Time Machine 2tb limit?

[sphardy]

Check out: http://www.readynas.com/?p=253

I have 3 mac's all running this way with custom-sized sparsebundles and custom permissions. Not over 2 or 4TB, but I have read of at least one user successfully doing just that by this same method.

Note: If you're using Snow Leopard, take care regarding the sparsebundle naming convention as it appears to have changed (no ethernet address in the name)

[mdgm]

I've already asked about the 4TB limit.

See 4.2.10 T40 some questions

I'm just curious as to why NetGear would set a 4TB limitation for Time Machine (I'm not going to hit that anytime soon so it doesn't really bother me that much).

The Time Machine limitation get resolved slightly with Ext4, but the way we handle Time Machine so that it doesn't overrun the capacity on your ReadyNAS (which it can easily if you don't put a limit) requires more changes to support more than 4TB.

Perhaps NetGear or a community add-on developer like super-poussin could develop an add-on to allow users primarily using their ReadyNas for Time Machine to set a higher limit?

[centauratlas]

Thanks. I can get it running fine as long as the backup is going to be less than 4TB (now, 2TB before). It is just that Frontview and the ReadyNAS limit the size for some reason.

Thanks for the tip on the naming, fortuitously I had used: MacPro-DQC.sparsebundle so I don't think that is the issue. I can create the sparsebundle on the Mac, even copy the 6TB sparse image over to the ReadyNAS, but can't get Time Machine to recognize it.

Using the Frontview method, it has no problem backup up as long as it is under 4TB.

Strange.

Check out: http://www.readynas.com/?p=253

I have 3 mac's all running this way with custom-sized sparsebundles and custom permissions. Not over 2 or 4TB, but I have read of at least one user successfully doing just that by this same method.

Note: If you're using Snow Leopard, take care regarding the sparsebundle naming convention as it appears to have changed (no ethernet address in the name)

[sphardy]

@centauratlas

It may just be a naming issue still. One way to double check is to point TM to a standard share on your nas without any pre-prepared sparsebundle and then start a backup job. This may fail but IIRC TM does *try* to make the sparsebundle and you will see this and the name that is used.

As a test I pointed one of my machines (10.6.2) to a new share and kicked off a TM backup. In the past this would fail as TM cannot make the sparsebundle, but interestingly under the 4.1.7 beta firmware the sparsebundle was created just fine. (note I'm using an NV+, not a pro)

I stopped the backup and, instead of creating a sparsebundle, used terminal & resized the TM created sparsebundle to 4TB

Code: Select all

hdiutil resize -size 4T <sparsebundle>

I verified the size by mounting it before kicking off a backup job which then seemed to work fine, though I can't properly test this as I don't have an easy way to generate the backup data needed, nor the time.

But in principle it looks like it is possible to manually create a sparsebundle larger than the current Frontview limits

[mdgm]

As a test I pointed one of my machines (10.6.2) to a new share and kicked off a TM backup. In the past this would fail as TM cannot make the sparsebundle, but interestingly under the 4.1.7 beta firmware the sparsebundle was created just fine. (note I'm using an NV+, not a pro)

TM can make the sparsebundle fine under Leopard on 4.1.6. RAIDiator 4.1.7 for Sparc and RAIDiator 4.2.10 for x86 include Netatalk 2.0.5. This includes Snow Leopard Time Machine Support along with a range of other AFP fixes.

[centauratlas]

Hi,
Thanks for the reply. I am going to give it a try and see.

The thing is that I can use whatever bundle it is named, if it is ~4TB or below.


Thanks

@centauratlas

It may just be a naming issue still. One way to double check is to point TM to a standard share on your nas without any pre-prepared sparsebundle and then start a backup job. This may fail but IIRC TM does *try* to make the sparsebundle and you will see this and the name that is used.

As a test I pointed one of my machines (10.6.2) to a new share and kicked off a TM backup. In the past this would fail as TM cannot make the sparsebundle, but interestingly under the 4.1.7 beta firmware the sparsebundle was created just fine. (note I'm using an NV+, not a pro)

I stopped the backup and, instead of creating a sparsebundle, used terminal & resized the TM created sparsebundle to 4TB

Code: Select all

hdiutil resize -size 4T <sparsebundle>

I verified the size by mounting it before kicking off a backup job which then seemed to work fine, though I can't properly test this as I don't have an easy way to generate the backup data needed, nor the time.

But in principle it looks like it is possible to manually create a sparsebundle larger than the current Frontview limits

[Francofinch]

Hello!! I am looking at buying a few of the 2TB Time Capsules for our office, where we have about 20 unibody MacBook Pros with 128GB SSDs.

Is there a limit on the number of Macs that a single 2TB Time Capsule can provide Time Machine backup targets to? Does anyone have advice or experience regarding using a Time Capsule as a target for multiple machines?

[nathan-opscode]

http://www.readynas.com/forum/viewtopic.php?f=71&t=57003

No single TM over the limit, but this method is allowing me to make use of the space divided out amongst a number of users.

[mdgm]

The 4TB limit for x86 ReadyNAS has been lifted (this thread is quite old by the way). The 2TB limit still applies to Sparc (I think).

Francofinch, personally I wouldn't use a Time Capsule. A ReadyNAS Pro 6 (RNDP6000-200) would be a great choice.

[Snuffyspaw@aol.com]

I want to be sure I understand this limit stuff. Please correct me where I'm wrong.

TimeMachine has a 2 TB limit for its sparsebundles. ReadyNAS with a sparc board has a 2 TB limit for each hard drive. ReadyNAS with a x86 has no limit for each hard drive?

[mdgm]

The limit is based on the filesystem. Sparc ReadyNAS use EXT3 which has a 2TB limit per file. native EXT4 with huge file support (on x86 ReadyNAS last factory reset on 4.2.11 or later, 4.2.12 or later for NVX or 2100v1) has a 16TB limit per file.

As for the drive size limit, that is an unrelated issue. Sparc ReadyNAS (e.g. Duo v1 and NV+ v1) do not have GPT support which means they can't handle drives larger than 2TB in size. x86 ReadyNAS on 4.2.16 or later have GPT support. While there is a limit on what can be handled on x86 ReadyNAS at this time it's huge and we're several years away from reaching that limit.

The Duo v2 and NV+ v2 are ARM devices and can handle drives larger than 2TB in size. On ARM devices you set a quota for Time Machine larger than 2TB

[Snuffyspaw@aol.com]

Thanks for your prompt response.

The board in the ReadyNAS unit has a file size limitation and an unrelated hard drive size limitation.

How does the TimeMachine limitation fit into this? Is it the same as the file size limitation of the board? Or is it a third separate issue?