Time Machine on OSX Server: RAID or multiple destinations?

Discussion in 'Mac OS X Server, Xserve, and Networking' started by edanuff, Dec 10, 2016.

  1. edanuff macrumors 6502

    Oct 30, 2008
    I'm using a Mac Mini running OSX Server as a home server running the Time Machine service to handle backups from several Macs. I'm looking to expand the storage and I'm considering something like the Thunder Bay 4. Should I use RAID to best make use of this or can I just set up each drive as a Backup Destination in Time Machine and it'll handle making use of the right disk to store the backups? I've gone through the Server help documentation but it doesn't seem to be too descriptive of what the options might be.
  2. belvdr macrumors 603

    Aug 15, 2005
    I don't think Time Machine is that intelligent.
  3. Weaselboy Moderator


    Staff Member

    Jan 23, 2005
    From this it looks like you can setup multiple destinations then on the individual client machines select which destination (disk) you want to use in the Time Machine settings.
  4. anotherdudeontheinterweb macrumors newbie

    Nov 13, 2016
    I can't speak to what OS X server will enable, but the multiple hardddrives on a mini will definitely work as that is what I have running.

    I have a single Mac mini running sierra (not server) with two 5TB USB drives attached. Each drive is partitioned multiple times so that I have one partition per Mac (6 in total) to be backed up. Each mac backs up to a single partition and each partition is roughly double the size of the Mac that backs up to it. This allows each Mac to keep copies of older files and also prevents the macs for competing for backup space within a partition. File sharing is enabled on the mini so that those drives are available via my home network.

    On each Mac I went into time machine and set it up to backup to the appropriate partition on the mini. Had I wished to I could have set them up to back up to multiple drives so that I had two copies of each backup. This rollover function is standard in time machine.

    Now every computer in my house makes its time machine backups via wifi to the mini. The only downside is that I do not have any centralized method of ensuring all machines are backed up. If a time machine backup fails for any reason, the error message is sent only to that Mac.

    Perhaps the time machine functionality in OS X server improves upon that? I'm curious what other benefits, if any, would result from using the server app.

    Hope this is helpful.
  5. belvdr macrumors 603

    Aug 15, 2005
  6. DJLC macrumors 6502a


    Jul 17, 2005
    Mooresville, NC

    If you want to segregate different Macs onto different drives and/or you want Time Machine to maintain backups on more than one drive (ie., multiple copies of the backup), use them as individual disks.

    If you just want your backup drive to be redundant and only want your Macs to maintain one backup on one drive, I'd set up a mirror (RAID1).
  7. hfg macrumors 68040


    Dec 1, 2006
    Cedar Rapids, IA. USA
    My setup is using the RAID solution for a single storage pool. I have my Mac Mini running Server connected to a backup ThunderBay IV with the 4 disks configured as RAID-5 using SoftRAID. The Server TimeMachine function allows for setting the maximum disk space for each client so that a "overactive" user won't consume all of the available remaining disk space. If you can manage with each client receiving the same amount of allocated disk space, it seems to be working fine for me to back up all of the household computers.
  8. edanuff thread starter macrumors 6502

    Oct 30, 2008
    Ok, so sounds pretty much have to go with the RAID configuration. I'm not a big fan of software RAIDs but will give it a shot.
  9. belvdr macrumors 603

    Aug 15, 2005
    I have used SoftRAID in the past with success. If you're fearful of drive failure, then opt for RAID 6.

    One thing you might consider is using something like Logical Volume Manager (LVM) to create the volumes for the Macs, if you want them separate. In the Linux world, this gives us the ability to expand them easily, even with the underlying storage being a software RAID.
  10. hfg macrumors 68040


    Dec 1, 2006
    Cedar Rapids, IA. USA
    SoftRAID has been working fine for me here for quite some time now ... no problems. One advantage of a software RAID is that your data isn't tied to a specific enclosure chipset. If my enclosure (Thunderbay IV) should die, I can simply move the disks to any other JBOD enclosure and keep running ... I can even put the disks in my cMacPro tower if desired and they will continue to run just fine.
  11. edanuff thread starter macrumors 6502

    Oct 30, 2008
    I assume you mean RAID 5? I don't think SoftRAID supports RAID 6.
  12. IHelpId10t5 macrumors 6502

    Nov 28, 2014
    RAID is a pain just for backups. Instead, consider a thunderbolt or USB drive dock (StarTech has several) to attach to the Mini. Then, purchase two 3.5" HDDs that are at least twice the size of all the data that you wish to back up using Time Machine. Two 6TB HDDs would be reasonably priced at this point in time and could be physically rotated every few weeks for local redundancy. Mac OS Server can backup all of your Macs to a single Time Machine backup volume so there is no need to partition. Lastly, consider signing up for some type of cloud backup service such as Backblaze for an offsite backup solution. Local, real-time backup is certainly essential, but so is a way to get your backups off-site in case of catastrophic local disaster. This can come as as horribly as a house fire, or as common as a simple power surge or lightning strike that takes out your computers as well as all attached storage and backups.
  13. hobowankenobi macrumors 6502a

    Aug 27, 2015
    on the land line mr. smith.

    I have been running SoftRAID in RAID 5 mode off a mini (running Server 10.11) for about a year, with zero problems.

    I would suggest the RAID for your TM backups for the redundancy to protect against HD failure, but mainly so you can have a single volume of a larger size. TM is very space hungry (without any compression as many backup options have), so the more space the better. Having a single large volume allows much more flexibility in tweaking space allocations. Saves tons of headaches down the road.
    --- Post Merged, Dec 13, 2016 ---

    Yep, TM server is worth the cost of Server. Pretty slick. Probably one of the least known features.
  14. belvdr macrumors 603

    Aug 15, 2005
    I meant RAID 6, but you're right that SoftRAID doesn't support it. For me, larger volumes and redundancy is more important, so I'd look at RAID 10 or 5.
  15. AlanShutko macrumors 6502a

    Jun 2, 2008
    There is one specific reason I'd consider using multiple destinations rather than RAID. Time Machine over the network uses sparse bundles to store the backups, and those sparse bundles can develop filesystem corruption. Periodically Time Machine checks them and will attempt to repair any corruption, but often it can't and will tell you to start a new backup.

    If you have multiple destinations, odds are you will have one that is not corrupt, and you will be able to keep the backup history. Otherwise, you will probably lose the history.

    For me, it's not a big deal that I be able to go back in time very often, but if you do that a lot, you might consider using separate destinations.
  16. theluggage macrumors 68040

    Jul 29, 2011
    I wouldn't use RAID on backup drives - especially if "several Macs" is just 2 or 3.

    RAID is all about increasing speed - especially in multi-user/multi-tasking situations. The error parity checking in Raid 5 sounds reassuring is mainly there to compensate for the added risk of disk errors & corruption that comes from scattering data across multiple discs - and at the expense of making you buy more discs for the same space. There's also a fallacy that some people fall into when considering RAID's ability to survive a disc failure: several identical disks, bought at the same time (maybe made in the same batch) kept in exactly the same conditions in the same physical device have a raised probability of failing at the same time.

    Since Time Machine chugs away in the background it isn't that speed-critical.

    If you're serious about back-up, consider multiple time-machine backups per Mac (on different devices) or time machine plus some other form of backup (carbon copy cloner/superduper or a cloud-based backup).
  17. Cordorb macrumors regular

    May 8, 2010
    For me , using a RAID box for TM backups is more about being able to swap out a bad disk with no down time.

    AND the RAID box is auto backed up to an external USB disk which should be rotated and placed off site.

    as theluggage said speed is not the prime reason for all RAIDS

    Just a note : you can split RAID vols if your RAID box has 2 USB ports and use smaller external USB drives

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