Systems for Automatic Duplication
So I’ve convinced you to store your files on a volume that has automatic duplication capabilities...now the question is, which one should you buy?
There are more solutions available than ever, and fortunately there are some great options for the home user that don’t require an IT genius to set up.
My recommendation is for a RAID 1 Mirroring setup.
I think RAID 1 offers the best protection from the most common hard drive failures. That’s because most RAID 1 products allow you to access your data after a single hard drive failure. That allows you to make an immediate backup of your files to ensure you have an up-to-date copy, and it gives you many options for restoring your redundant copy.
There are many vendors for RAID 1 products, but Western Digital and LaCie stand out as having solutions that are priced for the home user, and are easy to set up and maintain.
Western Digital offers the My Book Studio Edition II. LaCie offers several solutions, with the Hard Drive MAX being the most attractively priced.
Between the two, the Western Digital product looks like the more attractive choice to me.
My prime motivator is price...the Western Digital product is about $100 cheaper than similar capacity LaCie models, which adds up quick if you need a lot of storage.
But I also like the fact that Western Digital is a larger company that is likely selling more units...and I think a larger user base for a product is always a good thing. I have no way of knowing if that really will make it a better product...it’s just a gut feeling. I haven’t used either product, so I’m just going by specs and company reputation.
Before you buy any storage solution, you should run it through my Storage Litmus Test:
Do you know how an successfully operate it successfully 100% of the time?
Read the manuals online before you buy and ask yourself if you know you can successfully operate it. If you don’t feel confident that you can, then don’t buy that solution.(And if you already have a solution, read the manuals now and see if it passes or fails the test.)
Bad Solutions and Non-Solutions
In our poll a few weeks back, several people said they are using RAID 0 Striping to protect their files. That’s bad news because RAID 0 provides less protection than a single hard drive. RAID 0 works by splitting up a file so half of it goes on one drive, and the other half goes to a second drive. If one hard drive fails, you lose all of your files. Even worse, if the data that tracks how the files are split up becomes corrupted, you lose access to all your files. RAID 0 is about speed, not protection. Don’t use it for protection!
RAID 5 is another solution some people are using. It’s been the darling of the IT industry for a long time, but I think it’s playing with fire.
About a year ago, a client had a RAID 5 fail. After about 4 weeks without access to their drives and considerable expense, they were able to recover all their data...and this was with a top-end system. They got lucky...they could have lost it all...and luck is not a protection strategy. Last I talked to them, they were investigating a RAID 1 system.
If you want to get techie about it, check out Why RAID 5 stops working in 2009.
The Drobo is also subject to the many of RAID 5’s shortcommings since it typically uses parity data to create a virtual duplicate. That means that if a second drive fails before a rebuild is complete, you can lose all of your data. I did one tweet recommending the Drobo, but I’ve since become jaundiced on it, and I’ve removed the tweet. I think RAID 1 is a much safer solution than the Drobo.
If you are using RAID 5 or a Drobo, I’d replace it with a RAID 1 immediately. Not having to rebuild a disk from parity data is a good thing.
What does Rich do?
What do I do? I use a custom RAID 1 solution that I’ve assembled to work on Mac servers. I use SoftRAID to make mirrored copies to two separate hard drives. SoftRAID doesn’t use proprietary formats, so both copies of a volume are readable on any computer...I don’t need a RAID card or enclosure to read them in event of a failure. I use Sonnet DP500 SATA enclosures with Sonnet SATA cards, and various brands of SATA hard drives. The servers run 24/7/365 and are hooked up to a battery backup to protect against short power outages. In this configuration, with dozens of hard drives, I have a drive or two fail every year, but I have not lost any data, and I have been able to keep accessing my files while the mirrored drives rebuilt. It is very fault tolerant, very simple, and has proven very reliable.
My solution does basically the same thing as the Western Digital and LaCie products, just on a larger scale.
Whatever solution you choose, remember that an automatic file duplication system like a RAID 1 is NOT a backup! It will not protect against catastrophic failures, i.e. when your hard drive is lost, stolen, or destroyed. It is meant to protect you as you are working, which is the time in between backups. It also makes it less likely you’ll need to use a backup to restore a hard drive, which can be a time consuming process (And you typically lose some files, since backups are almost always out-of-sync with your hard drive).
Buy one today, before your single hard drive fails.
There are more solutions available than ever, and fortunately there are some great options for the home user that don’t require an IT genius to set up.
My recommendation is for a RAID 1 Mirroring setup.
I think RAID 1 offers the best protection from the most common hard drive failures. That’s because most RAID 1 products allow you to access your data after a single hard drive failure. That allows you to make an immediate backup of your files to ensure you have an up-to-date copy, and it gives you many options for restoring your redundant copy.
There are many vendors for RAID 1 products, but Western Digital and LaCie stand out as having solutions that are priced for the home user, and are easy to set up and maintain.
Western Digital offers the My Book Studio Edition II. LaCie offers several solutions, with the Hard Drive MAX being the most attractively priced.
Between the two, the Western Digital product looks like the more attractive choice to me.
My prime motivator is price...the Western Digital product is about $100 cheaper than similar capacity LaCie models, which adds up quick if you need a lot of storage.
But I also like the fact that Western Digital is a larger company that is likely selling more units...and I think a larger user base for a product is always a good thing. I have no way of knowing if that really will make it a better product...it’s just a gut feeling. I haven’t used either product, so I’m just going by specs and company reputation.
Before you buy any storage solution, you should run it through my Storage Litmus Test:
Do you know how an successfully operate it successfully 100% of the time?
Read the manuals online before you buy and ask yourself if you know you can successfully operate it. If you don’t feel confident that you can, then don’t buy that solution.(And if you already have a solution, read the manuals now and see if it passes or fails the test.)
Bad Solutions and Non-Solutions
In our poll a few weeks back, several people said they are using RAID 0 Striping to protect their files. That’s bad news because RAID 0 provides less protection than a single hard drive. RAID 0 works by splitting up a file so half of it goes on one drive, and the other half goes to a second drive. If one hard drive fails, you lose all of your files. Even worse, if the data that tracks how the files are split up becomes corrupted, you lose access to all your files. RAID 0 is about speed, not protection. Don’t use it for protection!
RAID 5 is another solution some people are using. It’s been the darling of the IT industry for a long time, but I think it’s playing with fire.
About a year ago, a client had a RAID 5 fail. After about 4 weeks without access to their drives and considerable expense, they were able to recover all their data...and this was with a top-end system. They got lucky...they could have lost it all...and luck is not a protection strategy. Last I talked to them, they were investigating a RAID 1 system.
If you want to get techie about it, check out Why RAID 5 stops working in 2009.
The Drobo is also subject to the many of RAID 5’s shortcommings since it typically uses parity data to create a virtual duplicate. That means that if a second drive fails before a rebuild is complete, you can lose all of your data. I did one tweet recommending the Drobo, but I’ve since become jaundiced on it, and I’ve removed the tweet. I think RAID 1 is a much safer solution than the Drobo.
If you are using RAID 5 or a Drobo, I’d replace it with a RAID 1 immediately. Not having to rebuild a disk from parity data is a good thing.
What does Rich do?
What do I do? I use a custom RAID 1 solution that I’ve assembled to work on Mac servers. I use SoftRAID to make mirrored copies to two separate hard drives. SoftRAID doesn’t use proprietary formats, so both copies of a volume are readable on any computer...I don’t need a RAID card or enclosure to read them in event of a failure. I use Sonnet DP500 SATA enclosures with Sonnet SATA cards, and various brands of SATA hard drives. The servers run 24/7/365 and are hooked up to a battery backup to protect against short power outages. In this configuration, with dozens of hard drives, I have a drive or two fail every year, but I have not lost any data, and I have been able to keep accessing my files while the mirrored drives rebuilt. It is very fault tolerant, very simple, and has proven very reliable.
My solution does basically the same thing as the Western Digital and LaCie products, just on a larger scale.
Whatever solution you choose, remember that an automatic file duplication system like a RAID 1 is NOT a backup! It will not protect against catastrophic failures, i.e. when your hard drive is lost, stolen, or destroyed. It is meant to protect you as you are working, which is the time in between backups. It also makes it less likely you’ll need to use a backup to restore a hard drive, which can be a time consuming process (And you typically lose some files, since backups are almost always out-of-sync with your hard drive).
Buy one today, before your single hard drive fails.
posted by Rich Seiling at
4/06/2009
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2 Comments:
Thank you for this post. I have been somewhat confused about which RAID file duplication system to use since I am looking to automate this task. Right now, I am the system manually copying to 3 duplicate drives and it takes up way to much of my time.
Is there software similar to SoftRAID for PC users?
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