Software projects/OS/Slackware/Advanced usage/RAID

WIP WIP WIP HURRAID

• Need to properly rebuild one array while completing.

RAID

• http://en.wikipedia.org/wiki/RAID
• We will use the robust native Linux software RAID.
• It's a feature that can be used on the Pandora, although not as useful than on a PC or a server, so let's have fun with it
• I will cover here only a RAID 1 (mirror) on two SD cards, as it should be the more interesting for a server usage because under read load, you can reach about 27MB/s against 16MB/s on one card.
• A SD + USB drive can also work although untested. As a two SD + USB drive.

Partitioning

• So you have to partition your system SD card differently than the default SL4P setup.
• In this example, we will use the recommended minimal 8G card for the slot 1.
• You can use a different sized card for the right slot. The minimum size is 4G for this second card, and we will use 4G in this example.
• The RAID 1 partitions must have the same exact size.

Card 1

• Partition that way:

6G ext2 for the system
256M for the swap
1.5G unformated RAID

• We left 256M free. NEVER fill an entire drive with a RAID array. Drives, ie. all 8G, doesn't necessary offer the same exact capacity, so you can get in trouble if you add a drive 32MB short.

Card 2

256M for the swap
1.5G unformated RAID
2G unused. Do what you want with it.

Remove a drive from the array

• It's likely to be the one in the right SD slot.

Repair the array

• Depending the size of your RAID partition and he data on it, it can take a while.