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Mirroring or Time Machine?
- Thread starter zoran
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If you are talking about something like RAID1 mirroring if you accidentally delete a file (or someone or some program deletes/modifies a file) it is gone.
With Time Machine you can recover deleted files and previous versions.
Though personally I'd rather not have all my files and the backups on the same device (at-least it would be different drives so it's not as bad), incase it fails or is damaged.
With Time Machine you can recover deleted files and previous versions.
Though personally I'd rather not have all my files and the backups on the same device (at-least it would be different drives so it's not as bad), incase it fails or is damaged.
RAID is not a backup scheme and should not be considered as such.
If you use a NAS with RAID, I'd also suggest you back up the NAS, in case of hardware failure.
I would not use an external drive (or NAS) that houses my data on one drive and its backup on the other. Too risky.
A NAS is a great product if you are connecting multiple computers to a disk array. IF you have a single computer, then I'd look to a more inexpensive external drive enclosure that also has RAID. It will connect to directly to your computer and be faster since USB (or thunderbolt) is much faster then Ethernet.
RAID with mirroring cannot be considered as such?
You mean if i have a NAS with 2 drive bays, i shouldn't have one drive used for storing files and the other to work as a backup with TimeMachine? Is that what you are saying?
At the moment i have an mid2010 iMac (only with FW800, no TBold or USB3) and a MyBookStudio 1TB where i use a s backup with TMachine. Due to wanting to store 100hours of dv, i wanted to have a NAS with 2 or more bays. On one bay id want to store files (and dv files) while on the other bay, id throw in a large capacity drive in order to backup everything (either stuff from the iMac + the dv video files).
You don't think this would be a wise choice?
Consider this:
What happens if the NAS drive you have suddenly failed or some level of corruption.
What about if you deleted a folder then realized you deleted the wrong folder.
In both cases of Mirroring/RAID you would lose your data where as a more traditional backup strategy you'd recover the data.
RAID gives you redundancy which helps, but it should not to be considered a backup imo.
RAID provides high availability not backup. I have my 2 drive Synology setup with mirroring. It allows me to access everything when a single drive fails. I have external backups of what is stored on there in the event that the entire unit is lost. This could be due to fire, theft, or electrical issues.
You can't have too many backups in different places. I use Time Machine to multiple destinations along with CCC clones. In addition I use Crashplan for offsite.
You can't have too many backups in different places. I use Time Machine to multiple destinations along with CCC clones. In addition I use Crashplan for offsite.
That's what I do.
I have a Time Machine on my DAS, I back that DAS up via CCC onto a different external drive. I also run a CCC backup of my system onto a portable external drive which I take off site.
So I have three backups, one of which is offsite.
time machine
RAID is used for mirroring, but not in a back up sense. RAID is more of a hardware backup than anything else. The goal behind a raid array is that if a disk should fail, its exact replica is still there and the system will continue to function. Years ago, this was found only on servers and mainframes, now its in things as small as laptops. If you delete a file, its gone on both images (or as many images as you may have). RAID is more about uptime than it is about anything having to do with data backup. Also, saves you from catastrophic failure when a drive breaks (it happens quite a bit when a server runs 10K+ rpm drives, happened to me twice in the 10 years I have been using Macs).
Time Machine is a backup on the software side of things. Its like plugging in an external hard drive every few hours/days/weeks and copying your files over to it. Deleting a file today means that last week when time machine backed up, the file was still there, and is not lost.
This thread just reminded me to plug in my external and run time machine. thanks!
RAID is used for mirroring, but not in a back up sense. RAID is more of a hardware backup than anything else. The goal behind a raid array is that if a disk should fail, its exact replica is still there and the system will continue to function. Years ago, this was found only on servers and mainframes, now its in things as small as laptops. If you delete a file, its gone on both images (or as many images as you may have). RAID is more about uptime than it is about anything having to do with data backup. Also, saves you from catastrophic failure when a drive breaks (it happens quite a bit when a server runs 10K+ rpm drives, happened to me twice in the 10 years I have been using Macs).
Time Machine is a backup on the software side of things. Its like plugging in an external hard drive every few hours/days/weeks and copying your files over to it. Deleting a file today means that last week when time machine backed up, the file was still there, and is not lost.
This thread just reminded me to plug in my external and run time machine. thanks!
In either case, individual drives can fail, or the whole NAS device can fail. Depending on how it fails, it can take both the drives down at the same time, so there is always a risk losing both drives at the same time. That's why I wouldn't want to have data and backup on the same device.
Mirroring gets you running quicker in case one of the devices fails. TimeMachine protects you not only against hardware problems, but also against files that are deleted or damaged through user error, software errors, power loss at exactly the wrong moment, or malware. Imagine you use an editor that once a year overwrites a document with nonsense data. With TimeMachine, you can go back to the past and recover an old version.
Time machine also has that recover function, that if a primary drive does fail, you replace it and restore as if nothing every happened... similar to raid, just a little slower.
If I were still using raid arrays, I would honestly consider using both, raid and time machine. I don't think that they have very much space in which their use and scope overlaps.
If I were still using raid arrays, I would honestly consider using both, raid and time machine. I don't think that they have very much space in which their use and scope overlaps.
Its still a good idea to back up your NAS as well
well yes, having multiple backups is always the recommended path.. but lacking resources having a raid 1 has be your TM backup is significantly better than having a single drive be your TM backup
could you please rephrase this, i didnt get it!well yes, having multiple backups is always the recommended path.. but lacking resources having a raid 1 has be your TM backup is significantly better than having a single drive be your TM backup
so what raid 1 does is it creates a exact copy of the one drive onto the other. What this means is that if drive a fails your data will also exist on drive B.
However what Raid (any configuration) does NOT do is create incremental backups.
so your best case scenario would be to have a Raid 10 or 5 (i use 5) box (minimum 4 drives) this will ensure speed and reliability as the raid box will stripe the drives together so no matter which one fails you will still have access... there are many issues with this and you should familiarize yourself with how raid works (start here: http://en.wikipedia.org/wiki/Standard_RAID_levels )
in addition to the raid box, you would ideally have a backup drive or two and a off site backup. Here is how i have done it!
1 Raid box (4hdd 1tb each for a total of 4th in raid 5)
2 4 TB external drives (both backing up my raid box)
1 off site backup which i update manually every month or so.
Now this may be out of your price range... no shame there... But you still need to backup all of your files! so what do you do?
option 1) buy a
time capsule (1 drive) and forget about it. the Time Machine software that comes with your Mac will work with the time capsule to backup your entire computer (minus what you exclude) every hour without any use input (set it and forget it) http://store.apple.com/ca/product/ME177AM/A/airport-time-capsule-2tb?fnode=4d BUT what happens if and when your time capsule fails? well you loose all your backup (not necessarily your existing files on your mac). But what happens if your time capsule fails and you can't afford to replace it and then your mac fails? well you loose all your files... done... gone. (btw this is very very unlikely, but it can happen)option 2) buy a 2 drive raid box like so: http://www.amazon.ca/Buffalo-DriveS...8&qid=1398439470&sr=1-1&keywords=buffalo+raid or something more affordable like so: http://www.amazon.ca/Vantec-3-5-Inc...3?ie=UTF8&qid=1398439419&sr=8-3&keywords=raid
set your 2 drive raid box in Raid 1 and what you get is a exact copy. Now you can use the Time Machine Software to point to this box and use it as a backup destination... what your computer will see is the total capacity of one drive (say you put 2 4tb drives in it, you will only see 4tb worth of capacity as the second drive will be a image of the first) So what if Drive A fails? well you have your data on both drive B as well as the original location (mac). now what if both Drive A and your mac fail at the same time? Well you still have a backup that you can restore from on Drive B....
The reality however is that you get what you pay for in Raid boxes so a relatively good quality raid box will cost more than a Time Capsule and then you need to buy the drives... And like i said it is quite unlikely that both your Time Capsule and your mac will fail at the same time... what i'm trying to say is that the only real reason to buy any kind of Raid box is if you have data that you really want to make sure you don't loose... ( or if you are a bit of a tech nut and want bragging rights
) before i got my raid box i only had a time capsule (i've owned 2 of those one of which is first generation and that is still going strong at my parents home...) that is to say that in my experience they have been quite reliable.... Anyways, hope this helps. good luck.
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Yeah, I'd say this is overkill for most consumer situations (not judging your situation, just saying it's very robust). And you're absolutely right about keeping an offsite backup.
For most people, I think Time Machine with two drives is sufficient. Keep one drive offsite and bring it home for syncing once in a while.
A slightly more robust scenario would be to have two partitions on each drive and keep a bootable clone on each. I don't do that, but if someone is working from home and they need to be able to get back to work immediately, then a bootable clone is important. A bootable clone with Time Machine on the other partition will get a machine up and running immediately with access to data that is at most an hour old.
RAID enclosures are more expensive than non raid. NAS is more expensive than DAS.
I think that using NAS for Time Machine has the benefit of set & forget convenience, but why are you looking at NAS for your file storage? Are you looking to share the files across multiple divides? Looking to set up a private cloud (which is the marketing pitch for the WD products you linked)?
For your stated intent of file storage on one Drive with TM to the second, you might also just take a look at getting two single drive enclosures. You could also look at a two drive enclosure that doesn't do RAID (Just JBOD).
The devices that you linked have features that you have not indicated that you are looking for. They expect to be managed as a NAS, including setting up services and user accounts. If you just want external drives, you can go much simpler and probably less expensive.
Well i don't see any reasons for not going for a NAS compared to a DAS, plus the fact that FW800 (i have the mid2010 iMac remember?) is outdated and will not find a good DAS with it.
I like WD design and philosophy on heat absorption that happens without a fan, just like my iMac!
My main concern regarding WD products is if they are reliable!
I like WD design and philosophy on heat absorption that happens without a fan, just like my iMac!
My main concern regarding WD products is if they are reliable!
very easy to find a direct attach FW800 enclosure from OWC..
Dual Disc 3.5
Dual Disc 2.5 (fanless)
Single Disc 3.5 (Fanless)
Direct Attached is cheaper and easier. I didn't see that you were connecting only an iMac, but that makes DAS even easier as you don't have to worry about moving it around & plugging in the drives.
If you are set on a NAS, Synology is excellent. QNAP also has a lot of fans, nut I've never owned one.
I have some WD external drives. They are perfectly adequate as far as the hardware goes. Not a huge fan of the management software for WD drives - they don't do a great job of keeping up with OS X releases in my experience. Not sure I would trust them on a NAS, which is primarily a software function.
1. Whats exactly their problem on keeping up with OSX releases. They will not support the latest OSX u mean? Please tell me more!
2. Why not trust them?
I wouldn't say they won't support a new release, just that they aren't always very quick to release updates for the major OS releases.
WD makes good drives and OK enclosures, They are a hardware company. NAS is a software function and that's not their main focus.
The NAS Software shouldn't really be OS version dependent for the most part, unless something happens like removing Java Support. What I have seen is a lag on updating the management tools that run on the workstation and let you do things like manage firmware. It's not that big a deal, I wouldn't personally buy a WD NAS, but I wish you well with yours.
you already got a lot of responses about the NAS vs DAS question. the only thing i can contribute is that DAS is faster (in most cases) than NAS, meaning if you set the DAS on a machine that you don't mind running 24/7 and enable file sharing in your LAN you will effectively have a NAS that is better and more robust (faster access) and reliable (no worries about 3rd party software).
when i was deciding NAS vs DAS i spend some time here: http://www.smallnetbuilder.com/nas/nas-charts/view
you max throughput on your LAN (unless you set up link aggregation) is 100MB/s but most cheap-er NAS don't even come close where as a DAS with WD Red drive will do 130MB/S or so..
anyways, good luck