[H-GEN] Linux file server

[Josh Marshall]

On Fri, 2 Jul 2004 10:34, Tim Browne wrote:
> Hi All,
> I want to build a cost effective Linux file server. My thoughts were to run
> an ATA raid system with Samba and use a writable DVD for backup.

Hi Tim,

If you're wanting to build a cost effective, *reliable* linux file server, 
here are my suggestions (note this isn't the only way, just what I see to be 
the best way for the $$)

IDE drives are definitely cheaper and if performance isn't a major concern 
then these are ok. The problem with IDE drives is that they are cheap and are 
likely to fail. This is where RAID comes in. The 8mb cache drives seem to be 
of a higher quality and usually carry a longer warranty period, so I'd 
suggest these.

I'd suggest that you keep as close as possible to available hardware. Standard 
motherboards / generic ide controllers / easily available hard disks etc. In 
the event of a failure it will be quick and cheap to find a replacement 
(compared to a raid card, exotic sized scsi disk etc)

I believe that data redundancy on a critical server is being responsible. The 
slightly different performance (often indistinguishable to the users) is 
worth the hours of pain of restoring a system from backups while all the uses 
roam around the office like lost sheep...

I've found that software raid in linux is quite stable, relatively easy to use 
and doesn't require you buy the exact same hard drive size (you can raid 
partitions, not just whole disks). If you use software raid1 then the 
performance doesn't suffer much, and if a drive fails the system keeps going. 
Yes it's not hot-swappable but you want a cost-effective solution and 
downtime is difficult to avoid unless you have a redundant pair of servers.

I've found that running software raid on the root disk is not difficult and 
very handy, especially if you don't fully trust the hardware (there is an 
argument that you get what you pay for, but there is a chance that even the 
most expensive parts fail. So I don't trust any hardware)

I would suggest to run the operating system on a different pair of disks to 
the data. This is not costly but the performance gain is noticeable and it's 
easier to upgrade later on.

The data should be on a RAID-1 with an LVM above that, so that you can extend 
the data partition size across extra disks when you run out of space, and you 
can use its snapshotting facility to make clean backups.

In my opinion, to add my 2c to the other discussions on this thread, that RAID 
is for reliability and backups are for archival purposes. If a hard drive 
dies, it is RAID that should save you. If a user deletes a file, its the 
backup system that saves you. Two different circumstances and two different 
technologies that can work together to make your life easier.

I would suggest also that you look at using a network backup system like 
backuppc to take regular backups to another machine, and use its archive 
facility periodically (weeky/fortnightly/monthly whatever) to make offsite 
backups.

As this is a linux system there are many ways you can set your server up, I 
hope you can use my opinions to help make your decision easier.

Regards,
Josh.