The time has finally come. Linux guys, please come help me set up my RAID5 fileserver

[SiM]

Is there currently stable, reliable open source iSCSI target software for Linux?
Is this reliable?
http://iscsitarget.sourceforge.net/
If you install an iSCSI initiator on your PC's and you use gigabit ethernet you would potentially have ultra fast access to this box and the PC's would believe the LUN you set aside on the iSCSI target software is directly attached.

Rocketdivision do a free one for personal use
http://www.rocketdivision.com/download_starport.html

You have lost me completely.... My drives are SATA...

[directhex]

i think iscsi's overcomplicating matters a bit

[SiM]

OK RAID is set up. Is there a image host that is not blocked for you peterb?

Can you see this:

Directhex, does it look ok?

What are the advantages for having root, var and home on separate partitions? I don't think I can partition the 2tb array any more...

[peterb]

Thought the swap was a bit small.... Can't I put the root, var, home onto the array?
So
drive 1: 1GB /boot
drive 2: 1GB swap
drive 3: 1GB swap

The rest of the space goes to the array which will have partitions for root, home, var? Which will be configured automatically I guess? Or can these all be on same partition? Or is this not a good idea?

Yes - you don't have to have separate partitions for /var or /home - just makes it a bit easier (imho) to administer. You might wnat to consider LVMs which can sit on top of the RAID - but adds another layer of complexity.

Is there currently stable, reliable open source iSCSI target software for Linux?
Is this reliable?
http://iscsitarget.sourceforge.net/
If you install an iSCSI initiator on your PC's and you use gigabit ethernet you would potentially have ultra fast access to this box and the PC's would believe the LUN you set aside on the iSCSI target software is directly attached.

Rocketdivision do a free one for personal use
http://www.rocketdivision.com/download_starport.html

Yes there is - but I haven't got a reference for it to hand - but unless I have misunderstood what you are saying, I can't see much advantage in what you suggest. However Iscsi is quite useful for having a distibuted RAID across two machine - so if they are RAID 1 then you have replicated the data - potentially off site! While I never advocate RAID as a backup solution, this is perhaps one area when it 'might' be considered as that.

(On the backup side, if (Sim) you did implement LVM - taking a snaphot of a logical volume does give a good backup method. This is particularly relevant if you are running a database. I do that for my backups - take a snapshot of /var (which includes the Mysql database) which can then transferred to the back-up medium for long term storage. (I use tape)

[badass]

i think iscsi's overcomplicating matters a bit

For SiMs use, yes. I was adding this to the discussion partly for my own interest

SiM, iSCSI is a way of encapsulating SCSI packets within IP. Since the OS can also do that, a file server can pretend to be a single disk connected to the network, even though its actually a logical drive on a RAID array.
An iSCSI target makes the computer pretend to be an iSCSI disk, an iSCSI initiator installs drivers on your OS so you see that iSCSI disk as one directly attached to your computer. It avoids the CPU/network overhead in dealing with things like SMB for the file sharing etc on both machines.

[directhex]

OK RAID is set up. Is there a image host that is not blocked for you peterb?

Can you see this:

Directhex, does it look ok?

What are the advantages for having root, var and home on separate partitions? I don't think I can partition the 2tb array any more...

looks perfect to me, for your purposes

[SiM]

Great.... Although I am thinking of making some separate partitions now after reading this:
http://guides.radified.com/magoo/gui...planation.html

drive 1:
200mb /boot
1800mb / (root)
drive 2:
1000mb swap
250mb /tmp
750mb /usr
drive 3:
2000mb /var

Does this look ok? A bit smaller than you suggested before, but I would like to maximise the array size (but of course, I don't want it to get full and cause errors too)

[peterb]

No - most of the pic hosting sites are blocked! (So are the some of the adservers Hexus use - makes downloading pages a LOT faster - but thats reallyOT!)

That link pretty much sums up why I went for separate partitions for /var and /home. Just adds to flexibility.

BTW the root is just / /root is a directory for user root (the superuser). the concept of the filesystem layout is quite an important one to grasp (apologies if I am teaching you to suck eggs...)

Think of a tree - root is at the bottom, and as ypou branch out, you get the other sub directories - /usr /etc /var and so on. Thos can be mount points for other file systems on other disks - as you browse the filesystem, the OS pulls the files from wherever they are stored - the key point being that you browse the file system. This is different from Windows where you tend to browse the disk, so you can have two directories with the same name on different disks in Windows. With Linux you have a file structure where at a given level, each directory (or file - a directory is just a file with specific attributes) has aunique name, and could be on any disk or partition.

Generally in Linux "Everything is a file" - even a drive. As a user this doesn't matter - as admin it does. If you look at the file system you will see a directory /dev. That is the mountpoint for devices, and ypou can access the drive as (for example) /dev/hda1 Normally you wouldn't do that except for some admin tasks.

It is confusing and can be a tricky concept to grasp at first - but it is key to understanding the structure.

[SiM]

Ahh, I think I understand how it works now... Thanks peterb/directhex... I will google around for optimal sizing for each partition. I think it will be better in the long run to have separate partitions.

[peterb]

This link probably explains it better than I did!

http://www.freeos.com/articles/3102/

[SiM]

OK, so I have learned from my research that file servers don't need huge /var so this is what I have in mind:

Drive 1:
128mb boot
384mb tmp
2084mb var
1536mb swap

Drive 2:
4096mb usr

Drive 3:
4096mb \

Does this look good? I will put home onto the raid array.

This is a good read too for anyone else interested..

[directhex]

IMHO the "one large /" approach is reasonable if you don't know fully what you're going to store where

[SiM]

IMHO the "one large /" approach is reasonable if you don't know fully what you're going to store where

But then I won't be able to reinstall Ubuntu without killing the array... right?

How large does it need to be? Will the 4gb partition do? with home on the array...

Sorry for all the n00b questions...

[peterb]

It depends... !!!

You are going to use this as a file server - so is each user going to have a pribvate file store (I know we haven't considered this yet) or is it going to be one big shared file store?)

However you partition it, you need a separate /boot partition and a swap file partition.

For the / you need about 15 to 20 Gb. Reduce that by 5 if you use a separate partition for /var var contains the log files so it does tend to grow - but =you can quite happily leave /var on the same partition as /

You should really have a separat partition for /home which is where user directories will be located. If your are building an anonymous file store where all users can read write anything, you could create a /share directory (on its own partitio, or to keep things logically organised, just create /home/share - which will be a shared store.

As I say for my ssytem I have separate partitions for /boot / /var and /home but I only have a separate one for /var because that is where my webpages live and it makes backing up easier.

For the file store, my users have access to a shared drirectory /home/share and they all have shell accounts to give them private filestores. There are other ways of doing that, but as there are only 4 users, that was the quickest and easiest way to do it.

It is possible to change the drive/partition to file store allocation later (it means editing a file called fstab - usually found in /etc - fstab - why fstab?...File System Table) but it is less faff to get it as you want it first time round.

[SiM]

It will be all one shared store... so I won't need to mess with user permissions...

I have read in various different places that /var is not good to have on same partition as / as if something goes wrong the /var can grow out of control. Since there will be no websites or emails served off this, it doesn't need to be big afaik.

I thought I was overcomplicating it... so how does this sound then:

drive 1:
128mb /boot
384mb /tmp - may as well stick this here as the swap is already big enough
1536mb swap

drive 2:
2048mb /var

drive 3:
2048mb swap

then on the array I will put /

[SiM]

OK I am going to go with the above scheme... Thats /var and /tmp separate, but bill leave everything else in big / on array
Should the raid partitions be logical or primary?
And what file system should the array be? I remember one of you guys mentioning XFS...