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QuimaxW

Member

From: Papua New Guinea

Registered: 2006-12-03

Posts: 228

Website

RAID or not to RAID

That is the question...

Long story: Personal server at home. It's on nearly 24x7, so I'm considering enterprise class hard drives wether I RAID or not. It's a MythTV backend, file storage, print server, web server, ect. I boot off of a single drive (that I really should back up here...) and I have 4 500GB drives in a Linux software RAID 5 as the shared storage.

The drives are aging and are failing. 2 failed earlier this year at the same time. Ug. They were in warranty and I received replacements, but had to do some special tricks to get all the files recognized again. I'm still finding corrupted files (pictures, videos, ect) on the array now that i have to replace from my out-of-date backup drive. So, I'm looking to replace my storage array.

I think my options are (and feel free to add others I haven't thought of!)
1) Another RAID 5 on 3 or 4 new drives.
2) 2 x 2TB drives in RAID 1
3) single drive
4) LVM setup? (Never done this at all...still not sure of the point of it...)

Is the complexity of RAID worth it in a world in of (relatively) inexpensive large hard disks?

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ewaller

Administrator

From: Pasadena, CA

Registered: 2009-07-13

Posts: 19,823

Re: RAID or not to RAID

Two comments related to the question:  What do you want from your RAID?

1. Always remember, having a redundant RAID does not mitigate the need for backups.  They [Raids] are nice because they avoid downtime in the event of a failure, but backups are still mandatory.  Do your requirements call for no down time in the event of a drive failure? Are your drive bandwidths such that replacement drives can rebuild within a reasonable period of time?

2.  Do you need the I/O bandwidth provided by the increased aggregate transfer speeds?  Is your raid controller capable of supporting the theoretical increase in bandwidth?  Is your server capable of supporting the higher bandwidths?

edit: clarified what I meant by "They"

Last edited by ewaller (2011-08-26 05:48:55)

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fukawi2

Ex-Administratorino

From: .vic.au

Registered: 2007-09-28

Posts: 6,224

Website

Re: RAID or not to RAID

You will need backups with or without the RAID, so the question is more like: does the expense of the extra drive(s) for RAID warrant the additional availability if the event of failure?

ie, With a non-RAID setup, can you deal with having the server down for 3 days while you source a replacement drive and restore backups?
Or do you want to spend the extra and setup RAID so the system can be running for those 3 days?

EDIT: Personally, I want the availability, so I run RAID-1 on my desktop as well as my server.

Last edited by fukawi2 (2011-08-26 05:28:44)

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ghen

Member

From: Belgium

Registered: 2010-08-31

Posts: 121

Re: RAID or not to RAID

The drives are aging and are failing. 2 failed earlier this year at the same time.

For RAID, always buy disks of different brand or type, or at least from different batches of the same brand/type.
This makes simultaneous failure far less likely.

brain0

Developer

From: Aachen - Germany

Registered: 2005-01-03

Posts: 1,382

Re: RAID or not to RAID

RAID is not complex, it is very simple. Use a RAID1 with two hard drives.

Also, use LVM. It is mandatory for any system you'd like to maintain long-term.