Software projects/OS/Slackware/Advanced usage/RAID
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Revision as of 22:08, 17 April 2012 by Linux-SWAT (talk | contribs)
Contents
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.
- This array will be mounted as /srv , the standard server folder.
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
That's all for now, the third partition will be created under Slackware, and will be:
1.5G RAID
- We will 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
That's all for now, the other partitions will be created under Slackware, and will be:
1.5G unformated RAID 2G unused. Do what you want with it.
Install SL4P
- Uncompress the rootfs on the first SD card, first partition, put the card in your OP, and boot it.
- Log in.
Backup /srv
- As root:
mkdir /srv-save mv /srv/* /srv-save/
Finalizing card 1 setup
- As root:
cfdisk
Finalizing card 2 setup
- As root:
cfdisk
Create the RAID 1 array
Make the RAID permanent
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.