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Time Machine vs RAID 1

Related to data-corruption and the like: make sure that you can actually restore data from the backups. I remember one horror-story from one company that diligently backed up their data to tapes. Then they suffered a catastrophic failure on their server. When they went to restore the data from the tapes, they noticed that for the last six months, the backup-software's log was filled with error-message saying "Cannot write to tape"....
 
jtblueberry said:
EDIT:

I have always kept one backup of my photography files on an external hard drive. Now that I am moving to Lightroom from Capture One I am finding there are many more things that need to be backed up.
Right now, I have my system set up like this:
500GB boot drive backed up by 500GB external firewire drive.
1TB "photography drive" backed up by matching 1TB drive in an external eSATA enclosure. I am using Time Machine for that.
I guess the question now would be is it worth the extra cost of a third back up (2 hard drives in my case)? If so, I could use the third drive as a second back up but what would be best:
1. 2 working drives in raid 1 with 3rd drive as time machine backup
2. 1 working drive with 2 time machine backup drives in raid 1
3. 1 working drive with 2 separate time machine backup drives

I should mention that I will go through at least 1TB of storage per year. I am using Seagate Barracuda 7200.11 1TB Hard Drives that cost $320 each. I will replace my photography hard drive and backups of the photography hard drive each year but my boot drive and boot drive backups will not be replaced.

I don't have the luxury of investing in expensive hardware raid set ups as I do want to keep as much money in my pocket as possible. I'm pretty meticulous and haven't lost anything to speak of in over 5 years of digital photography so I want to be safe but don't want to break the bank doing it.
Click to expand...

Your biggest risk at this point seems to be a single physical location. One burst pipe in a ceiling could be really bad. So unless your backup drives are stored in a second location and you can add to them via CD/thumb drive/CF card/whatever then that's where you should put your energy. It's relatively rare to lose a drive to a head crash- let alone two independent drives- so you're looking at recoverable data unless two drives go at once. I've seen lots of two drive RAID1 and RAID 5 failures that resulted in having to restore from tape. RAID 1 where you pull a fully-built mirror out, move it offsite and replace it with a clean drive and let the mirror set rebuild isn't the worst backup strategy in the Universe- and since you're pretty much looking at an all-or-nothing data strategy, there's not a great deal of advantage to a point-in-time backup strategy other than not having to duplicate all the data. SuperDuper!- the registered version can do that, but that doesn't help you get the whole thing offsite. If you're constantly moving drives on and off-site to synch, then you'll either need 3 drives and the discipline to not bring the offsite copy home until you're done moving the newest drive offsite, or 4 drives so one's always off-site and you'll just risk the delta between offsite moves.

Software mirroring is slow- really slow, so if you want to offsite a mirror copy, then you're probably best off building a server with hardware RAID since all the home/SMB raid boxes do software RAID.
 
jtblueberry said:
Sounds like you came to the same conclusion I did. That's what i'll be doing except when the TB drives fill up, i'll store them and get new ones (I expect that to happen about once per year which works out great). If I get a re-order from the old drive i'll plug one in, do what I have to do, and put it back into storage. I'll store one copy on-site and one copy-off site. I can rotate my old drives out for storage and move new drives into their place (that way no drive gets used for more than about 2 years).
Click to expand...

i am not talking about security here because that has been well covered, however you seem to be wasting a lot of money on external HDD when I think you could save some of your hard earned penny's on regular desktop HDD's.

if you're going to do swap out hard drives frequently then i think a multiple hard disk array would be beneficial to you. Maybe something like the
DROBO http://www.drobo.com/ which lets you hot swap any SATA HDD you want (and do RAID "like" processes) or maybe even something like this
http://usb.brando.com.hk/prod_detail.php?prod_id=00466 which i stumbled upon the other day.......
 
I have to first admit that I have not read every comment in this thread.

But I do want to add one small item. If a drive is always online, then it is NOT backup.

If you use a HD for backup, it needs to be taken off line and stored somewhere safe when it is not actually being used for backup.

By offline, I mean no connection to computer, network, or power. The problem is that viruses or trojans (please dont give me the mac is immune story. If you have a PC on your network and your NAS is network attached, you can be affected by that "chanel".)

Also, power problems can take out your computer. And if your drive is also connected, it may be taken out also. I dont care if you have a UPS on the drive and computer. Is your phone line protected? Cable modem?

The botom line is that if you really value your content, the drives should not be online. With a drive enclosure and 500 gb hd purchased from NewEgg for about $130, you have yourself a real backup.

Better yet, get two and alternate backups.

Don
 
LAPTOPODO said:
What about RAID 1 (by hardware) and Time Machine?
Click to expand...

Common cuases for loss of data are

  • Fire, flood or other disaster
  • Theft of the equipment
  • Operator error (deleteing all or parts of a file and knowing it until weeks later
  • Software error, the "Save" funtion corrupts a file

I don't see how RAID helps with ant of this. The only thing that will is to do both of these:

  1. Take a copy of the data to another building the farther away the better
  2. Alway use incremental backups, never write new backup over top of the old backup data

In addtion have it planned so that if any copy of your data fails you still have a copy of your data in two different locations. In other words the above two condiotions must allways hold, even when writeing a backup and after a failure. This pretty much means you have three copies or even four or maybe network connected off site backups. Any plan that does the above two things even in the worst case.

Simple plans like using Time Machine will work for years. But if you want the data to last for decades, then you have to wory about things that only happen once every 50 years, very low probability events like house fires and the like

My guess is that in 100 years there will be very few 100 year old photos.
 
Time Machine

I use a mac mini server attached to a Time Capsule airport network. Server is backed up via Time Machine hourly as are all desktop and laptop macs –*Each day I rotate 2x external drives with incremental Synced back up and take offsite so absolute worse case we could be out by a day...
 
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