Common Problems with Time Machine and the ReadyNAS

One of the great features of the ReadyNAS line which helps set it apart from its competition its excellent Mac support. All ReadyNAS support AFP (Apple Filing Protocol) and Time Machine. The ReadyNAS uses heavily customised Debian Linux optimised both for the ReadyNAS hardware and NAS use. NetGear is a customer of NetAFP (the company which develops the Netatalk project which provides AFP and Time Machine support to Linux devices).

As of 4.1.8+ (Sparc) and 4.2.18+ (x86) there is now support for Mac OS X 10.7 Lion on all ReadyNAS units.

Following NetGear’s guide, setting up Time Machine on the ReadyNAS is easy. However some of the information mentioned there is out of date (the 2TB limit no longer applies to x86 ReadyNAS which now support Time Machine quotas >4TB if running RAIDiator x86 4.2.16 or later; also the sparsebundle images can be expanded subject to the condition specified in problem #2 below). There are a few problems you may encounter which you should be aware of:

1. Have free space but cannot increase Time Machine quota

This is best explained using an example: Let’s say you have 2x1TB disks using RAID-1 or X-RAID/X-RAID2. Let’s say you have 500GB allocated to Time machine and have you used 450GB on Time Machine and 200GB for other data. You want to increase the Time Machine limit to 600GB. However as you have less than 600GB of free space on your volume you cannot change the quota to 600GB under Backup > Time Machine. There are multiple solutions:

i.) Disable Time Machine on your Macs, delete Time Machine backups, increase TM quota, then re-enable Time Machine and do fresh TM backups. PROBLEM: You lose your backup history. Not very satisfactory

ii.) Disable Time Machine on your Macs, you backup your Time Machine backups (e.g. to a USB disk or another NAS), delete them, increase the TM quota, then copy your TM backups back onto the NAS and re-enable Time Machine on your Macs. PROBLEM: Very time consuming

iii.) If you are comfortable with the command line you can SSH in and fix the problem. PROBLEM: This does require SSH access and you do need to know what you are doing.

a.) First disable Time Machine on your Macs (we don’t want any Mac to backup to the NAS while we are doing this process).

b.) Check how much space you have free on your volume and ensure that the amount you intend to allocate to Time Machine is less than current space used by Time Machine + free space on your volume. You may find my TimeMachineLog add-on useful for this.

c.) Login to the NAS via SSH (help can be provided on the ReadyNAS Forums on how to do this if you don’t know how).

d.) Decide how much space you wish to allocate to Time Machine. In this case let’s say 600GB and set the quota.

To change the quota e.g. to 600GB (629145600KB) type

MDGM-NAS:~# setquota -u ReadyNAS 629145600 629145600 0 0 /dev/c/c

e.) Check to make sure you did your maths correctly (note that the command below requires quotes as shown on x86 and no quotes on Sparc)

MDGM-NAS:~# repquota -as | grep "limits\|User\|ReadyNAS"

f.) Re-enable Time Machine on your Macs

iv.) You could expand an X-RAID/X-RAID2 volume by adding extra disks (if empty drive bays) or replacing existing disks to expand your volume. PROBLEM: This costs money and you may not wish to do this if you still have plenty of free space.

2. Expanded the quota allocated to Time Machine but backups are still limited to what they were before.

Please note that if backing up from a Mac OS X 10.5 Leopard machine the space allocated to the backups cannot be expanded. You could possibly copy the backup sparsebundle to your Mac, expand the sparsebundle, then copy it back to the NAS, but this is quite time consuming.

On Mac OS X Snow Leopard, I believe this limitation has been lifted in one of the Mac OS X Snow Leopard point releases. Consequently it’s recommended you run the latest version of Mac OS X 10.6 Snow Leopard unless you cannot do so (e.g. if you have a PowerPC Mac).

3. Backing up to ordinary ReadyNAS shares, not following “Easy Time Machine Setup with the ReadyNAS” and backups fail after upgrading to Mac OS X 10.7 Lion

This issue will probably require a separate article. For now please see A Note Regarding Time Machine Support and Mac OS X Lion

Category: Uncategorized 4 comments »

4 Responses to “Common Problems with Time Machine and the ReadyNAS”

  1. Mike

    Thanks for your comments regarding the ReadyNAS system and Time Machine. I am running Mountain Lion 10.8.2 on a MacBookPro 4,1 model with 2.4GHz Core 2 Duo machine. The ReadyNAS is an Ultra 4 running X-RAID2 RAIDiator 4.2.22 (which I just updated from 4.2.21), with 4-disks using only 7% of a total of 906GB used. My ReadyNAS Time Machine backup is set to 200GB for a 200GB internal Mac hard drive that is currently using 170GB. The issue happened when the ReadyNAS was running RAIDiator 4.2.21. I do have a feeling that the Time Machine setup size is too low, and it should be set a bit higher for this to operate properly.

    It does normally work, but there have been two (2) times when the Mac system will state that the Time Machine backup “verification” is invalid, and the entire backup must be redone from scratch. Of course, this is very time consuming over a network, and you do lose the backup history. Any comments as to what might be causing this type of error? Thanks in advance.

  2. mdgm

    Take a look at http://www.garth.org/archives/2011,08,27,169,fix-time-machine-sparsebundle-nas-based-backup-errors.html

  3. Mike

    Thanks for the quick reply. I will reference that information the next time I receive the same verification error.

  4. Brook

    I have also had the error stated by Mike, I will check on what article, but I’ll just add that I was also getting that error when I was using a 2tb drive attached to an Airport Extreme with two macs backing up to it. The odd thing i’s mainly one of the computers that does this and it doesn’t appear to be related to the amount of disk used on these macs.

    My main reason for commenting is as follows: I frequently wake the computer up to find a message saying it failed. I thought it’s because the NAS has gone to sleep. But it will still do it if I leave the mac copying files to or from it while I sleep. Happens quite often to both macs. I use a utility called “TimeMachineEditor” to set the mac to backup less frequently and I didn’t want the NAS being constantly awake between two macs backing up every hour. This is not just for power usage but also to allow it to rest, not running the disks so hard. I’m using a ReadyNAS NV+ (spark) 4x2tb drives.

    Additionally I recently setup the slightly newer version (NV+ v2) for a friend, uses the nice looking FrontView. I was not able to get TimeMachine to work on that machine at all. I’m going to have another crack at it when I visit next. I’m pretty sure I had set it up correctly but for some reason TimeMachine control panel refuses to see the NAS as it does with mine and as instructions indicate. Any thoughts on that.

    Thanks for your time. Cheers, Brook


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