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wiski15b

macrumors regular
Original poster
Apr 20, 2016
118
8
Hey everyone,
Im looking at getting a new drive/drives for internal time machine in my Mac Pro 2010. Ill probably be backing up a few large files (100gb+) so was thinking to maybe RAID 0 them. Trying to decide between the WD Black because its 7200rpm or the Seagate SSHD but I'm not sure if Time Machine will benefit from a hybrid hard drive. Or do you think I should just go cheap and get a WD Blue or 2?

Thanks,
Matt
 
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cruisin

macrumors 6502a
Apr 1, 2014
962
223
Canada
Backups don't really need the speed, as aside from the first backup the hourly backups are much smaller. Also RAID is not a backup, and RAID 0 is terrible as it is actually AID (no redundancy) and double the risk of data failure.

Get the brand you like with decent warranty (all of them break down) and get two of them. Then set them as independent backups and even if one dies you have a spare to keep things running as you get a replacement.
 

Gav2k

macrumors G3
Jul 24, 2009
9,216
1,608
You want a wd red or seagate archive drive. Speed isn't an issue with time machine.
 

maflynn

macrumors Haswell
May 3, 2009
73,682
43,740
Putting a backup drive internally may not be what they call "best practices"
What happens if you knock the computer over, you lose all your hard drives to due to a head crash, or if some sort of failure and a surge occurs that fries the internals.

I think an external drive is a safer option - but that's just me.
 

Juicy Box

macrumors 604
Sep 23, 2014
7,580
8,920
It seems like most people disagree with me, but I think speed is important. Not necessarily for the backing up, but actually using TM.

I was using a slow HDD for TM. There wasn't any issues with it until I went to recover something that was deleted. Trying to go back in time to the date I wanted to recover, then waiting for it to load took a long time.

I was using a really old HDD I had around, so that may have been my issue. If you are buying the current stuff, you will probably be fine for speed.
 

h9826790

macrumors P6
Apr 3, 2014
16,656
8,587
Hong Kong
It seems like most people disagree with me, but I think speed is important. Not necessarily for the backing up, but actually using TM.

I was using a slow HDD for TM. There wasn't any issues with it until I went to recover something that was deleted. Trying to go back in time to the date I wanted to recover, then waiting for it to load took a long time.

I was using a really old HDD I had around, so that may have been my issue. If you are buying the current stuff, you will probably be fine for speed.

I think it's about how often you have to access the TM, if you do that few times day, then speed of course is a problem. However, no matter which HDD, the small files read performance will be very poor anyway. And I don't think it's a good idea to use SSD as backup dive (in both size and cost). I am not sure if SSHD can help improve performance in TM, if it is, then may be it's a more balance between cost and speed.

If only access the TM once every few week / months, then speed sure is not that important. I understand that's a bit frustrated to wait TM respond, but few minutes of waiting for every few months, I don't think it's a problem at all.

Anyway to OP. The WD Red 6T works well in the cMP. Some large size (>4T) HDD's mounting point is a bit different, or may be a bit thicker. They may not mount properly, or may infringe the the PCIe fan / PCIe slot 4. I have this HDD in my Mac Pro for backup purpose. Works very well.
 

phrehdd

Contributor
Oct 25, 2008
4,515
1,467
Here - a great place to investigate various drives : http://www.storagereview.com/reviews

You didn't really give a size that you require for your new drive. The two things I would consider is how robust the drive is and cost. If you only need say 1 tb, then a WD Velociraptor is not a bad way to go. Fast, 5 year warranty and works well. It is a 2.5" 10,000 rpm drive put in a 3.5" sleeve (drives require heat dissipation so the sleeve is needed).

If you require larger drives and find your TM needs to be as bullet proof as possible, consider some Enterprise drives (regular or NAS oriented). As for me, I don't use TM but backups and I find that many of the external small drives are good enough (I rotate them). I use both Seagate and WD. When I had in the past a 'real' Mac Pro, I did similar to you in that I housed internally a back up drive.
 

Juicy Box

macrumors 604
Sep 23, 2014
7,580
8,920
I think it's about how often you have to access the TM, if you do that few times day, then speed of course is a problem. However, no matter which HDD, the small files read performance will be very poor anyway. And I don't think it's a good idea to use SSD as backup dive (in both size and cost).

Good point, I upgraded my TM drive to a new HDD in a USB3 enclosure. It is significantly faster than the old one I was using. I was thinking of trying to find a balance between price and capacity in a SSD for the backup in the future.

I was also thinking of getting a hybrid, but I am not sure there would be a significant benefit for the TM considering I don't use it very often.
 

HDFan

Contributor
Jun 30, 2007
7,302
3,349
You might want to checkout disk failure rates in a real world situation. Backblaze's most recent report of
drive failure rates over a billion hour time usage period and 61,590 drives was just updated yesterday.

https://www.backblaze.com/blog/hard-drive-reliability-stats-q1-2016/

See the first graph below for the 2016 results.

They reported the lowest annual failure rate they have experienced at 1.84%.

Seagate and Western Digital have the highest cumulative (since 2013) failure rates. HGST has the lowest, Toshiba is in the middle. For 2016 their failure rates have been (10.68%), (6.55%), (1.03%), and (3.06%) respectively.

Larger drives (6 and 8 TB) are getting closer in price (per TB) to the 4 TB drives they generally use.

The second graph comes from Ross Lazarus, "a self-described grumpy computational biologist". He analyzed the data using Kaplan-Meier statistics and plots. Data is through 2015 only. (http://bioinformare.blogspot.com.au/2016/02/survival-analysis-of-hard-disk-drive.html).
 

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shaunp

Cancelled
Nov 5, 2010
1,811
1,395
Don't use RAID 0 for anything unless an application specifically needs it, and even then consider RAID 10 instead.

Honestly for backup you don't need this. Just capacity and reliability. Get a good quality drive - get a NAS or archive drive as they are typically designed to run for longer periods than a standard hard drive. As for capacity get the biggest you can realistically afford. Put this into a USB 3.0 enclosure. don't bother with USB 2.0 as it's too slow.
 

Alrescha

macrumors 68020
Jan 1, 2008
2,156
317
Don't use RAID 0 for anything unless an application specifically needs it, and even then consider RAID 10 instead.

Having used RAID 0 in one form or another for most of my computing career, this seems pretty parochial. If you value speed or capacity, RAID 0 is where it is at. Yes, you have twice the chance of failure with two drives in RAID 0 over a single drive. Two times a very small number is still a very small number. One should be informed, not needlessly fearful.

A.
 

shaunp

Cancelled
Nov 5, 2010
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Having used RAID 0 in one form or another for most of my computing career, this seems pretty parochial. If you value speed or capacity, RAID 0 is where it is at. Yes, you have twice the chance of failure with two drives in RAID 0 over a single drive. Two times a very small number is still a very small number. One should be informed, not needlessly fearful.

A.

LOL. I've worked in storage for over 15 years. We avoid RAID 0 because of the potential risks - loose one disk and you are having to restore your data. Why risk the downtime? This is why people moved to RAID 10, so you have speed AND redundancy. In more recent times we've moved to heavily virtualised storage which makes RAID levels redundant to a point, or all flash arrays. Occasionally we get a DBA that insists on RAID 0 because their database really needs it, at which point we say 'yeah okay mate' and then put it on RAID 5 and front it with loads of cache. We then monitor it, and if it needs it then we migrate it on the fly to RAID 10 - we very rarely need to do this as the array is more than capable of delivering what the application needs.

Also, this guy was talking about backup for a home system, using 2 disks at most in the array and backing up over USB. How much extra performance do you think he's going to get versus the potential risk of loosing all his backups?

I'm not fearful, just very well informed. ;o)
 

Alrescha

macrumors 68020
Jan 1, 2008
2,156
317
Why risk the downtime? This is why people moved to RAID 10, so you have speed AND redundancy.

If you are using RAID 0 for backups as the OP suggested, there is no downtime. It is just a backup, and if one needs the capacity then RAID 0 is a perfectly reasonable way to get it. RAID 10 is very nice if you can afford to throw twice the number of drives at your solution.

A.
 
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h9826790

macrumors P6
Apr 3, 2014
16,656
8,587
Hong Kong
In fact, I agree that if I need a single large partition, AND I already have few smaller HDD in hand, AND I can afford the data lost on that large partition (e.g. have reliable backup, or it's already one of the backup). Then RAID 0 is good way to achieve what we want as a normal computer user.

However, since OP didn't state this particular condition. And a single large volume HDD is not that expensive now. I will prefer to have a single large drive to serve as backup.

1) more reliable
2) no need the RAID 0 performance 99% of the time (back up work in the background, faster not necessary give the user any real benefit)
3) consume one less HDD bay
4) the partition works in both OSX, Windows (OSX software RAID won't work in Windows)
5) software RAID may cause crash in Windows if all bootcamp driver installed (my own experience)
 

shaunp

Cancelled
Nov 5, 2010
1,811
1,395
If you are using RAID 0 for backups as the OP suggested, there is no downtime. It is just a backup, and if one needs the capacity then RAID 0 is a perfectly reasonable way to get it. RAID 10 is very nice if you can afford to throw twice the number of drives at your solution.

A.

Why bother with RAID 0 for a home backup? Think about the flow of data and how it will be of benefit. Reads data from a single drive, or at least 1 at a time if multiple are installed. This is an incremental backup, that will either have to scan through the disk to find changes, or if TM is semi-intelligent it will keep a journal, but this will then mean a mix of random and sequential I/O. Either way performance is unlikely to be more than 80-100MB/s, probably less. The data will then be written sequentially to the destination. Any modern disk can keep up with over 100MB/s sequential I/O. RAID 0 will give better write performance, but the application would be unable to use this it is limited by the performance of the reads. Therefore any performance gained by RAID 0 would not be seen in the real world.

As for it 'just been a backup', lots of people say that and then wonder what went wrong when they need that backup. Keep it simple and don't take unnecessary risks and the data will be there when you need it. This is especially true for home users who backup when they can and dont' give it much thought. If you have 2 disks, configure them as RAID1 not RAID0 - you won't notice the performance hit and you are protected against disk failure.

For most home users pick a hard disk that is 1.5 to 2 x the size of the data you want to backup and stick with that. If you have lots of data then buy a NAS and enable the TM feature on this. The NAS will support multiple RAID levels so you can group a few disks together to provide a larger capacity, but stick with RAID 5 as the best compromise. I've been using this method for years and it just works. No drama always reliable.
[doublepost=1463666222][/doublepost]
In fact, I agree that if I need a single large partition, AND I already have few smaller HDD in hand, AND I can afford the data lost on that large partition (e.g. have reliable backup, or it's already one of the backup). Then RAID 0 is good way to achieve what we want as a normal computer user.

However, since OP didn't state this particular condition. And a single large volume HDD is not that expensive now. I will prefer to have a single large drive to serve as backup.

1) more reliable
2) no need the RAID 0 performance 99% of the time (back up work in the background, faster not necessary give the user any real benefit)
3) consume one less HDD bay
4) the partition works in both OSX, Windows (OSX software RAID won't work in Windows)
5) software RAID may cause crash in Windows if all bootcamp driver installed (my own experience)

For some apps RAID 0 is great, although I'd be tempted more by SSD now prices are coming down. It depends upon your app and whether you need lots of bandwidth for sequential workloads or random I/O. lots of HDD's are still best for sequential, but can't compete with SSD for random.
 

Alrescha

macrumors 68020
Jan 1, 2008
2,156
317
Why bother with RAID 0 for a home backup?

Because it gives you the greatest capacity per dollar spent?

You started by saying "Don't use RAID 0 for anything unless an application specifically needs it", and I replied by saying that sounded rather parochial. I think your subsequent posts have made my case for me.

If you do not like RAID 0, by all means do not use it.

A.
 
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shaunp

Cancelled
Nov 5, 2010
1,811
1,395
You started by saying "Don't use RAID 0 for anything unless an application specifically needs it", and I replied by saying that sounded rather parochial. I think your subsequent posts have made my case for me.

If you do not like RAID 0, by all means do not use it.

A.

You shouldn't use any RAID level at all unless if meets the needs of your application. How is that narrow minded? It's industry best practice. RAID 0 is not suitable for home backup. RAID 0 isn't suitable for ANY backup because of the risk of data loss.

I said don't use RAID 0 unless the application needs it. Large sequential workloads would be a case where it COULD be needed. Even then it would be a last resort, as RAID 10 would be a better option. This isn't 'building a case for you', again it's industry best practice. I honestly don't care what you use, but I do care about giving others the correct advice. The only people I see using RAID 0 these days are home users because they can't afford to do it properly. All Flash arrays have made RAID 0 and to some degree RAID 10 irrelevant and that's where the industry has headed when performance matters.
 

Alrescha

macrumors 68020
Jan 1, 2008
2,156
317
How is that narrow minded? It's industry best practice. RAID 0 is not suitable for home backup. RAID 0 isn't suitable for ANY backup because of the risk of data loss.

The use of these absolutes and the insistence on industry standards for the OP's home environment is what strikes me as limited. In other words you appear to be relying on dogma (e.g.: 'RAID 0 bad') rather than actually considering the possibilities.

If "risk of data loss" disqualifies a potential backup solution, then one should not use any drives at all. Clearly magnetic tape is the only solution -- oh wait.

A.
 
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shaunp

Cancelled
Nov 5, 2010
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The use of these absolutes and the insistence on industry standards for the OP's home environment is what strikes me as limited. In other words you appear to be relying on dogma (e.g.: 'RAID 0 bad') rather than actually considering the possibilities.

If "risk of data loss" disqualifies a potential backup solution, then one should not use any drives at all. Clearly magnetic tape is the only solution -- oh wait.

A.

LOL. It's not an absolute, it's a conclusion from years of experience. I design and implement enterprise level storage and backup solutions for a living. I have seen hundreds of storage arrays and tens of thousands of servers, yet I cannot recall a single instance of anyone implementing RAID 0 in a production environment over the past 10 years. This is across multiple different industries and different storage vendors. The reason virtually nobody does it is because newer storage arrays are fast enough not to need RAID 0 and the risks to data loss are too great. This is not a closed mind, this is reality. The only people I see using it these days are guys in their bedrooms at home. Some small business somewhere may use it, but they will move to something more suitable after they loose data.

So enlighten me, why do you think RAID 0 would benefit the OP's use case? Given that the performance will be limited by reading from a single drive at a time during the backup operation, how will striping across several disks at the back-end help? You could put a million disks in a RAID 0 array as the backup desination and it would only run as fast as data could be read off a single drive by TM. Are you willing to increase his risk of data loss through with no actual performance benefit? Or is it better because it's more complex and you like playing? RAID 1 would be more helpful to him. RAID 0 will give him nothing.

The use of RAID 0 in a backup solution is a bad idea, not the use of disk. A lot of enterprise level solutions now use disk together with deduplication. All of the major products use RAID 5 arrays, none of them use RAID 0. More and more organisations are moving to entirely disk-based solutions, but magnetic tape is still much more widely used. LTO 7 was just released this year and the format is still going strong and probably will be for many years as it's used for archive. We write at least 2 copies to tape to get round the media reliability issues.

So to summerise and to be absolutely crystal clear, RAID 0 is crap. Utter crap. There is no reason to risk data loss when other technologies are faster than RAID 0 and don't have the associated risk. Yes you can get a lot of storage cheaply, but the performance of a handful of SSD's would be better. If you are a home user on an absolute miniscule budget then RAID 0 may help if you are trying to test the I/O of an application but even then I'd say your computer probably isn't quick enough to drive the I/O of more than a handful of disks anyway, and if your workload is random, then SSD would be better.


I'm sure you disagree with all of this, so tell the whole world why you think RAID 0 is such a great idea....
 

Alrescha

macrumors 68020
Jan 1, 2008
2,156
317
LOL. It's not an absolute, it's a conclusion from years of experience.

Yes, I remember:

LOL. I've worked in storage for over 15 years.

So when you got 'into storage', I had been in computing for 25 years. Don't worry, everyone is a newbie at some point.

A.

(done with this thread)
 

shaunp

Cancelled
Nov 5, 2010
1,811
1,395
Yes, I remember:



So when you got 'into storage', I had been in computing for 25 years. Don't worry, everyone is a newbie at some point.

A.

(done with this thread)

No you are not done. Tell me why you think RAID 0 is so great. share your great experience please....

25 years of clueless me thinks.... Enjoy your RAID 0.
 
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