[DM-MUG] Backups (in response to the Danger/Sidekick Fiasco)

[Ray Bowler]

Jon,

Thanks for the info.

Ray
On Oct 13, 2009, at Oct 13, 20091:06 PM, Jon Thompson wrote:

> Victoria alluded to this in another post, but it requires some  
> further explanation...
>
> The fiasco with the Sidekick phones is apparently a result of poor  
> planning on the part of Microsoft, and their SAN integrator- Hitachi.
> (As a side note, I am a SAN admin, so I deal with these technologies  
> on a day to day basis.)
>
> Apparently Hitachi was updating the Storage Area Network (SAN,)  
> which went south. Microsoft then went to their backup of the data,  
> which was also corrupt. Updating a SAN is a relatively risky  
> procedure, often requiring zero corruption on many tens of Terabytes  
> of data. Because of this nature, it is imperative that a good backup  
> is performed, as a heavily corrupt SAN is usually unrecoverable (a  
> single file can be spread between not only many hard drives, but  
> many devices.)
>
> This provides the opportunity to talk about backups a bit...
>
> 1) A good backup is a verifiable backup
>
> If you are dumping info into Time Machine, and you are _never_  
> pulling info back out of it and checking, how do you know that the  
> data is good? In the instance of the SideKick data, this means that  
> they would have known that the backup is good, and that they could  
> rely on it. Until you know that you can recover from it, you cannot  
> call it a good backup.
>
> 2) A good backup consists of many backups of the same data.
>
> I store three months of backups, and I consider that too little, but  
> don't dare increase my budget. If you are relying on all of your  
> data being on a single hard drive, what happens if there is a fire  
> and both your computer and backup is lost? If all of your backup is  
> in one cloud (Mozy) and that cloud bursts like the SideKick cloud  
> did, you are hosed. Now, if you have daily backups on a time machine  
> volume, and a weekly backup to Mozy, you are protected from either  
> example. Mozy is your offsite backup, the time machine
>
> 3) Synchronization is not backup.
>
> Synchronization ensures that all of you data is the same between all  
> instances that you create. If you are syncing your address book on  
> your mac with an iPhone, you have two instances of the data, but  
> they are tied together. If you delete a contact on one (or a virus  
> deletes all of them) that deletion is transferred to your backup. I  
> realize that there are ways that the sync service tries to reduce  
> the chance of this, but it is still a possibility. However, an  
> offline copy of your address book on a USB thumb drive that is not  
> plugged into your computer cannot not be changed, at least until it  
> is plugged in again. Dropbox is a synchronization service.
>
> Part of the Sidekick debacle is because it is apparently a  
> synchronization service. They are telling people not to power down  
> their phones, because it apparently wipes the internal memory and re- 
> downloads content from Microsoft servers. Of course there isn't any  
> data to re-download...
>
> 4) RAID is not backup.
>
> RAID (except 0) is a way to protect from hard drive crashes. It does  
> not protect from application corruption, accidental deletion, or  
> intentional deletion. All of which are much more likely than hard  
> drive corruption during the majority of the life of a hard drive.  
> RAID is useful for server admins that deal with distributing data  
> amongst many hard drives, which actually is a great way to  
> exponentially
> increase the likelihood of data loss due to hard drive failure.
>
> RAID 0 offers no protection at all- in fact, it is will  
> exponentially increase your likelihood of data loss due to hard  
> drive failure. Be careful when purchasing large external hard drive,  
> as they are sometimes two drives that are internally configured as  
> RAID 0. This is useful for professional video primarily.
>
> 5) Backup as sparse as you are willing to recover from.
>
> - If you couldn't stand losing more than a week's worth of data,  
> you'd best be backing up weekly.
> - If you couldn't stand losing more than a day's worth of data,  
> you'd best be backing up daily.
> - If you couldn't stand losing more than an hour's worth of data,  
> you'd best be backing up hourly.
>
> You know what is important and what is not. Make sure to taylor your  
> backup routine to your needs. Incremental backups, such as Time  
> Machine are good about this.
>
> 6) Recovery options are available, but expensive.
>
> Data recovery costs a minimum of $1000 for a hard drive. And they  
> don't guarantee they can recover anything.
>
> -- 
> - Jon
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Ray Bowler

rbowler.home.mchsi.com