Raid dual internal SSD?

Discussion in 'MacBook Pro' started by marc11, Jan 26, 2013.

  1. marc11 macrumors 68000

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    #1
    Is is worth it? I have one in the main bay and just installed one in the SuperDrive spot. I know the down side of a failure but is there really a big up side? Can I enable the raid with out losing my os and data on my main drive?
     
  2. el-John-o macrumors 65816

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    #2
    You can't enable the RAID without losing your data. You have to wipe the drives. RAID0 anyway (you can build a mirrored, or RAID1 array with one drive with data on it and one blank drive, but not a striped RAID)

    Worth it? I did it, but more for the capacity than the speed. Newegg had the 256GB Crucial M4's on sale so it was about a hundred bucks cheaper to get two 256GB M4's than one 512GB M4. Didn't want to mess with two drives, so by using RAID0 I get one 512GB volume. Read/Write speeds are insanely fast, but in the real world that doesn't matter as much as access times, which don't have significant improvements in a RAID0.

    It really depends on what you do. If you constantly work with large files stored within the SSD's, then yeah, it'll scream. If you don't, it'll still scream, but you aren't likely to NOTICE the difference between one drive or two.

    I'm not at all opposed to it though! I love it for that once in a while time when I need to work with or move a large file around and BAM it's just done... it's insanely fast.. that's all there is to it. In fact, my read speeds are so fast, they actually EXCEED SATA 6Gb/s speeds. That means that my RAID0 configuration is faster than any one, single SATA 6G drive can possibly be!

    There is, of course, it's big drawback. One drive fails, it's all gone. SSD's are very reliable, but it's a myth to say that they are bulletproof. They still fail. In addition to doubling the speed, you are doubling the rate of failure. The solution, IMO, is just good regular backups. I use a Time Capsule, alternatively.. what are you doing with your old factory spinning hard drive? You could always stick that in a cheap $20 USB 3.0 enclosure and use it as a Time Machine backup source. I don't know what year your MBP is, but if you did two 256GB SSD's and had a 500GB Hard Drive (what came stock on my 2012 MBP), then you won't run into a scenario where you don't have enough room for a backup! I'd do a backup every few days with that (or every day, before I got my Time Capsule, I would plug my MBP into the charger at my desk in the evenings, plug in the USB3 drive, and start Time Machine and go to bed! Doesn't take very long, but a 'routine' like that meant it got a daily backup. Though now with a time capsule, it gets hourly backups!)

    So anyway, bottom line, it's up you. It'll scream, but I wouldn't suggest doing it unless you have a 'backup plan' (no pun intended, hehe).

    Also, bear in mind the drives need to be the same size. If they aren't, you'll lose some capacity. I'm not sure if Mac OS will build the RAID or not anyway, but some software RAID systems will. If they do, say you take a 512GB SSD and a 256GB SSD, you'll end up with a 512GB RAID. The reason is, it'll take your 256GB SSD, and then only 256GB worth of the other drive. You may be able to partition it though, and have a 512GB RAID in that situation, along with a separate 256GB partition, but at a hit in performance. It's just easier to have two drives of the same size!
     
  3. jav6454 macrumors P6

    jav6454

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    Depends on the type of RAID you use. RAID 0 will always be faster but if either one drive fails, so long info. RAID 1 on the other hand is not fast and is just redundancy. Take your pick.
     
  4. marc11 thread starter macrumors 68000

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    #4
    Thanks. I am using a late 2101 15 inch MBP. Performance was one though but also I thought it would be easier to just have one large volume.

    I am well backed up with time ,machine, backbpaze and monthly clones.

    ----------

    Right I know about the failure risk but really that risk is there with a single drive too which is why have multiple back ups.
     
  5. el-John-o macrumors 65816

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    #5
    Then it sounds to me like you are a perfect candidate for RAID0 (called a 'striped RAID' in disk utility). You'll get a bump in performance, a bump in capacity, plus a bump in cool factor ;)

    I'd recommend getting the exact same drive you already have if possible though. Each drive will only operate as fast as the slowest drive, so if you end up buying a slower drive you'll slow it down, if you buy a faster drive; it won't matter! Just easiest to buy the same drive, same size, same specs.
     
  6. marc11 thread starter macrumors 68000

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    #6
    Thanks. Appreciate the insight. I'm waiting on my FireWire 800 enclosure for my spinning drive then I will raid 0 the two ssds. They are the same make and sizes should be a cake walk then to CCC my data back to the cloned drives.
     
  7. el-John-o macrumors 65816

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    #7
    He was also referring to RAID1 which helps reduce the risk of losing data, both drives in that case have the exact same data on them, so if one fails, just replace it and you won't lose anything. But that's not what you are after here, I take it.

    Also, just so you're aware, the failure rate of a RAID0 array and the failure rate of a single drive are not the same. Statistically, you are doubling your chances of a failure. Hard disks fail at a rate of 7% per year (not sure about the stats on SSDs, but bear with me). So with a two hard disk RAID0 array, you have now TWO disks with a 7% fail rate, and if one fails, they both lose everything. So you DO increase the risks of failure.

    But it sounds like you have a good backup solution, so as long as it's frequent, it shouldn't be a problem.
     
  8. jav6454, Jan 26, 2013
    Last edited: Jan 26, 2013

    jav6454 macrumors P6

    jav6454

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    #8
    If you have muliple backups then do a RAID 0 configuration using SSDs.
     
  9. el-John-o macrumors 65816

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    #9
    Any particular reason for using FW800? You can get faster USB 3.0 enclosures for like 20 bucks. (Granted, you aren't likely to saturate even FW800 with a spinning notebook drive).

    You can also use disk utility to clone the drives, btw. It's built right in to OSX and works great!
     
  10. marc11 thread starter macrumors 68000

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    #10
    Right I know its not one to one on the failure risk. My point was any drive can fail at anytime and lose data which is why I am pretty religious about back ups.

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    I do not have USB 3.0 and I want to daisy chain this drive off my other FireWire drives for other uses.
    I already own CCC so its easy for me.
     
  11. el-John-o macrumors 65816

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    #11
    Why? He won't get any improvement in performance (potentially a mild reduction), and he'll lose half the storage capacity of his combined drives. Storage comes at a premium with an SSD, one of the advantages of running RAID0 is combining drives to make one volume with a larger capacity. With his regular backups, he's got data redundancy covered.

    Doy. Sorry, wasn't thinking, you said it was a 2011!
     
  12. marc11 thread starter macrumors 68000

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    #12
    Yep I was 5 months behind the update.
     
  13. jav6454 macrumors P6

    jav6454

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    #13
    I meant RAID 0. You do realize that was my point given he had several backups.
     
  14. el-John-o macrumors 65816

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    #14
    Also, smart move on the backups. I've even seen a RAID1 configuration of two server class drives fail. Was a member of my church, he had a RAID1 configuration of 1TB drives. One drive failed, so he shipped it off for warranty. The next day, the other drive failed! Good thing he had an offsite backup as well! (AND a backup to a THIRD 1TB drive that he attached externally for weekly snapshots!)

    I'm a believer in "3, 2, 1". At least for the really important stuff. 3 backups, 2 types of media, and 1 offsite (though I'm not as much a sticker on the 2 types of media anymore, was more relevant years ago).

    In my case, I have my Time Capsule backup for most of my stuff, I also have a larger library of stuff (DSLR images, etc.) on a RAID1 NAS (Well actually technically it's RAIDZ in ZFS, but it functions similar to RAID1 in that it mirrors to two drives). So that's, in each case, 2 of everything. The off-site is a cloud backup solution, though I'd like to find one that would run on my server, and would backup my RAID array in the server, and backup the contents of the Time Capsule. All of my data is ALSO stored on always on 24/7 hardware, so no reason to have it running on my desktop or laptop which are not always on!


    Yeah I was scratching my head on the backups comment. Gotcha. I thought maybe that was the case, I looked at that post and went 'huh'? Sorry about that.
     

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