install on dell server with cerc raid, need some tips

Hi

I want to install opensuse on a poweredge 830 server with a cerc 1.5/6 hardware raid configuration, since i have no previous experience with linux I’m having a hard time to grasp the way to do things. But i would love if someone can direct me to a good tutorial or document where i can learn more. At this moment I’m stuck (though i decided to install using default options yast gave me, just to test) with partitioning and RAID.

So this is what i would like to know:

Conditions:
*Server currently has a windows 2003 installed but I don’t need it so actually that is going to go away
*this is a small network, less than 30 users
*Server is going to be used to authentificate users through openldap, also is going to serve files (since we do printing many of them would be 100mb +), and also depending on performance may be used as printing server too (i know that’s a lot of tasks but besides printing other functions won’t be used that much)
*Server has 2 phisical HD that i want to use with RAID 5 or 6 there are drivers for that already in dell’s webpage

  • I’m installing openSUSE 11.4

Questions

1.- Does linux really needs a dedicated swap partition
2.- If so how raid works with that, is it going to be mirrored too (I don’t think)
3.- Is it better to install linux in 1 HD only with no swap partition, leave the other blank and install raid after linux is up
4.- What’s up with ext units, in the sense that now it looks like there are too many units… not only the simple ‘os, data’ i’m used to

Objective
1.- I just want to have a linux installation with raid 5 configuration using 2 hd

Again thanks a lot for the help, didn’t want to make a post so long but I prefer to give all the important info at once. I know these are very basic question they even may not be related to linux but computers in general. if someone can answer will be great but if at least i can get a hint to the right direction would be ok too

Heloz wrote:
> I want to install opensuse on a poweredge 830 server with a cerc 1.5/6
> hardware raid configuration, since i have no previous experience with

Caveat - I know nothing about Dell or cerc. Please check carefully just
what type of ‘hardware’ it really is.

This site may be helpful - http://raid.wiki.kernel.org/

> 1.- Does linux really needs a dedicated swap partition

Not strictly, but it’s a lot easier to just assume that it does. But you
can dynamically add swap just by using files.

> 2.- If so how raid works with that, is it going to be mirrored too (I
> don’t think)

I wouldn’t put it on RAID but it depends what you’re trying to achieve.

> 3.- Is it better to install linux in 1 HD only with no swap partition,
> leave the other blank and install raid after linux is up

That’s what I would do. Format both disks with smallish partitions at
the beginning and the end. Put the system in one of those partitions;
put swap in the other on the same disk. Install. Configure the large
partitions in RAID1 (see below) and then format as LVM. Then make
logical volumes/filesystems for whatever data you want. Make a spare
copy of the operating system and another swap partition in the small
partitions on the second disk.

> 4.- What’s up with ext units, in the sense that now it looks like there
> are too many units… not only the simple ‘os, data’ i’m used to

I don’t understand what you mean.

> Objective
> 1.- I just want to have a linux installation with raid 5 configuration
> using 2 hd

That doesn’t make sense. If you have two disks, use RAID 1. Read e.g.
wikipedia on types of RAID.

  1. no It does not need to be dedicated. But it is recommended.
  2. depends on the type of RAID ie is it real hardware RAID/FAKE(BIOS assist)/Software?? Real and FAKE both do the whole disk Real is totally transparent to the OS the hardware does all the work. FAKE requires the OS to do some of the work and may or may not work with Linux depending on what exact chip set. Software will only work for Linux no support at all in Windows but you can set it to work with only selected partitions…
  3. IMO only your real data needs to be on RAID. But others may differ. RAID is not a backup method. You still need backups. Important data should be on it’s on partition
  4. no idea what you ask

RAID 5 needs 4 hard drive to the best of my knowledge. Striped and mirrored

Thanks for the answers

a.-Actually dj you’re right it’s raid 1 since i want to mirror one of the devices, not as a backup but to be sure the ldap is always up to athentificate.

b.- I’m gonna follow you’re advice, I’ve been reading more about logic volumes so should be easy to decide the setup later (specially bcs the suse installation is taking forever… it’s been already 3 hours and 2nd section of installation step is just beginning, at this rate it’s gonna take like 6 hours to install and also takes like 2 minutes to respond to mouse inputs)

c.-I’m going to divide a drive in os/data/swap partitions and going to mirror the os/data partitions with the second drive (i’m still thinking in terms of physical drives maybe i should study more about logic volumes)

d.-Regarding point 4 about the ext partitions is ok, I’ve been reading more and more careful about unix file system and i think now i understand why yast showed me so many partitions options on the installation :slight_smile:

e.- Again thanks a lot for the help, by the way I found some good guides on the spanish forum

f.-gogalthorp according to dell server specs i think it’s hardware raid not software, i’d like to verify in the server bios but at his moment is locked up with this eternal suse installation

Update

there’s no raid option on server’s bios, but there’s a driver speacially made for raid chpset (it writes the firmware) so I supose you use an utility to setthat up.

I had to restart installation, but this time i turned off the second hd, andnow is behaving normally and installation seems to be ok,no longer slow

The funny thing is that yast still detects the second drive though i turned it off in the bios

the RAID BIOS is different from your system BIOS. To access it, you usually need to type some key combo (Ctrl-G on some intel servers), it is usually shown on boot when the RAID system starts.

Your manufacturer usually gives you a LiveCD that allows to graphically set up the RAID system.

As for the swap partition, if I recall (I’m not sure though), you can use a partition for RAID setup and another one for something else, meaning:

  1. format each drive with 2 partitions (or more) one taking all but (for example) 2GB at the end, that will be for the RAID, the last 2GB partition will be used for swap
  2. enter your RAID BIOS system and use the big partitions to build a RAID system
  3. boot your linux install disc and install (DELL’s PERC system is usually an MPT or LSI RAID system, usually well recognized…)

if this can’t be done this way, partition your drives the same way, and then build a RAID1/5/10 (raid5 needs at least 3 drives) with the big partitions,
and then build a RAID0 system with striping using the 2GB partitions.

when done, you should install DELL management tools on your system for monitoring RAID and general state. you should have a Dell OpenManage CD provided.

hope it helps.