare console reported that I did not have enough disk space. This came as a bit of a shock to me as I have a 100GB hard drive. I had been downloading ISO’s of Linux Distributions but not that much. So, here is what to do when you run out of disk space:

Step 1) Don’t panic
Step 2) Take a look at your processes and shutdown anything that is not needed. init to single user mode if it makes you feel better.
Step 3) Use the disk free utility to figure out how much space you have:

df -h /

Step 4) Make a couple of megabytes of free space so that you can install a program.
Step 5) Download and install xdiskusage from source or from your favorite package manager.
Step 6) Run xdiskusage from the terminal as root
Step 7) Select a disk / partition
Step 8) Wait
Step 9) View the results
Step 10) Rinse wash repeat. (Browse Partitions / Delete / Move files to another disk & do it again)

Here are some screen shots of my xdiskusage:

Click For xdiskusage screenshots

As you can see from the root screen shot that my root partition that I have 60GB used between my /var and /home directories. On closer inspection, the var has 40GB, 20GB in virtual machines and 20GB in the logs directory. 20GB’s of logs is quite a lot, this is where my problem is. After finding the problem I was able to backup my log files and remove them. I know that this can be done with shell scripts xdiskusage has helped me in the past so I thought I’d pass on the information. If you have a favorite utility or script what you use when you run out of disk space let me know!

Project URL: http://xdiskusage.sourceforge.net/

Bookmark It

Changing your password under Linux is a pretty simple task providing you know how to do it, and of course since we’re talking about Linux: changing your password is as simple or complicated as you want it to be either way. You either love GUI’s or you hate them, so one method or the other can be confusing. I’m more of a console guy, but I’ll start with the GUI methods because thats probably what I think the masses want to see first. Remember what your doing tho, if you need to change the password on more than one box, I would look into changing your password by command line.

There is more than one reason to change your password, the examples below assume that you are just changing the current users password because it needs to be changed.

kdepasswd

passwd

If you need to change the password for another user, log in as root and execute the following:

passwd (username)

There are many ways to change your root password if you forgot it.

One way to do it is to boot up with a live CD, mount your hard drive, chroot and then execute the passwd command, once you reboot your password should be reset.

Bookmark It