Howto Format a new RAID 5 HDD
 

Hi,

I'm trying to mount a 70G x3 HDD - configured as RAID 5.

I'm currently running Red Hat Linux 7.3. From the /var/log/messages it tells me that my RAID 5 HDD sits on sdb. But when I tried to mount it I'll get this message :

[root@neptune root]# mount /dev/sdb /mnt/adaptec
mount: /dev/sdb is not a valid block device


I have to mount it and then format it before I could partition it right?

How do I do this?

Regards,
Kamal

I've only done raid 5 once, but shouldn't a raid drive be /dev/md0. What you posted looks like the second SCSI drive connected to your machine instead of a raid array. Now, I think you can define what you want the array called, and if that is true then you could have defined sdb in the /etc/raidtab.

Is there any errors when you do a raidstart?

Howto Format a new RAID 5 HDD
 

hi musicman_ace,

thanks for your reply. maybe not enough info from my part.

my machine's architecture:

80G x2 SATA HDD - configured as h/w RAID 0 . Silicon image.

We've installed Red Hat 7.3 on it.

After installing the OS, it's time for me to configure my 73 x3 HDD:

73 x3 - using aacraid_drv_1.1.4-2322.rpm as the driver.

The OS could detect it. This is from my /var/log/messages :

Apr 1 06:55:10 neptune kernel: scsi2 : aacraid
Apr 1 06:55:10 neptune kernel: blk: queue f7427818, I/O limit 4095Mb (mask 0xffffffff)
Apr 1 06:55:10 neptune kernel: Vendor: ADAPTEC Model: raider_5 Rev: V1.0
Apr 1 06:55:10 neptune kernel: Type: Direct-Access ANSI SCSI revision: 02
Apr 1 06:55:10 neptune kernel: blk: queue f7427a18, I/O limit 4095Mb (mask 0xffffffff)
Apr 1 06:55:10 neptune kernel: Attached scsi disk sdb at scsi2, channel 0, id 0, lun 0
Apr 1 06:55:10 neptune kernel: SCSI device sdb: 290230016 512-byte hdwr sectors (148598 MB)

this is how i though that i should mount it as /dev/sdb . but i can't ...

any suggestions on how do i mount it, format it n later partition it?

regards,
kamal

To make the filesystem (before mounting)
EXT3: mkefs -j /dev/sdb
Reiser: mkreiserfs /dev/sdb
XFS: mkxfs /dev/sdb

Once formatted,
mount -t reiserfs /dev/sdb /mnt/place

My question remains. Are the 3 73GB drives a software raid or are they hardware raid?

Howto Format a new RAID 5 HDD
 

it's a hardware raid musicman_ace

Then you should be able to apply whichever filsystem on the array before mounting it to its destination.

i got this when i run mkfs -t ext2 /dev/sdb :

[root@neptune root]# mkfs -t ext2 /dev/hdb
mke2fs 1.27 (8-Mar-2002)
/dev/hdb is entire device, not just one partition!
Proceed anyway? (y,n) y
mkfs.ext2: No such device or address while trying to determine filesystem size

Which filesystem were you trying to apply? You wrote down two different commands for the filesytem, and two different hard drive devices in your post.

mounting HDD
 

hi musicman_ace,

i'm trying to mount /dev/sdb ... but i can't ...

from my previous msg, i got this error when i tried to mount /dev/sdb :

mkfs.ext2: No such device or address while trying to determine filesystem size

did i read it wrongly from the /var/log/messages?

then , what does this mean?


Apr 1 06:55:10 neptune kernel: scsi2 : aacraid
Apr 1 06:55:10 neptune kernel: blk: queue f7427818, I/O limit 4095Mb (mask 0xffffffff)
Apr 1 06:55:10 neptune kernel: Vendor: ADAPTEC Model: raider_5 Rev: V1.0
Apr 1 06:55:10 neptune kernel: Type: Direct-Access ANSI SCSI revision: 02
Apr 1 06:55:10 neptune kernel: blk: queue f7427a18, I/O limit 4095Mb (mask 0xffffffff)
Apr 1 06:55:10 neptune kernel: Attached scsi disk sdb at scsi2, channel 0, id 0, lun 0
Apr 1 06:55:10 neptune kernel: SCSI device sdb: 290230016 512-byte hdwr sectors (148598 MB)

regards,
kamal

Apr 1 06:55:10 neptune kernel: scsi2 : aacraid
Apr 1 06:55:10 neptune kernel: blk: queue f7427818, I/O limit 4095Mb (mask 0xffffffff)
Apr 1 06:55:10 neptune kernel: Vendor: ADAPTEC Model: raider_5 Rev: V1.0
Apr 1 06:55:10 neptune kernel: Type: Direct-Access ANSI SCSI revision: 02
Apr 1 06:55:10 neptune kernel: blk: queue f7427a18, I/O limit 4095Mb (mask 0xffffffff)
Apr 1 06:55:10 neptune kernel: Attached scsi disk sdb at scsi2, channel 0, id 0, lun 0
Apr 1 06:55:10 neptune kernel: SCSI device sdb: 290230016 512-byte hdwr sectors (148598 MB)

I understand that you have a hardware raid setup, but I read that message as saying sdb (2nd drive on scsi bus) is 150GB. Now three 73GB drives in raid 5 would equal that amount. So the next question I guess is do you have all the necessary kernel options either configured into the kernel or loaded as modules?

hi musicman_ace ...

i'm not sure how to answer your question.

if i have all the necessary kernel options configured into the kernel what do i do? or what do i need to do if it is loaded as modules?

Check to see if the kernel has the SCSI adapter driver built in, or if it is using some type of generic support.

cd /usr/src/linux
make menuconfig

It is always a good idea (in my mind) to compile a kernel for your hardware rather than a distrobutions CD trying to do it for you. Verify that each device is supported and remove unwanted or un-used support that you don't need.

You can gather the necessary infomation about your system by typing
lsmod
lspci

Also, you can look at many files inside of /proc to get more info.

Is your RAID controller onboard or is it a PCI card?

my RAID controller is a PCI card

What kernel are you useing?
What type of raid...software hardware?
What exact raid card are you useing?
Is it supported for that kernel version you are useing?

You can not mount and you can not format raw devices like /dev/sdb. You have to make a partition before formatting. After you have made the partition, you have to reboot and then you can format /dev/sdb1. Rebooting is needed after you created the partition with fdisk, cfdisk, or sfdisk.

Silicon Image is not a hardware RAID controller. It is a software RAID controller. It uses the main processor to handle the RAID requests. RAID 0 does not improve OS performance. RAID 1 increases OS performance because it can read two files instead of one file at a time. Also RAID 1, is more reliable than RAID 0 for a server or for any system that is using it to store the OS. Use RAID 0 for video capturing, huge graphic files, sound, but never use for an OS drive.

For RAID 5 to be effective, you need atleast four hard drives. Using three hard drives for RAID 5 is not enough if one hard drive fails.

Saying "We've installed Red Hat 7.3" does not give you any credit. Sheesh, say "I installed blah, blah" to give yourself credit. Please do not mix third person in first person.