Backup Strategies?

[gastropod]

Not so sure I need to double my backup

But what you do have you’d hate to lose, instead of merely your employer hating to lose it.

Redundancy in all things is a good policy. You can’t really cover all things, but at a minimum the number of backups, types of media, location, and backup software have all proven to be important over the years.

You need more than a single backup drive. Backup drives fail, and they can fail at the same time as the original drive e.g. if there’s a bug in the OS. With two backup drives, rotate them so that one is always disconnected.

Media types have different failure modes. SSDs are far better than they used to be, but when they do fail, they often fail with no warning whatever. HDs usually show signs of trouble such as slowing down from multiple retries at reading and writing soon enough to replace it while the data is still accessible. Having one SSD for a potentially fast restore, and an HD for more potential to rescue the data on the backup disk is a good plan. A failing HD is also useful as an archival copy.

You need at least two separated locations. House fires, thieves, and earthquakes happen. Keeping a backup copy at a friends house will help with the house fire or thieves, but possibly not for earthquakes or tornados. Online off-site backups the best solution for a regional disaster, but check where the servers are physically located–you don’t want them to be in the same regional disaster that could hit you.

All software has bugs, including backup software. Back in the day (late 90s?), LaCie made their Silverfast backup software free for the basic features. I tested it see if I should recommend it to users, only to find out that on each run it would randomly not backup a folder tree or four. Other backup software, including Time Machine, have had problems. Use at least two different ones. My favorite example is still from a Tidbits server failure:

TidBITS Outage Causes Editors Outrage - TidBITS

A wonderful very short tutorial for backup strategy (in the form of a story) is the Tao of Backup. It describes the important issues for reliable backups and how things go wrong.

The Tao Of Backup

[mschmitt (Michael Schmitt)]

@gastropod

You need more than a single backup drive. Backup drives fail

I just had a 4TB HDD backup drive fail on Friday. Completely dead. No prior signs of trouble.

[Shamino (David C.)]

@tidbits41

Not so sure I need to double my backup, like I said, I no longer have live work at home, it’s just all my email & photos.

It all depends on what you can afford to lose. TM is very convenient, but given the cost of backup media, I think it’s worth using at least two different solutions on at least two different storage devices. It would be terrible if something (hardware or software) glitched, ruining your only backup.

@tidbits41

I HAD been thinking about a fast NVMe for backup… but that was before I learned no bootable backup. I had planned to spend about 250 bucks on that, but maybe I can rethink that. I could go with just a HDD (or two) or a external SSD, like the Samsung T7 for 150 (@ one third the read/write performance my previous plan had).

If you’re not going to actually boot from the backup, it will all come down to what you consider acceptable performance and what you want to spend.

I’ve been using HDDs because the time for a backup isn’t that bad. A few hours for the first initial backup and much less for subsequent incremental backups. About 5-10 minutes for a Time Machine hourly backup. About 30-40 mins for a CCC clone (usuallly run weekly or whenever I get around to it.)

An SSD will be faster, but I don’t need that much speed. Of course, a system restore will also go faster on an SSD, but I don’t expect that to happen very often, and I’m willing to take the necessary time when it does.

@tidbits41

I AM familiar with CCCs Safety Net which is hugely inconvenient to use compared to TM.

In what way? Safety Net, when the destination of HFS+, is a a pain in the neck - you get a Safety net directory that holds old versions of those files that were replaced. Which is awkward if you are trying to access the drive’s content for a particular date.

But when CCC’s destination is APFS, it uses snapshots, just like Time Machine. You don’t have a fancy GUI mechanism for walking through a file’s history, but you can mount the snapshot corresponding to any historic backup and browse its files. Just like you can with Time Machine.

@tidbits41

Oh, building from scratch! The 95 bucks item I mentioned is pre-built. So far I have been pleasantly surprised that Chinese no-name stuff seems to perform and work quite well.

I always build my external drives (HDD and SSD). You don’t necessarily save any money, but you get to pick your components and avoid el-cheapo stuff that may perform poorly or fail under heavy load.

For HDDs, I always look for 7200 RPM drives that are rated for 24x7 operation - which you don’t usually find in commercially-built USB drives. And I look for enclosures with fans, because high performance drives can easily overheat without them.

For SSDs, I always look for a brand I trust (e.g. Samsung or Crucial). I’ve read too many articles about no-name discount devices lying about capabilities. Maybe SATA instead of NVMe or USB instead of Thunderbolt, or reporting capacities many times higher than reality (resulting in data loss when you start to actually write files to the device). This is for internal or external, and again, I prefer to build my own so I know what’s inside the device.

@tidbits41

As it is, I’m going for the 1T internal in the Mini so I have no need for T4 external storage (which I believe is still a tad slower than the internal storage).

I recommend backup devices be 2-3x the size of the source media. Using snapshots, you can save many historic backups to the device. Even if you fill your Mac’s 1TB storage, you won’t be saving 1TB of data, unless you completely fill it, but the headroom lets you store lots of archival backups.

FWIW, my current Mac has 2TB of storage. A little more than 1TB is used. My 4TB backup devices are each about 50% full, and have backups that go back several years (since this computer first went into service). Had I chosen 2TB storage devices, they would have filled up by now, and I’d be deleting old snapshots to make room for new backups. I could’ve gotten 3TB devices, but the price for 4 was not much more.

Of course, had I chosen to back up to SSDs, the math would be a bit different, because drives larger than 2TB an quickly become prohibitively expensive.

[tidbits41 (paulc)]

Cool, as long as using the snapshot in CCC acts pretty much like TM I can go with CCC… yeah I gotta pay Mike (upgrade for under 40 bucks) but that’s cool, over the years there have been a few occasions where I had questions and he personally responded pretty quickly.

When I was working, my home setup was a production environment and multiple back-ups ruled the day. Now, it’s just my mail, photos & videos, music. When I go with the Mini, I will have several backups… my 2 SSDs boot volume of my cMP, a single drive clone of it PLUS I have all the music on a FATex drive because my Mac in iToonz will not access my phone, so I have to access it under winblowz to copy music to the phone! Chances are I will put at least the music on a thumb drive because I will need to copy it to whatever pc I eventually get… not to mention dealing with my phone unless I can far more easily deal with it in the latest macOS.

This whole process has got me looking at things I didnt pay all that much attention to, like thumb drives… holy smokes, I come from the 4G and 8G days and now… 20 dollar ones holding 128G. I could very cheaply create even another copy of my stuff.

[LarryR (Larry Rosenblum)]

A nice side benefit of Backblaze is that they have an iOS app for restore. If you are away from your Mac and need a file from it, you can download it to your iPhone or iPad. I’ve used this a few times while traveling.

[Simon]

Capacity is another issue worth considering. It’s usually my advice not to overspec capacity. Sure, you probably want several times the size of the files you’re backing up (say a 2TB TM drive for ~400 GB of files), but I caution against going much larger than that.

Two simple reasons: first, you rather have two drives, one of which is newer, instead of just one old device, especially with HDDs that have mechanics that are not known to age particularly well. It’s just added redundancy. Secondly, cost. Buying top capacity drives always comes at a premium. If you instead buy more middle of the road capacity you are always going get the best price/TB ratio. And the drive you buy a year or two from now, will always be the less expensive drive.

TM can easily choose to continue backing up to a new drive, SD and CCC will obviously back up to a new drive just the same as before. You store your previous drive safely so that you can access it should you truly need to get at very old data. But I would strongly urge against trying to go as big as possible in an attempt to back up all to one big drive only. It’s not worth the added cost and it unnecessarily puts you at additional risk.

Edit: And don’t forget not to fill up disks substantially beyond 80%. Both in terms of performance and reliability, you’d rather get a new drive a month early than fill to capacity an older drive.

[jeff1 (Jeff Hecht)]

@mschmitt

I just had a 4TB HDD backup drive fail on Friday. Completely dead. No prior signs of trouble.

Which reminds me that over the last few years I have had more failures on backup drives than on the working drive.

One other note – Time Machine can be very useful if adjustments you are trying to make go bad. It’s possible to go back a few days to whatever you were fiddling with and get the original settings back.

[Shamino (David C.)]

@jeff1

Time Machine can be very useful if adjustments you are trying to make go bad. It’s possible to go back a few days to whatever you were fiddling with and get the original settings back.

Not to mention being able to recover data from older files when you make a mistake.

Most of my uses of Time Machine have been after I accidentally make a typo in a Word or Excel file and accidentally save my change. With Time Machine, I never lose more than an hour’s worth of work when this happens. I can restore an older version and then manually copy/paste the changes I want to keep from the current version and discard the mistakes.

This is especially important for the spreadsheets I use for my personal finances, which I usually update once a day. If I discover an error, I have the daily revision history for the last two weeks, with which I can always locate the cause of the error, allowing me to confidently fix the error.

[Kierkavon]

I used to use CCC, surprised that nobody has mentioned SuperDuper. I have used it for bootable clones the last 8 years and found it to be faster, easier, bulletproof. And it deals with the System/Data Volume aspect automatically. It’s never let me down.

[neil1 (Neil Laubenthal)]

Nothing wrong with SD if you only want to clone an entire drive…but CCC makes it much simpler to backup folders with various retention options…that’s possible but inscrutable with SD, and the author is completely uninterested in making folder backups easy to setup. Amd it won’t reliable do the locked system volume either IIRC.

[glenthompson]

Years ago I tried both SuperDuper and CCC and decided I liked CCC better. Haven’t revisited that decision because CCC dies what I need.

[raykloss (Ray)]

So I was just doing my weekly Time Machine backup (besides my regular TM, I have a 18TB disk for weekly TM backups), and decided to check the drive with DU. The backup seemed to go OK, and the device and the Volume check out OK (with 37 Snapshots), but the container check is telling me [error: container /dev/rdisk12 is mounted. / Storage system check exit code is 65. / Storage system verify or repair failed. : (-69716)]. Is there a way to save the TM backups and do I need to reformat the drive all over? Can I copy the TM Snapshots via the finder, reformat, and then copy them back?