Backup strategy - RAID 1 vs. RAID 5

[JW310]

Originally posted by: SnoMunke
RAID is not a secure backup plan??????? Tell that to your bank, your credit card company, the IRS, Yahoo, MSN, Google, etc.

RAID is the most secure way of maintaining data integrity. Period. End of story.

Firewire external hard drive???? Single point of failure...

Zepper, not sure what you do, but I WORK as as computer engineer with servers, NAS, etc, etc. I am quite sure I know what I am talking about...BUT....if you think I am wrong, go ahead and ask anyone else in this forum what they think about the security of RAID.

Riiiight... and I'm sure RAID is such a secure backup plan that "your bank, your credit card company, the IRS, Yahoo, MSN, Google, etc." don't need to keep separate backup copies of data on backup tapes or whatever :roll:

JW

 

[SnoMunke]

Has anyone ever thought about the time it would take to restore data from tape to a multiple TB storage array?

I just finish working with EMC2 (www.emc.com) on a proposal for a 16 TB storage array to hold a few billion pages of a government library. We are not even using tape backup since disc drives are cheap and it is easier to restore data in a RAID array that using tape.

Zepper,

Backing up to a single HDD disc is a single point of failure...it fails you lose your data. RAID (1 and 5) can handle at least a single point of failure without losing data, more depending if you are using RAID 6 or 10 or mutilple controllers with multiple HDDs.

I will agree with you that backing up a RAID array does give another layer of backup.

By the way, what do you do in the I.T. industry?

Gnomepunk,

I had a RAID 0 array, change controllers, didn't lose any data. So what is your point about losing a controller? Data is still there.

JW310,

In light of your sarcastic remark, I thought it prudent to instruct you that proper, grammatical English requires the use of "doesn't" instead of "don't".

 

[n0cmonkey]

Originally posted by: SnoMunke
Has anyone ever though about the time it would take to restore data from tape to a multiple TB storage array?

I just finish working with EMC2 (www.emc.com) on a proposal for a 16 TB storage array to hold a few billion pages of a government library. We are not even using tape backup since disc drives are cheap and it is easier to restore data in a RAID array that using tape.

Zepper,

Backing up to a single HDD disc is a single point of failure...it fails you lose your data. RAID (1 and 5) can handle at least a single point of failure without losing data, more depending if you are using RAID 6 or 10 or mutilple controllers with multiple HDDs.

I will agree with you that backing up a RAID array does give another layer of backup.

By the way, what do you do in the I.T. industry?

Gnomepunk,

I had a RAID 0 array, change controllers, didn't lose any data. So what is your point about losing a controller? Data is still there.

What do you do in the case of a fire? Or a virus gets loose and deletes all the data on your NAS?

RAID is not a backup solution, it's a redundancy solution. The R doesn't stand for backup, no matter how much you try.

 

[Zepper]

I see that one fellow here uses tape for backup and is happy he did - but no one else here is arguing for a tape backup on large storage systems. But in mission critical situations, you do need some kind of off-site backup plan for the worst-case scenario. I wish you luck if you continue to fly without one, you'll need it...

.bh.

 

[Rubycon]

RAID is about as good of a backup plan as is slamming your hurst up to PARK to stop!

Silly bunny!

🙂

 

[rqle]

What people used RAID as backup? I never knew that. What i learn from our company computer's here is it mainly used for drive intergity on site incase drive failure that can easily be replace. And all our backup is set up with an multiple off-site backup solution (raid included, but still off-site).

I'm just an intern but let me ask my supervisor about Raid as backup, i think am gonna get a ear full about how raid is used for drive intergity on-site, RAID setup off-site is a backup itself.

 

[FlyingPenguin]

Why is this a discussion?

RAID is ONE METHOD of disaster protection. Technically it is NOT a backup strategy.

RAID won't help if your SQL database becomes corrupt and you only realize it weeks later (been there, done that).

RAID won't help if your array becomes corrupt (the whole mirror will become corrupt - been there, done that).

RAID won't help if your building burns down, floods, or your computer gets stolen.

I'd rather see a client doing daily backups (preferably to DVD with weekly archives that are taken off-site) and no RAID, than only RAID with no backups.

 

[Some1ne]

What do you recommend?

RAID-5. RAID-1 is just silly, half the space and almost none of the performance gains of other RAID levels.

 

[JW310]

Originally posted by: SnoMunke
Has anyone ever thought about the time it would take to restore data from tape to a multiple TB storage array?

I just finish working with EMC2 (www.emc.com) on a proposal for a 16 TB storage array to hold a few billion pages of a government library. We are not even using tape backup since disc drives are cheap and it is easier to restore data in a RAID array that using tape.

Zepper,

Backing up to a single HDD disc is a single point of failure...it fails you lose your data. RAID (1 and 5) can handle at least a single point of failure without losing data, more depending if you are using RAID 6 or 10 or mutilple controllers with multiple HDDs.

I will agree with you that backing up a RAID array does give another layer of backup.

By the way, what do you do in the I.T. industry?

Gnomepunk,

I had a RAID 0 array, change controllers, didn't lose any data. So what is your point about losing a controller? Data is still there.

JW310,

In light of your sarcastic remark, I thought it prudent to instruct you that proper, grammatical English requires the use of "doesn't" instead of "don't".

Well, hot damn, one learns something new every day. Thanks for the English lesson, professor.

JW

 

[Vegito]

My system consist of multi layer backup system

EMC CX500 RAID file server. Replicates via 150mbps metro ethernet to DR site to another EMC CX500 file server.

Data are backup using MS Volume Shadow Copy every 1 hour

Data are also backup using Backup 2 Disk as mentioned, yes disk are cheap

Data are archived and backup on SDLT tape library every night and moved off site

Yes, if the EMC system goes bad, I can cut over to the DR site. If data is ERASED by accident, I can restore off shadow copy or restore off backup to disk.

If the whole site burns down, RAID 5 is not going to help me. Only my DR & tapes.

I hope your EMC is fire / water proof.. if I drop a nuke on your 16 TB system, I hope you got tapes somewhere.. Unless your 16tb system is in multi locations.

BTW Thanks, I own a lot of emc stocks... thanks for the help there..

 

[SnoMunke]

I agree...traditionally RAID is not a backup strategy. HOWEVER, with "spinning discs" now becoming much cheaper than tape, most companies run massive NAS arrays linked to other massive NAS arrays. In doing that, they 1. always have data available, 2. they meet the "offsite" requirement.

Again, I will reinterate. Most companies do NOT backup TBs of data to tape. The recovery time is just too long (and of course the tape degregates faster than HDDs).

Large organizations are now doing "backups" of RAID arrays to other RAID arrays. Data never leaves a "spinning disc".

My point to all this tirade is telling someone to back up to a single USB drive (or even two USB drives) and "all will be fine", is misleading. The backup USB drive can fail just as easily as a HDD in a RAID array...and then there nothing (other than the operational data) to restore to the backup USB drive. With RAID (1,5,6,10) the operational data IS both the operational data AND the backup.

In addition, a single USB backup drive can be just as easily corrupted or infected with a virus as a RAID array or NAS can be.

The cutting edge of technology is using "spinning discs" only. Tape and DVDRs are not an option.

Back to the original subject of this thread... oktane was asking about RAID and NAS as a FAST and reliable backup solution...hence my suggestions to him. Even RAID 1, as silly as it is (I run RAID 1 by the way), meets oktane's requirements. Backing up to a single USB HDD is not fast...neither is burning DVDRs.

 

[SnoMunke]

Vegito,

Sounds like you are on the cutting edge. EMC is now starting to recommend setting up offsite "bunker" storage (NAS) that can be used to restore data versus using tape... HDDs are much cheaper and faster to restore from than tape.