Difference between revisions of "RAID"

From Noah.org
Jump to navigationJump to search
Line 15: Line 15:
 
== Format ==
 
== Format ==
  
I created a 4GB partition on both drives for the operating system (boot and / on an ext3 partition). I left the rest of the drives unallocated. In other words, I installed the full operating system first on the 4GB partition before I even started with RAID configuration.
+
I created a 4GB partition on both drives for the operating system (boot and / on an ext3 partition). The first partition (4G) of each drive was formatted as ext3. I created a second partition on each drives. I left the this partition unformatted. In other words, I installed the full operating system first on the 4GB partition before I even started with RAID configuration. I didn't create a swap partition. I could have, but this machine has 1GB of RAM and will do no work besides SaMBa, so swap isn't going to help much.
  
This is not "ideal", but it's easier to setup. I'm building a NAS, so I don't care as much for the integrity of the operating system. I just care about the files in the file server. If the boot sector goes bad I can reinstall Linux and recover my files offline. A more clever system would allow the boot and operating system partitions to be on the RAID array itself.
+
After all is said and done I had two drives partitioned and formatted identically:
 +
 
 +
<pre>
 +
# fdisk -l
 +
 
 +
Disk /dev/hda: 180.0 GB, 180045766656 bytes
 +
255 heads, 63 sectors/track, 21889 cylinders
 +
Units = cylinders of 16065 * 512 = 8225280 bytes
 +
 
 +
  Device Boot      Start        End      Blocks  Id  System
 +
/dev/hda1  *          1        486    3903763+  83  Linux
 +
/dev/hda2            487      21889  171919597+  83  Linux
 +
 
 +
Disk /dev/hdd: 180.0 GB, 180045766656 bytes
 +
255 heads, 63 sectors/track, 21889 cylinders
 +
Units = cylinders of 16065 * 512 = 8225280 bytes
 +
 
 +
  Device Boot      Start        End      Blocks  Id  System
 +
/dev/hdd1              1        486    3903763+  83  Linux
 +
/dev/hdd2            487      21889  171919597+  83  Linux
 +
</pre>
 +
 
 +
This setup is not "ideal", but it's easier to setup. I'm building a NAS, so I don't care as much for the integrity of the operating system. I just care about the files in the file server. If the boot sector goes bad I can reinstall Linux and recover my files offline. A more clever system would allow the boot and operating system partitions to be on the RAID array itself.

Revision as of 16:40, 20 September 2007

My RAID setup for an Ubuntu NAS box.

Hardware

I used two identical PATA 180GB drives. Each drive was connected to a separate IDE bus (each has their own cable). Do not put two IDE RAID drives on the same IDE bus. Two drives on the same cable would slow everything down plus if one drive goes bad it brings down the entire IDE bus.

software

apt-get install mdadm
apt-get install dmraid

Format

I created a 4GB partition on both drives for the operating system (boot and / on an ext3 partition). The first partition (4G) of each drive was formatted as ext3. I created a second partition on each drives. I left the this partition unformatted. In other words, I installed the full operating system first on the 4GB partition before I even started with RAID configuration. I didn't create a swap partition. I could have, but this machine has 1GB of RAM and will do no work besides SaMBa, so swap isn't going to help much.

After all is said and done I had two drives partitioned and formatted identically:

# fdisk -l

Disk /dev/hda: 180.0 GB, 180045766656 bytes
255 heads, 63 sectors/track, 21889 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/hda1   *           1         486     3903763+  83  Linux
/dev/hda2             487       21889   171919597+  83  Linux

Disk /dev/hdd: 180.0 GB, 180045766656 bytes
255 heads, 63 sectors/track, 21889 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes

   Device Boot      Start         End      Blocks   Id  System
/dev/hdd1               1         486     3903763+  83  Linux
/dev/hdd2             487       21889   171919597+  83  Linux

This setup is not "ideal", but it's easier to setup. I'm building a NAS, so I don't care as much for the integrity of the operating system. I just care about the files in the file server. If the boot sector goes bad I can reinstall Linux and recover my files offline. A more clever system would allow the boot and operating system partitions to be on the RAID array itself.