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What Will Be the ill Effect, if there is, if my internal SSD is 2TB but the Time Machine External Backup is only 3TB, Merged by JBOD (1TB + 2TB SSD)?
- Thread starter Alvin777
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It will fill up sooner. No other bad effects. I think TM setup warns if you try to use a drive smaller than the internal. Depending how much of the 2TB is currently used and your data churn rate, the 3TB may work fine for quite a long time.
Not sure about JBOD. In theory shouldn't matter but that aspect is not ideal. I might just use the 2TB on its own as an interim while you save up.
Not sure about JBOD. In theory shouldn't matter but that aspect is not ideal. I might just use the 2TB on its own as an interim while you save up.
Fishrrman
macrumors Nehalem
I sense that the "JBOD" angle is going to cause you problems in the future...
Seriously. The 4 TB Samsung T5 EVO SSD I got just over a year ago is now 2x the price I paid. 😳
I was hoping to weed out the last HDDs out of my archive and backup setup, but that's now fully back-burnered.
The big SSD mentioned above is for my offsite backup, but my daily at-home Time Machine backup is still on an HDD. It's slow, but it still works.
Agree. You might find Carbon Copy Cloner gives you a bit more of a peek "under the hood" and will give you more guidance and troubleshooting in case anything goes wrong with your improvised drive setup.
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I've come across the paid apps Carbon Copy Cloner and SuperDuper! Does Carbon CopybCloner need the backup to be twice the capacity of the internal SSD?
true anythung that uses chips, they are up, RAM is 4 to 5x more expensive now as well, sadly
Can definitely vouch for CCC, been using it for years. It’s got a very very solid reputation. From what I understand Super Duper does as well, but I haven’t used it in a very long time myself.
No, the destination drive doesn’t need to be 2x the size but you will find older backups will get purged faster to make room for newer ones. Could be that CCC will pester you about wanting a bigger drive when you set up, but AFAIK it will still do it.
I would also say to look carefully at what exactly you need to back up. Maybe you can exclude some really big things that change a lot and that can be easily replaced (say, applications you can re-download from the App Store for example) if you want to save room so you have more versions of other files.
Fishrrman
macrumors Nehalem
"Does Carbon CopybCloner need the backup to be twice the capacity of the internal SSD?"
No.
So long as you maintain a standard "clone" (where the cloned backup contains the same items as the source), it won't grow in size (unless your source volume grows, also).
CCC also has a "safety net" feature which retains old copies of changed files. In this way, it somewhat mimics time machine. BUT... if you use the safety net, the backup will slowly grow in size, as well.
No.
So long as you maintain a standard "clone" (where the cloned backup contains the same items as the source), it won't grow in size (unless your source volume grows, also).
CCC also has a "safety net" feature which retains old copies of changed files. In this way, it somewhat mimics time machine. BUT... if you use the safety net, the backup will slowly grow in size, as well.
Out of the box, CCC doesn't do the “safety net” folder the way it used to. Now it just takes snapshots of your drive. Each one looks like a full backup, but it’s smart enough to make copies only of files that have changes.
I think in most backup situations you do want file versions saved, versus just a strict 1:1 copy of your drive, to account for files that accidentally deleted or corrupted or just saved in error. CCC handles this well, but it does need space to do it. You can claw back some space by not backing up stuff that you can readily replace.
OP, if price/capacity is a concern I would also consider doing a full backup as well to a basic hard drive. It will take ages, but it will save your data, and then you could keep your SSD-based backup focused on stuff that changes more frequently.
Personally I would buy cheap HDD for backup before kludging a JBOD setup for TM backup. Adding JBOD complexity for no value add (speed being irrelevant for most folks' backup) makes no sense.
Howard2k
macrumors 604
Yeah that's the biggest alarm bell for me.
Total capacity is just going to limit how far back in time you can go.
I used CCC for disaster recovery for my old Intel Mac but CCC wants more $ for the SoC version, so am seriously thinking of switching to Super Duper which is freeware. Another thing I dislike CCC was no compression, not very cost effective for backup. If your data backup is comprised mostly video files and mp3, which are already compressed, this would be a no-issue.
This. My TM drives are all HDDs for this very reason.
And back to OP, ideally, Apple has recommended in the past 2.5x bigger drive for TM, however...
@Mike Boreham post is spot on. Add in: OS is no longer backed up as that's a sealed volume. Initial copies of, say, photos library might cause a big hit but as Mike pointed out, might be relatively static (no churn), so will only be getting deltas (read: adding new images but not doing anything with pictures from 5+ years ago).
So if only using say half the internal and external is 2x size, probably good to go for a fair amount of time.
