# [solved] Linux Raid Questions

## massctrl

Hi all,

I have installed 2 160 GB ide disks in my desktop.

I want to give the linux raid software a shot.

I'm plannen plain raid 1

2 questions:

When doing fdisk /dev/hdc I get :

```

The number of cylinders for this disk is set to 19457.

There is nothing wrong with that, but this is larger than 1024,

and could in certain setups cause problems with:

1) software that runs at boot time (e.g., old versions of LILO)

2) booting and partitioning software from other OSs

   (e.g., DOS FDISK, OS/2 FDISK)
```

Could this have a negative impact on the Raid1?

How do I determine a correct chunk-size value?

This is my /etc/raidtab file:

```

raiddev /dev/md0

        raid-level      1

        nr-raid-disks   2

        nr-spare-disks  0

        persistent-superblock 1

        chunk-size      32

        device          /dev/hdc1

        raid-disk       0

        device          /dev/hdd1

        raid-disk       1

```

Anyone with tips and advice?

ThanksLast edited by massctrl on Fri Jan 05, 2007 9:02 am; edited 1 time in total

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## NeddySeagoon

massctrl,

Your fdisk is OK - thats a history lesson its providing. If you want to read it all google for The Large Disk HOWTO.

The chunk size thats best for you depends on the file size on the raid and the buffer memory on the drives.

The defualt is mostly harmless. You will need to test with different settings to detimine the effect with your files.

It makes little difference to raid 1 since the data is writine to all the partitions in the raid set.

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