Promise Pegasus – backup options?

[jimthing]

I have a question about backups, I'm really stuck trying to get a handle on...

Having researched a lot for storage devices for HTPC content and other file storage, I have decided to bite the Thunderbolt bullet, and go for this set-up, to go with a 2012 Mac Mini, as a type of central server for all my files:

- 2x Promise Pegasus R6's (got a great deal on them secondhand!).
- using 1x R6 (main storage), 1x R6 (backup copy of main storage) – as all raids can fail!
- replacing drives in both R6's for fast 7200rpm 4TB Hitachi Deskstar 7K4000 – affordable, and enough for nxt 3yrs storage needs!
- both in RAID 5 level: 6x 4TB = 20TB available on each R6 (1x 4TB drive used for redundancy).
- using 2x 3metre StarTech cables, so I can store the R6's away in a cupboard to de-noise my environment (as they are just a bit too noisy).

The Mac Mini is essentially just the boot machine (has a 256GB SSD, and the OEM Apple 1TB 5400rpm HDD in it – not Fusion Drive'd together!), and perhaps anything I need fast access to.


Anyway, the main question I am still wondering about though:
What is the best way of handling backup, for both the R6 holding all my data, and the SSD in the Mini?

An idea is:
(1) use Time Machine to save the 256GB SSD to the OEM Apple 1TB HDD (also saving a 256GB partition for a "clone" of the SSD, in case I need to boot from it, which you can't do with Time Machine AFAIUI).
(2) also use Time Machine to back-up the first R6 to the second R6.

Is this even possible for TM to do?

If I use Time Machine to backup the main storage R6 to the backup R6, and the main storage R6 fails completely (e.g. if 2 drives failed in the main R6, braking the RAID 5 completely, and I replaced them to start afresh), can one rebuild the main storage R6 using the backup R6's Time Machine backup?

Anyone know if Time Machine would be able to do this? Or instead is there a better way to do backups from one external drive to another external drive? Cloning will copy faults over identically, so not something I'd really want to do, I think.

Any advice gratefully received from the smart tech peeps I know hang around here on MacRumors!

(PS. add-on question: any idea on whether I should use a "data scrubber", and if so which?)

 

[hfg]

If you put both of the Pegasus drives in your Time Machine drive list, the TM backup will alternate between them each hour. This is better than backing up one from the other to avoid propagating a possible corrupt file from the first backup device over to the second backup device. Both backup devices receive first-generation data from the original source every time.

 

[jimthing]

If you put both of the Pegasus drives in your Time Machine drive list, the TM backup will alternate between them each hour. This is better than backing up one from the other to avoid propagating a possible corrupt file from the first backup device over to the second backup device. Both backup devices receive first-generation data from the original source every time.

I don't think you read my post correctly. I am planning on using one R6 as my main storage device (all my files on it), with the the second R6 being a backup of the first R6:

R6#1 (file storage) ==> R6#2 (backup of R6#1)

What is the best solution for backing-up from one to the other? (or any other backup set-up suggestions, anyone can offer to me?).

Thanks in advance.

 

[marzer]

I have a question about backups, I'm really stuck trying to get a handle on...

Having researched a lot for storage devices for HTPC content and other file storage, I have decided to bite the Thunderbolt bullet, and go for this set-up, to go with a 2012 Mac Mini, as a type of central server for all my files:

- 2x Promise Pegasus R6's (got a great deal on them secondhand!).
- using 1x R6 (main storage), 1x R6 (backup copy of main storage) – as all raids can fail!
- replacing drives in both R6's for fast 7200rpm 4TB Hitachi Deskstar 7K4000 – affordable, and enough for nxt 3yrs storage needs!
- both in RAID 5 level: 6x 4TB = 20TB available on each R6 (1x 4TB drive used for redundancy).
- using 2x 3metre StarTech cables, so I can store the R6's away in a cupboard to de-noise my environment (as they are just a bit too noisy).

The Mac Mini is essentially just the boot machine (has a 256GB SSD, and the OEM Apple 1TB 5400rpm HDD in it – not Fusion Drive'd together!), and perhaps anything I need fast access to.


Anyway, the main question I am still wondering about though:
What is the best way of handling backup, for both the R6 holding all my data, and the SSD in the Mini?

An idea is:
(1) use Time Machine to save the 256GB SSD to the OEM Apple 1TB HDD (also saving a 256GB partition for a "clone" of the SSD, in case I need to boot from it, which you can't do with Time Machine AFAIUI).
(2) also use Time Machine to back-up the first R6 to the second R6.

Is this even possible for TM to do?

If I use Time Machine to backup the main storage R6 to the backup R6, and the main storage R6 fails completely (e.g. if 2 drives failed in the main R6, braking the RAID 5 completely, and I replaced them to start afresh), can one rebuild the main storage R6 using the backup R6's Time Machine backup?

Anyone know if Time Machine would be able to do this? Or instead is there a better way to do backups from one external drive to another external drive? Cloning will copy faults over identically, so not something I'd really want to do, I think.

Any advice gratefully received from the smart tech peeps I know hang around here on MacRumors!

(PS. add-on question: any idea on whether I should use a "data scrubber", and if so which?)

Yes, Time Machine is an excellent choice for what you want to do.

Its what I do with a similar config. I have 2x6TB LaCie 2big Thunderbolt enclosures connected to a Mac mini as server. The first is in RAID 1, providing 3TB of mirrored primary storage for the home media library. The second is in RAID 0, providing 6TB of high-speed backup storage. I use Time Machine as my backup system. With the additional space on the RAID 1 backup drive, three other computers in the house also backup via Time Machine over the network...Oh, and the Mac mini also backs up to the 6TB drive via Time Machine.

 

[flynz4]

I have an 8TB Pegasus R4 (configured as 4TB RAID 10).... but I have nowhere near as much data as you. Plus, all of my data is for personal use only. It is not part of any business.

Between my 768GB SSD, and my R4... I have about 1.5TB of total data that I care to back up. I am using Time Machine to a 3TB Time Capsule, plus it is all backed up to Crashplan+. Between the two, I have both local and offsite backup with deep versioning... allowing me to roll back to recover any data corruption.

In addition, I have ripped my DVD collection, but I do not back that up to either TM or CP+... it just isn't that valuable to me. All of those movies are "replaceable data". I do have that stored on two different locations inside the house (Pegasus R4 + a NAS). I figure it is only a matter of time before I will never want that media again anyway... as I suspect that movie content will just become a "service" (ex: as Netflix and its competitors just provide "all the video in the world" on demand). At that point... it is pointless for me to even keep commercial videos any longer. I have pretty much stopped buying any new DVD movies in anticipation of this.

Regarding the Pegasus R4... as stated, I back it up to TM & CP+. I also run a nightly CCC clone of all of my personally created media (from both my SSD + R4). This includes my Aperture library, my FCPX projects, and my home camcorder originals. I back these up to an inexpensive Thunderbolt attached Seagate 3TB drive. Note that I do NOT consider this clone to be a "true backup". That is because clones do not contain viable "history"... so any programatic or human errors (especially those that are undetected) just propagate. My motive for this clone is to be able to move my media to any other computer in the event of a crash (either a drive, or the system). I like the Seagate drives because I can use either TB, FW, USB 3, or even USB 2 interfaces depending on which computer I needed to use.

For you (with 20TB of data) you really have no choice but to use the second R6 as a backup destination. Assuming this is all valuable data... especially if this is otherwise irreplaceable data, then you need an offsite storage plan as well. Using the internet is probably not feasible for this much data. Also... singe spindle drives (such as my 3TB drives) are not viable either. You may want to invest in a commercial backup system (either HDD or tape) if this data is critical to a business. Both would be extremely expensive... but with 20TB of data... then you really have no choice.

Regarding the backup method for moving the data to the second R6... you have a couple of choices. You can clone the data... but then you really do not have "backup"... you only have a "copy". Any errors in the data will replicate... and history will be lost. If this is irreplaceable data... you have a huge hole in your strategy. A better approach would be to use a true backup program (like Time Machine)... to backup your entire system (including the primary R6) to the backup R6. This would give you a true backup (albeit only one). It also does not allow you to keep working if your primary R6 was to fail. You would need a 3rd R6 if you wanted both a clone & a backup. Personally, I think a backup is more important (to me)... because I think it is critical to recover from data errors. As stated... I do use both... but my clone fits on a cheap single spindle Thunderbolt drive.

/Jim

----------

- using 2x 3metre StarTech cables, so I can store the R6's away in a cupboard to de-noise my environment (as they are just a bit too noisy).

You can use a single cable to get to your cupboard... and then daisy chain to the second using a 0.5m cable.

/Jim

 

[jimthing]

Yes, Time Machine is an excellent choice for what you want to do.

Its what I do with a similar config. I have 2x6TB LaCie 2big Thunderbolt enclosures connected to a Mac mini as server. The first is in RAID 1, providing 3TB of mirrored primary storage for the home media library. The second is in RAID 0, providing 6TB of high-speed backup storage. I use Time Machine as my backup system. With the additional space on the RAID 1 backup drive, three other computers in the house also backup via Time Machine over the network...Oh, and the Mac mini also backs up to the 6TB drive via Time Machine.

Time Machine won't do this, as seemingly it won't backup from EXTERNAL to EXTERNAL. If I have it right, TM will only backup the Mac boot drive AND an external (or more than one external) to another backup external (or more than one backup external, if one wants to have rotating backups).

I have an 8TB Pegasus R4 (configured as 4TB RAID 10).... but I have nowhere near as much data as you. Plus, all of my data is for personal use only. It is not part of any business.

Between my 768GB SSD, and my R4... I have about 1.5TB of total data that I care to back up. I am using Time Machine to a 3TB Time Capsule, plus it is all backed up to Crashplan+. Between the two, I have both local and offsite backup with deep versioning... allowing me to roll back to recover any data corruption.

In addition, I have ripped my DVD collection, but I do not back that up to either TM or CP+... it just isn't that valuable to me. All of those movies are "replaceable data". I do have that stored on two different locations inside the house (Pegasus R4 + a NAS). I figure it is only a matter of time before I will never want that media again anyway... as I suspect that movie content will just become a "service" (ex: as Netflix and its competitors just provide "all the video in the world" on demand). At that point... it is pointless for me to even keep commercial videos any longer. I have pretty much stopped buying any new DVD movies in anticipation of this.

Regarding the Pegasus R4... as stated, I back it up to TM & CP+. I also run a nightly CCC clone of all of my personally created media (from both my SSD + R4). This includes my Aperture library, my FCPX projects, and my home camcorder originals. I back these up to an inexpensive Thunderbolt attached Seagate 3TB drive. Note that I do NOT consider this clone to be a "true backup". That is because clones do not contain viable "history"... so any programatic or human errors (especially those that are undetected) just propagate. My motive for this clone is to be able to move my media to any other computer in the event of a crash (either a drive, or the system). I like the Seagate drives because I can use either TB, FW, USB 3, or even USB 2 interfaces depending on which computer I needed to use.

For you (with 20TB of data) you really have no choice but to use the second R6 as a backup destination. Assuming this is all valuable data... especially if this is otherwise irreplaceable data, then you need an offsite storage plan as well. Using the internet is probably not feasible for this much data. Also... singe spindle drives (such as my 3TB drives) are not viable either. You may want to invest in a commercial backup system (either HDD or tape) if this data is critical to a business. Both would be extremely expensive... but with 20TB of data... then you really have no choice.

Regarding the backup method for moving the data to the second R6... you have a couple of choices. You can clone the data... but then you really do not have "backup"... you only have a "copy". Any errors in the data will replicate... and history will be lost. If this is irreplaceable data... you have a huge hole in your strategy. A better approach would be to use a true backup program (like Time Machine)... to backup your entire system (including the primary R6) to the backup R6. This would give you a true backup (albeit only one). It also does not allow you to keep working if your primary R6 was to fail. You would need a 3rd R6 if you wanted both a clone & a backup. Personally, I think a backup is more important (to me)... because I think it is critical to recover from data errors. As stated... I do use both... but my clone fits on a cheap single spindle Thunderbolt drive.

/Jim

----------

/Jim

This is not for business, it's home use (video takes lots of space). I bought this space to grow into, i.e. I currently have only ~6TB of data, but worked-out I'll probably need another ~6TB more this year, and then annual growth of ~3TB per year after that. So 6+6 (+3+3, for another 2 years) = 18TB, plus a couple of TB extra in case of overrun for those three years (or perhaps I may get an extra fourth year, if lucky).

This was why I was going to do incremental backups. From reading about Carbon Copy Cloner (CCC) and Super Duper (SD) they both seem to do incremental CLONE backups only; a sort of half-way house solution. As this means it does a mass clone at the beginning, then checks files for changes on the main storage external, and CLONES any new files or changed files to the backup external.

This does not sound the same as Time Machine —which as I said above, won't work anyway, because it looks like it won't do external to external— which if it could, would be better as it would offer file VERSION history, thus any propagated errors could still be recovered from for a period afterwards (until it had to wipe the oldest to make space for newest – 'deltas' I think they are called).
Apparently, TM also has some reliability issues under certain circumstances, as well. But then again what software doesn't these days?! I always wonder how robust these backup software are, as they are dealing with vast quantities of data and are often not up to the job (reading about all their failure points can be disheartening!).


Offsite is a pipe dream too. Yes it'd be nice, but for this data size, offsite is more money I simply don't have (I budget for my spending over a period of time), but if I had the cash then of course this'd be a great thing for anyone to do. Although luckily my home is alarmed and has mainline-powered smoke detectors for fire, both connected to a monitoring company, so this will have to do. (yes, I know the argument "how much is your data worth to you?!", but it's not 'business critical' stuff; humans managed to survive losses before we had digital computer data, it's not life or death!)

As for cloud, is there actually a viable option here? AFAIK, there really isn't for home users in most of the developed world for TB's of data, who typically may be on an internet connection like what I have of 120/12mbps (down/up) when working at best on a wired connection (only about half the time, for a number of reasons outside of one's control). The issues are:

1) Data upload. (the main bottleneck!)
Even if you find one of those companies where you ship them your first backup material, if you're backing-up even 5-10 GB's a day after this, it's going to take you WAY too long to make it a viable option. And it hogs the line for other things you may do in the background daily.

2) Data download.
If you have to recover using this cloud backup, downloading TB's of data will also take you AN AGE to do so, again blocking the line for general usage! Although, if the backup company will physically ship you the backup, you may be OK.

3) Cost.
For TB's of data, surely the current cost is also prohibitive for average home users. Both in terms of the strorage volume you need to pay for monthly/yearly (GB per $), and I'd guess extra expensive for any services involving shipping physical items back and forth.


I wish Apple (or someone!) would come-out with an integrated backup service (local & cloud together), able to deal with the TB's of data we're all producing, as this stuff is quite niche for general home users technical abilities, and involves many possible failure points. Sigh.

 

[flynz4]

Time Machine won't do this, as seemingly it won't backup from EXTERNAL to EXTERNAL. If I have it right, TM will only backup the Mac boot drive AND an external (or more than one external) to another backup external (or more than one backup external, if one wants to have rotating backups).



This is not for business, it's home use (video takes lots of space). I bought this space to grow into, i.e. I currently have only ~6TB of data, but worked-out I'll probably need another ~6TB more this year, and then annual growth of ~3TB per year after that. So 6+6 (+3+3, for another 2 years) = 18TB, plus a couple of TB extra in case of overrun for those three years (or perhaps I may get an extra fourth year, if lucky).

This was why I was going to do incremental backups. From reading about Carbon Copy Cloner (CCC) and Super Duper (SD) they both seem to do incremental CLONE backups only; a sort of half-way house solution. As this means it does a mass clone at the beginning, then checks files for changes on the main storage external, and CLONES any new files or changed files to the backup external.

This does not sound the same as Time Machine —which as I said above, won't work anyway, because it looks like it won't do external to external— which if it could, would be better as it would offer file VERSION history, thus any propagated errors could still be recovered from for a period afterwards (until it had to wipe the oldest to make space for newest – 'deltas' I think they are called).
Apparently, TM also has some reliability issues under certain circumstances, as well. But then again what software doesn't these days?! I always wonder how robust these backup software are, as they are dealing with vast quantities of data and are often not up to the job (reading about all their failure points can be disheartening!).


Offsite is a pipe dream too. Yes it'd be nice, but for this data size, offsite is more money I simply don't have (I budget for my spending over a period of time), but if I had the cash of then of course this'd be a great thing to do. Although luckily my home is alarmed and has mainline-powered smoke detectors for fire, both connected to a monitoring company, so this will have to do. (yes, I know the argument "how much is your data worth to you?!", but it's not 'business critical' stuff; humans managed to survive losses before we had digital computer data, it's not life or death!)

As for cloud, is there actually a viable option here? AFAIK, there really isn't for home users in most of the developed world for TB's of data, who typically may be on an internet connection like what I have of 120/12mbps (down/up) when working at best on a wired connection (only about half the time, for a number of reasons outside of one's control). The issues are:

1) Data upload. (the main bottleneck!)
Even if you find one of those companies where you ship them your first backup material, if you're backing-up even 5-10 GB's a day after this, it's going to take you WAY too long to make it a viable option. And it hogs the line for other things you may do in the background daily.

2) Data download.
If you have to recover using this cloud backup, downloading TB's of data will also take you AN AGE to do so, again blocking the line for general usage! Although, if the backup company will physically ship you the backup, you may be OK.

3) Cost.
For TB's of data, surely the current cost is also prohibitive for average home users. Both in terms of the strorage volume you need to pay for monthly/yearly (GB per $), and I'd guess extra expensive for any services involving shipping physical items back and forth.


I wish Apple (or someone!) would come-out with an integrated backup service (local & cloud together), able to deal with the TB's of data we're all producing, as this stuff is quite niche for general home users technical abilities, and involves many possible failure points. Sigh.

At your volume... I agree that cloud backup is not feasible. It is not storage cost (only a couple of dollars/month)... but rather bandwidth.

My current contract with Crashplan+ is $6/month... and I use it to back up 8 different computers. The largest backup set is 1.5TB. It would not work for you.

/Jim

 

[jimthing]

At your volume... I agree that cloud backup is not feasible. It is not storage cost (only a couple of dollars/month)... but rather bandwidth.

My current contract with Crashplan+ is $6/month... and I use it to back up 8 different computers. The largest backup set is 1.5TB. It would not work for you.

/Jim

How long did it take you to get all these computers data uploaded though? Even uploading a gig of data takes ages.

And if one failed, how is recovery handled? I find that at best I get 10GB's an hour on download.

 

[flynz4]

How long did it take you to get all these computers data uploaded though? Even uploading a gig of data takes ages.

And if one failed, how is recovery handled? I find that at best I get 10GB's an hour on download.

Each computer backs up independently... so each completed at different times... each as I purchased new computers.

My most recent backup is 1.5TB. I paid for the seeded backup... but that is limited to a 1TB drive. After compression, I was able to fit 1.2 TB of data. The remaining 300GB took a few extra days.

At this point... all four of us in my family each have an iMac and a MBA. Each of our machines is backed up to our "personal" backup sets in the cloud. We each have an iMac backup, and a MBA backup... with our own personal data.

The best part is that we no longer need to do full backups anymore. As we change machines... we just locally copy our data to our new machine... and then we "inherit" the Crashplan+ backup of our previous iMac or MBA. After a short sync... the computer continues with incremental backups to our existing cloud backup.

It is really quite a bargain to back up 100% all of our personal data... for four family members... each with 2 computers, and each with "unlimited data"... for a grand total of $6/month.

But like I said... it would not work for you with 18TB of data. It is just too much for normal consumer internet bandwidth.

Regarding recovery: We use Crashplan+ for disaster recovery. In the event we need to restore a machine... we would perform a local recovery from Time Machine... not from Crashplan+ TM is fast and easy. In the event our house burned down... destroying our computers + our local backups... then we would need to download the data... or pay for a seed recovery. Not a problem.

/Jim

 

[marzer]

Time Machine won't do this, as seemingly it won't backup from EXTERNAL to EXTERNAL. If I have it right, TM will only backup the Mac boot drive AND an external (or more than one external) to another backup external (or more than one backup external, if one wants to have rotating backups).

I don't understand, you seem to say it won't backup external to external and then go on to explain how it will backup external to external.

Doesn't matter, it will do it, as I stated that is my actual setup. Using Time Machine to backup external to external. I've done this for years with my Mac mini server.

Edit: Or maybe you are not aware that you can exclude the boot drive from the Time Machine backup?

 

[jimthing]

I don't understand, you seem to say it won't backup external to external and then go on to explain how it will backup external to external.

Doesn't matter, it will do it, as I stated that is my actual setup. Using Time Machine to backup external to external. I've done this for years with my Mac mini server.

Edit: Or maybe you are not aware that you can exclude the boot drive from the Time Machine backup?

No you miss understand me here slightly.

What I want to do:
• Mac Mini has both a 256TB SSD and a 1TB HDD in it. I want the SSD boot to backup --> to the internal 1TB.
Also:
• external#1 (main storage), I want to backup to --> external#2 (backup of external#1).

But TM can do one or the other of these, but not BOTH.

I said **IF** you could use Time Machine to back up from JUST the external to another external, whilst having the mac boot drive backup to another internal HDD, then TM is perhaps a better type of incremental backup, as it holds ALL VERSIONS of files (e.g. if you create & edit a file 5 times over a number of weeks/months, it will have saved ALL versions of the file changes you made to the file, so you could access any of the 1st/2nd/3rd/4th versions, as well as the final 5th version). Of course this takes a bit more space than the clone idea below.

Whereas clone apps like CCC & SD do a different thing, as they only update the file to its current state (i.e. you cannot go back into a TM-type file history view, and get, for example, the 1st/2nd/3rd/4th versions, but only the final 5th version it cloned a copy of).

...unless I have it wrong from my reading, but I don't think I have.

Each computer backs up independently... so each completed at different times... each as I purchased new computers...

How good is Crashplan+ I'm wondering, just for the local backup side of things (i.e. regardless of also backing-up to their cloud)? I've only had a quick read to be honest. Does it do local VERSIONING like TM can do, but just doing an external to another external with or without the internal Mini's SSD to HDD?

Sure does sounds affordable though, if you want to pay to get the cloud side of it! Just wondering about the process though, as for multi-TB's of data, it might not be possible to use.

Thanks for responses so far.

 

[flynz4]

How good is Crashplan+ I'm wondering, just for the local backup side of things (i.e. regardless of also backing-up to their cloud)? I've only had a quick read to be honest. Does it do local VERSIONING like TM can do, but just doing an external to another external with or without the internal Mini's SSD to HDD?

Local backup is the same as to the cloud... it uses the same engine. Full versioning.

/Jim

 

[marzer]

No you miss understand me here slightly.

What I want to do:
• Mac Mini has both a 256TB SSD and a 1TB HDD in it. I want the SSD boot to backup --> to the internal 1TB.
Also:
• external#1 (main storage), I want to backup to --> external#2 (backup of external#1).

But TM can do one or the other of these, but not BOTH.

I said **IF** you could use Time Machine to back up from JUST the external to another external, whilst having the mac boot drive backup to another internal HDD, then TM is perhaps a better type of incremental backup, as it holds ALL VERSIONS of files (e.g. if you create & edit a file 5 times over a number of weeks/months, it will have saved ALL versions of the file changes you made to the file, so you could access any of the 1st/2nd/3rd/4th versions, as well as the final 5th version). Of course this takes a bit more space than the clone idea below.

Whereas clone apps like CCC & SD do a different thing, as they only update the file to its current state (i.e. you cannot go back into a TM-type file history view, and get, for example, the 1st/2nd/3rd/4th versions, but only the final 5th version it cloned a copy of).

...unless I have it wrong from my reading, but I don't think I have.



How good is Crashplan+ I'm wondering, just for the local backup side of things (i.e. regardless of also backing-up to their cloud)? I've only had a quick read to be honest. Does it do local VERSIONING like TM can do, but just doing an external to another external with or without the internal Mini's SSD to HDD?

Sure does sounds affordable though, if you want to pay to get the cloud side of it! Just wondering about the process though, as for multi-TB's of data, it might not be possible to use.

Thanks for responses so far.

I get it, you want 2 different backup sets. I've used Chronosync for years as a secondary backup system. It performs conventional backups and incrementals, mirror syncs, or even boot clones. Hence, if desired, provides archives to let you go back and pick out a previous 1st, 2nd, 3rd, etc. version. Although it lacks a slick recovery interface like TM, although that's unique to TM from my experience with backup software.

As I seldom have a need for versioning a boot drive, consider creating a mirror sync of the boot SSD to the internal HHD using a third program. Use Time Machine to backup external #1 to external #2 as that's your main data storage.

Another alternative, as I described with my setup, is to configure your backup drive as RAID 0. Then you'll have 24TB on the backup drive and can backup the whole thing using Time Machine. RAID 5 is overkill for a backup device unless your storing some pretty sensitive or critical information.

 

[jimthing]

I get it, you want 2 different backup sets. I've used Chronosync for years as a secondary backup system. It performs conventional backups and incrementals, mirror syncs, or even boot clones. Hence, if desired, provides archives to let you go back and pick out a previous 1st, 2nd, 3rd, etc. version. Although it lacks a slick recovery interface like TM, although that's unique to TM from my experience with backup software.

As I seldom have a need for versioning a boot drive, consider creating a mirror sync of the boot SSD to the internal HHD using a third program. Use Time Machine to backup external #1 to external #2 as that's your main data storage.

Another alternative, as I described with my setup, is to configure your backup drive as RAID 0. Then you'll have 24TB on the backup drive and can backup the whole thing using Time Machine. RAID 5 is overkill for a backup device unless your storing some pretty sensitive or critical information.

Interesting stuff.
On that RAID 0 point. I understand what you're getting at. It's really a 50/50 trade-off here. While it's good that it'd give me more backup space over RAID 5 (24TB vs. 20TB), but the bad side is that if the backup external does fail, one loses the whole backup set, and has to start afresh by rebuilding from the first main storage external all over again.

However using RAID 5 on the backup external and having it fail, one has more chance of recovering the backup by doing a parity rebuild from the other disks. Of course a second HDD failure in the RAID 5 whilst the rebuild was happening (the stress of rebuild can apparently add to other disks in the set failing) would still result in an entire restart from afresh by rebuilding from the first main storage external all over again.

So the debate for the backup external is: "more backup space, but instant complete restart if fails" vs. "less backup space, but normally a quick recovery if fails, with a lesser chance of complete restart if that recovery fails".


I'm warming to the idea of using TM to backup the externals only, and then just CCC to clone the the Mac Mini SSD.

Then there's the software mentioned: CC, DC, CS, CP+.

DC isn't as good as CCC from my reading, e.g. it does not copy any Recovery HD partitions, for instance.
I wonder what CS does in comparison to CCC?

From reading, CCC sounds popular though, which is often a sign of good things.

Local backup is the same as to the cloud... it uses the same engine. Full versioning.

/Jim

And CP+ adds to the options, adding cloud. Confusing.

Choices choices!

 

[marzer]

Interesting stuff.
On that RAID 0 point. I understand what you're getting at. It's really a 50/50 trade-off here. While it's good that it'd give me more backup space over RAID 5 (24TB vs. 20TB), but the bad side is that if the backup external does fail, one loses the whole backup set, and has to start afresh by rebuilding from the first main storage external all over again.

However using RAID 5 on the backup external and having it fail, one has more chance of recovering the backup by doing a parity rebuild from the other disks. Of course a second HDD failure in the RAID 5 whilst the rebuild was happening (the stress of rebuild can apparently add to other disks in the set failing) would still result in an entire restart from afresh by rebuilding from the first main storage external all over again.

So the debate for the backup external is: "more backup space, but instant complete restart if fails" vs. "less backup space, but normally a quick recovery if fails, with a lesser chance of complete restart if that recovery fails".


I'm warming to the idea of using TM to backup the externals only, and then just CCC to clone the the Mac Mini SSD.

Then there's the software mentioned: CC, DC, CS, CP+.

DC isn't as good as CCC from my reading, e.g. it does not copy any Recovery HD partitions, for instance.
I wonder what CS does in comparison to CCC?

From reading, CCC sounds popular though, which is often a sign of good things.



And CP+ adds to the options, adding cloud. Confusing.

Choices choices!

The way I see it, redoing a backp never seemed that big a deal to me. I still have the primary data set and the mirror set while the backup device is being restored. And with Thunderbolt speeds I can recreate a 2TB data backup in like 4-5 hours after replacing a failed disk drive.

 

[theglobalfund]

Juggling three R6's here..

Hi all, I posted in here about a year ago, concerning the use of two 12tb R6 units I was using, where one would serve as a Time Machine backup of Mac Mini server and the other as an "active" drive which would also be backed up on the TM Pegasus.

It has worked really well for the last year, with multiple users drawing HD DSLR footage from it for multiple simultaneous edits and VFX.

However we have reached our carrying capacity, where TimeMachine no longer has enough room to backup as each backup is too large.

We have just bought a Pegasus R6 24TB unit with the hope that this would fix the problem, but alas things are already looking a little sketchy. For starters, once plugged in, the brand new R6 24TB shows up as a 16TB capacity drive... Now is that because it's formatted to RAID6 rather than RAID5? My understanding is that it should be saving 1 quarter of total space for security, so I should have at least another 2 TB there right?

Secondly, if I'm able to sort out the 24tb unit, I will have 3 units: 1x Active 12TB R6 unit, TM backup unit 12TB R6, and 24TB R6.
Is there a way that I can link or combine the 12TB backup unit with the 24TB new unit to make a 36TB RAID 5 unit? This would really be fantastic. I know very little of RAID setups and I'd appreciate some input.

I look forward to hearing back from anyone who can help.

Best,
David

 

[11201ny]

Interesting thread. I've always used Carbon Copy Cloner, and Chronosync for backup. Perhaps Time machine is a better option for single volume backup?