Advice About Raid Cards And Large Hard Drives.

[pclinmike]

For my Backup server I was going to buy a PCI 4 port Raid card and 2 x 1TB (or larger)  SATA hard drives (get two more at a later date).
It's going to be used in an old pentIII with MiniMe OS (or RAW iso ?).

Anything to look out for before I getting the raid card or hard drives.

[Just17]

In some situations it is not possible to boot from the raid setup, and a separate boot disk might be required.

It is some time since I looked into this ....  I think the raid card must have a BIOS and the PC BIOS must have the required option to boot it ......................   ....... ......  or something to that effect .....  sorry cannot properly recall ....  but maybe will give you something to research before purchasing ........

[pclinmike]

Thanks .

Forgot to say these disc's are for storage only as there will be a small hard drive to boot from.

[Just17]

Thanks .

Forgot to say these disc's are for storage only as there will be a small hard drive to boot from.

In that case Linux compatibility will be the major concern when selecting the card, I guess.

[djohnston]

I hope you're not looking for blazing speed. Data bus speeds on a PIII motherboard are nothing to write home about. I spend a lot of time waiting for Synaptic to finally load, then refresh on mine. I'm talking minutes. An add-in hardware RAID controller needs to be compatible with the motherboard BIOS, as Just18 has said. The RAID controller will have a separate BIOS of its own, which will load and display on the screen immediately after the motherboard's. SCSI controllers are the same way. Make sure you get a controller that is both compatible with the PentiumIII's BIOS and with Linux. The first part will be the trickiest, I think.

Performance wise, you'd be better off buying a "bare bones" PC specifically for the job. It may even be the same cost or cheaper. You don't even need a hardware controller. You can do it just as well by using software RAID. But, most modern motherboards now have at least RAID1 support standard on the board. Personally, I think NAS is the way to go these days. Buy something with 4 storage bays, fill two of them to begin with, and add two more later. Connect to the network, and voila', you've got a dedicated file server.

[pclinmike]

I got some pent I,II and III for my testing machines.
With a bit of luck just had a Pent IV given me off freecycle so that will be a bit better, not bothered about speed as it's main job is to back up my daughters laptop over the internet while she is at uni.
There is a raid card on'Amazon' that will work on linux.
re ..  "I think NAS is the way to go these days" This will be a NAS when I have done, all its going to cost me is the Raid and two hard drives.

[djohnston]

Mike,

Would you care to document what you do? Would make a great magazine article. 

[pclinmike]

Mike,

Would you care to document what you do? Would make a great magazine article. 

PM sent.

[pclinmike]

Re, from above  "Forgot to say these disc's are for storage only as there will be a small hard drive to boot from."
Tried last night a using a SD card to boot off (with a SD to IDE interface ) looks promising.

[pclinmike]

An update.
I got a PCI raid card and two 2TB Sata hard drives and a SD card to IDE interface and 8GB SDhc card from Amazon uk..
The Bios detects the Raid card and the two drives, used the bios to set up Raid 1 array.

Bios also detects the SD card.

[root@localhost ~]# lspci
00:00.0 Host bridge: Intel Corporation 82845 845 [Brookdale] Chipset Host Bridge (rev 03)
00:01.0 PCI bridge: Intel Corporation 82845 845 [Brookdale] Chipset AGP Bridge (rev 03)
00:1e.0 PCI bridge: Intel Corporation 82801 PCI Bridge (rev 12)
00:1f.0 ISA bridge: Intel Corporation 82801BA ISA Bridge (LPC) (rev 12)
00:1f.1 IDE interface: Intel Corporation 82801BA IDE U100 Controller (rev 12)
00:1f.2 USB controller: Intel Corporation 82801BA/BAM USB Controller #1 (rev 12)
00:1f.5 Multimedia audio controller: Intel Corporation 82801BA/BAM AC'97 Audio Controller (rev 12)
01:00.0 VGA compatible controller: NVIDIA Corporation NV17 [GeForce4 MX 440] (rev a3)
02:08.0 Ethernet controller: Intel Corporation 82801BA/BAM/CA/CAM Ethernet Controller (rev 03)
02:09.0 RAID bus controller: Silicon Image, Inc. SiI 3114 [SATALink/SATARaid] Serial ATA Controller (rev 02)

Installed Minime 2012.02 on the SD card, updated also removed unwanted stuff.
Boots ok.

root@localhost ~]# df -T
Filesystem    Type    Size  Used Avail Use% Mounted on
/dev/sda1 reiserfs    4.9G  1.8G  3.2G  37% /
/dev/sda6 reiserfs    2.5G  181M  2.3G   8% /home

The two Storage only drives show up in 'Dolphin' as Two Drives

[root@localhost ~]# fdisk -l

Disk /dev/sda: 7948 MB, 7948206080 bytes
255 heads, 63 sectors/track, 966 cylinders, total 15523840 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x00085ba0

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1   *        2048    10233404     5115678+  83  Linux
/dev/sda2        10233405    15518789     2642692+   5  Extended
/dev/sda5        10233468    10426184       96358+  82  Linux swap / Solaris
/dev/sda6        10426248    15518789     2546271   83  Linux

Disk /dev/sdb: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x00045fe6

   Device Boot      Start         End      Blocks   Id  System
/dev/sdb1            2048  3907028991  1953513472    b  W95 FAT32

Disk /dev/sdc: 2000.4 GB, 2000398934016 bytes
255 heads, 63 sectors/track, 243201 cylinders, total 3907029168 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 4096 bytes
Disk identifier: 0x000348a1

   Device Boot      Start         End      Blocks   Id  System
/dev/sdc1            2048  3907028991  1953513472    b  W95 FAT32

I have been doing a lot of research and it looks like 'mdadm' is the best program to configure the two storage drives.
One of the links I found was  http://www.pclinuxos.com/forum/index.php/topic,89150.0.html
(thanks for link).
I want to use 'Raid 1 Array'.

Before I start to try to use 'mdadm' can anyone give me some guidance if you have used it.

[Just17]

too long ago for me to remember, sorry 

[djohnston]

I would recommend bookmarking this Linux RAID wiki. Go through all the info, step by step, that pertains to setting up and configuring what you have. Plan the partition layout before beginning. Spend as much time as it takes to test your setup before commiting any long-term data to it. Do you also plan to use LVM (Logical Volume Manager)? It gives you an easy way to resize storage volumes after the fact, without re-partitioning the drive(s).

What I'm curious about is your choice of filesystems. Reiser is okay, if you don't use it on large partitions. I used ReiserFS3 for years, and a manual or forced fsck can take a very long time to complete. I guess the 2TB disks came pre-formatted as FAT32? For archival, you definitely need a journaling filesystem, and FAT32 is not one. NTFS is, but, personally, I'd go with a Linux filesystem. XFS and ext4 are very fast, robust and reliable.

[pclinmike]

Thanks for the 'Wiki' link,

LVM .. Yes I would like to use it, But how ?.

re, "I guess the 2TB disks came pre-formatted as FAT32"  Yes that's correct, I have formatted them to XFS now ( If it's good enough for NASA it's good enough for
me ).

[pags]

Is your RAID card and actual, hardware RAID card?  If so, you should be able to go into the BIOS of the card (access during boot, usually after the the BIOS is finished initializing), and setup the RAID configuration there.  After that, they should appear as a single device to any OS, and you just create your file system, etc, etc.

If it isn't a "true hardware RAID" card (many consumer-grade RAID cards are essentially just multiple controllers, that use software to build the RAID configuration), then, yes, you will use mdadm to build the set.

[djohnston]

LVM .. Yes I would like to use it, But how ?.

I'm working on a howto doc for PCLinuxOS. Right now, other than the diskdrake GUI for partitioning, the LVM stuff is all command line. RHEL has an excellent GUI for LVM management named system-config-lvm that has been in use for years. I've been trying out some RPMs, but can't get around a slight python problem yet. I'd like to be able to request a system-config-lvm package for PCLinuxOS.

As far as what pags is talking about, have you gone into the RAID's BIOS at bootup time to configure the two drives as RAID1? You need to get that working first. Although LVM doesn't need RAID, it's why you bought the controller, to have redundant drives in case of a hardware failure.