Trying Hard To Try Hard Drives
February 14, 2013 7:28 PM Subscribe
What's the scoop on high capacity hard drives these days - questions about RAID and OSX 10.6.8.
I've been a bad boy - or busy boy - and have not been paying attention to anything computer related for the past couple of years. As a result I'm feeling exceptionally ignorant and the little research I've done recently seems contradictory.
My current set up is a late 2009 i7 iMac running 10.6.8., and I have a 4 bay external hard drive enclosure with two 2TB drives in RAID 1 where I keep my music (i.e. I'm only using two bays out of the four, each bay with 2TB drive). Controlled through iTunes.
The external enclosure at the time of purchase was rated for taking maximum 2TB drives, so I did the 2 x 2TB in RAID1. BUT that was just because 2TB was the maximum on a single drive that was available.
These days we have 4TB drives, such as this HGST 4TB Deskstar 3.5" SATA III Internal Desktop Hard Drive Kit
My music collection is always expanding, and I'd love to buy 2 4TB drives such as the above. Questions:
1) Is there any issue formatting a 4TB drive in OS X 10.6.8 (as I understand it, there is/was some in Windows)
2) Any problem having two 4TB in a RAID1
3) Can I use my current external hard drive enclosure that was rated to take maximum 2TB size drives and using 4TB drives instead? I cannot think off the top of my head why 4TB drives would represent a problem - but that is most likely due to my ignorance.
4) Do I have to get a new enclosure rated specifically for handling 4TB drives?
I've been a bad boy - or busy boy - and have not been paying attention to anything computer related for the past couple of years. As a result I'm feeling exceptionally ignorant and the little research I've done recently seems contradictory.
My current set up is a late 2009 i7 iMac running 10.6.8., and I have a 4 bay external hard drive enclosure with two 2TB drives in RAID 1 where I keep my music (i.e. I'm only using two bays out of the four, each bay with 2TB drive). Controlled through iTunes.
The external enclosure at the time of purchase was rated for taking maximum 2TB drives, so I did the 2 x 2TB in RAID1. BUT that was just because 2TB was the maximum on a single drive that was available.
These days we have 4TB drives, such as this HGST 4TB Deskstar 3.5" SATA III Internal Desktop Hard Drive Kit
My music collection is always expanding, and I'd love to buy 2 4TB drives such as the above. Questions:
1) Is there any issue formatting a 4TB drive in OS X 10.6.8 (as I understand it, there is/was some in Windows)
2) Any problem having two 4TB in a RAID1
3) Can I use my current external hard drive enclosure that was rated to take maximum 2TB size drives and using 4TB drives instead? I cannot think off the top of my head why 4TB drives would represent a problem - but that is most likely due to my ignorance.
4) Do I have to get a new enclosure rated specifically for handling 4TB drives?
Oh, I just thought of the possibility that you might be able to get a new firmware for your enclosure that supports 3TB+ disks. It's worth a look.
posted by zsazsa at 9:09 PM on February 14, 2013
posted by zsazsa at 9:09 PM on February 14, 2013
Response by poster: Thanks, zsazsa. Hmm, I guess new enclosures it is then... any recommendations for reliable ones? I looked at newegg, but there don't seem many choices at reasonable cost with enough reviews etc.;
I guess it's the nature of tech that as HDD capacities grow, one has to keep buying enclosures :(
posted by VikingSword at 9:23 PM on February 14, 2013
I guess it's the nature of tech that as HDD capacities grow, one has to keep buying enclosures :(
posted by VikingSword at 9:23 PM on February 14, 2013
Since you would need to buy the drives anyway, theres no harm in buying them and trying them in your current enclosure.
If they don't work, you have to buy a new enclosure which you were going to buy anyway*.
Yes there is a difference at 2+TB. MBR vs Others (windows is GPT for 2TB+, not sure on others). On windows/linux MBR/GPT mainly matters for booting. (bios can only boot 2tb, EFI for booting 2.2TB+).
posted by TheAdamist at 9:42 PM on February 14, 2013
If they don't work, you have to buy a new enclosure which you were going to buy anyway*.
Yes there is a difference at 2+TB. MBR vs Others (windows is GPT for 2TB+, not sure on others). On windows/linux MBR/GPT mainly matters for booting. (bios can only boot 2tb, EFI for booting 2.2TB+).
posted by TheAdamist at 9:42 PM on February 14, 2013
Best answer: Drives of that size use larger data sectors that older controller chips don't know how to handle.
This is mostly untrue. Although the sectors that physically exist on the disk are 4KiB rather than the traditional 512 bytes, most large drives still transfer data in 512 byte logical sectors; from the controller's point of view there is basically no difference between most 4KiB-sectored drives and earlier 512-byte sectored drives. Drives that use 4KiB logical sectors only, and don't do the 512-byte logical sector emulation thing, are still quite rare.
bios can only boot 2tb
Again, not necessarily true. BIOS looks for something that seems to be boot code in the very first sector of a drive of any size, and runs it if it finds it. Even a disk partitioned using GPT rather than MBR partitioning has a "protective" MBR in the very first sector, and there's room in that for the traditional quantity of boot code. It's quite feasible for that first block to contain code that transfers control to the first sector of a GPT boot partition in the same way EFI would do. For example, GRUB will do this if installed on a GPT disk in a non-EFI computer, and GRUB can chain-load any other boot loader you like.
The only gotcha with >2TiB disks on Macs, as far as I know, is that if they expose the usual 512-byte logical sectors on their drive to controller interface, you can't use MBR partitioning to create partitions beyond the first 2TiB. But MBR partitioning always was a hideous and loathsome scheme, is now well past its use-by date, and should be avoided if possible. GPT partitioning is much tidier, much more flexible, shouldn't need to be superseded in order to cope with any drive likely to appear in the next several centuries, and works fine on Macs, Windows post-Vista, and any variant of Linux you're likely to find inside a modern NAS.
posted by flabdablet at 10:32 PM on February 14, 2013 [2 favorites]
This is mostly untrue. Although the sectors that physically exist on the disk are 4KiB rather than the traditional 512 bytes, most large drives still transfer data in 512 byte logical sectors; from the controller's point of view there is basically no difference between most 4KiB-sectored drives and earlier 512-byte sectored drives. Drives that use 4KiB logical sectors only, and don't do the 512-byte logical sector emulation thing, are still quite rare.
bios can only boot 2tb
Again, not necessarily true. BIOS looks for something that seems to be boot code in the very first sector of a drive of any size, and runs it if it finds it. Even a disk partitioned using GPT rather than MBR partitioning has a "protective" MBR in the very first sector, and there's room in that for the traditional quantity of boot code. It's quite feasible for that first block to contain code that transfers control to the first sector of a GPT boot partition in the same way EFI would do. For example, GRUB will do this if installed on a GPT disk in a non-EFI computer, and GRUB can chain-load any other boot loader you like.
The only gotcha with >2TiB disks on Macs, as far as I know, is that if they expose the usual 512-byte logical sectors on their drive to controller interface, you can't use MBR partitioning to create partitions beyond the first 2TiB. But MBR partitioning always was a hideous and loathsome scheme, is now well past its use-by date, and should be avoided if possible. GPT partitioning is much tidier, much more flexible, shouldn't need to be superseded in order to cope with any drive likely to appear in the next several centuries, and works fine on Macs, Windows post-Vista, and any variant of Linux you're likely to find inside a modern NAS.
posted by flabdablet at 10:32 PM on February 14, 2013 [2 favorites]
Response by poster: Again, thanks for the info... see what I mean? Some sources say one thing, other sources something else... which is why I came to AskMefi to clear things up. I guess indeed there is no harm in trying the new drives in the old enclosure, and in the worst (and most likely) case, I'll have to spring for a new enclosure. Btw., is ZFS happening or are we riding on HFS+ for all eternity (of course, WinFS didn't happen either)... I suppose it won't matter since the drives won't last forever anyhow.
posted by VikingSword at 11:11 PM on February 14, 2013
posted by VikingSword at 11:11 PM on February 14, 2013
Best answer: ZFS was never really all that supported on OS X, so don't hold your breath (though there are evidently third-party drivers for it). so, unless you want to switch to Solaris..
Other World Computing makes some pretty high quality drive enclosures. link goes to the 4-bay version and they have 2-bay ones available too, with disks or without. they will sell you a guaranteed-to-work 16TB raw storage unit so you don't have to bother with sourcing disks or anything. you certainly can bring your own disks if you want to; the enclosures are a bit picky and you need to avoid "green" disks (usually any 7200RPM-style one will be fine). (FWIW, don't use "green" disks in any sort of a RAID anyway - the aggressive power management stuff on the disk itself tends to trip up RAID software unless it happens to know about it and they usually don't.) additionally, there's no real reason why you can't continue to use the old enclosure too.. i'd even go as far as doing up a 2-bay 2x4TB RAID-0 new enclosure and then stuff two more 2TB disks in the old one as two mirrors or a RAID 10, and then have something (SuperDuper! maybe) clone nightly.
another note: FWIW, Disk Utility will make GPT partitions by default. let it do the default and you should not have issues.
posted by mrg at 7:01 AM on February 15, 2013
Other World Computing makes some pretty high quality drive enclosures. link goes to the 4-bay version and they have 2-bay ones available too, with disks or without. they will sell you a guaranteed-to-work 16TB raw storage unit so you don't have to bother with sourcing disks or anything. you certainly can bring your own disks if you want to; the enclosures are a bit picky and you need to avoid "green" disks (usually any 7200RPM-style one will be fine). (FWIW, don't use "green" disks in any sort of a RAID anyway - the aggressive power management stuff on the disk itself tends to trip up RAID software unless it happens to know about it and they usually don't.) additionally, there's no real reason why you can't continue to use the old enclosure too.. i'd even go as far as doing up a 2-bay 2x4TB RAID-0 new enclosure and then stuff two more 2TB disks in the old one as two mirrors or a RAID 10, and then have something (SuperDuper! maybe) clone nightly.
another note: FWIW, Disk Utility will make GPT partitions by default. let it do the default and you should not have issues.
posted by mrg at 7:01 AM on February 15, 2013
Response by poster: Thank you everyone. I think I'll give it the old college try with sticking 4TB drives in another RAID enclosure I have, before buying a new one. This enclosure is the DataTale 2-Bay RAID System RS-M2QO. Now, if only the price of 4TB drives would drop...
posted by VikingSword at 5:39 PM on February 15, 2013
posted by VikingSword at 5:39 PM on February 15, 2013
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2) I don't see why not.
3/4) Unfortunately, you'll probably have to find a new enclosure that specifically supports 3TB+ disks. Drives of that size use larger data sectors that older controller chips don't know how to handle.
posted by zsazsa at 8:57 PM on February 14, 2013