December 2008 Archives

As I got this HP MediaSmart EX475 I was evaluating my needs for backups.


I decided to follow this guideline:

DUPLICATE:

• Data needs to be accessible from many computers (Music, movies)
  

BACKUP:

• Data is unique (photos)

HP MediaSmart does not duplicate backups, so capacity wise it might be better idea to keep data stored in desktop or laptop and just store backups to HP.

So - what is real difference between duplication (+RAID) and backups?

Well, it is restore. With duplication or raid you can not restore anything. This might be okay if you handle backups some other way. Maybe your strategy is to copy duplicated shares annually to external USB disk and move that disk to offsite, maybe bank.

Simple way to evaluate if you can duplicate or need to backup data: do you need ever to restore data - what if someone deletes file/subdirectory or software you are using is actually corrupting data.

It is really tempting to leave the data only as duplicated as it is already secured to the 2 separate disks and usually wanting to have flexible way to access the files using multiple computers.

I had an opportunity to buy this storage server with a pretty good price. Originally I was planning to have a network storage and I tried to avoid extra administrative work needed to run such service. I knew this HP server could be pretty OK for my purposes but I did not know how disk management etc was handled on it.

I have been working closely with different raid levels, different operating systems etc and I was a bit surprised how Microsoft has approached this issue. I did not see any hardware or software raid on this unit, but each physical disk is part of storage pool. It is possible to have data secured (single file physically on 2 disks) or then leave data unsecured - this security issue is handled on share level.


This (file) mirroring approach is pretty flexible and does not have really administrative work. If you run out of disk space, it is possible to remove smaller disks from system and install bigger ones. During this part you probably can add some USB disk(s) to server so you do not loose security level (data mirroring). There is no need to keep disks identical as there is no RAID used. All disks can be different size and it is still okay.




Downside of this mirroring approach is that as we mirror only files and you can't be sure where your data is really located. Every file is located on two disks, but I did not found documentation about how server choose where to store data. If I am correct, you can loose only one physical disk without loosing the data (if all shares have this mirroring enabled) - similar as RAID5 ... but capacity wise you will loose 50% of the disk capacity to mirroring - similar as RAID1. In other words, there is all bad things chosen from the RAID5 and RAID1 but due this approach this works pretty well at home because we achieve really flexible and zeroadmin device.




As I have also XBOX360 at home, I tried to use it to access media on storage. Music was easy, XBOX handled MP3 files without problems. Videos were also pretty easy, but as there is so many different codecs available some of videos just did not work on XBOX.


Storage itself is not quiet as there is 2*80mm fans, but it is not too loud either. I must say, I really like all functionalities this system provides.

For some reason you need to have at least one Windows workstation running (32bit) while doing initial setup.