Advanced network storage..raid...etc

[k.jacko]

One for the networking/storage gurus here.

My work network consists of:
30+ pc's
4 servers (1 server has built in LTO tape drive)

Backup
Every monday morning i do a weekly backup of the whole system, which uses 5 x LTO tapes (over 500Gb) and takes until wednesday pm to complete. We do not have a jukebox so it waits for me to change the tape (major ball-ache) From then on until friday its just daily incremental backup using veritas backup exec.

As part of our Disaster Recovery Plan, i'm thinking of implementing onto the network the following:
bare bones pc tower, with 4 x 750Gb WD Cavier sataII hdd's each in a hotswap sata caddy. So i can take one out and off the premises when its finished backing up.
So, monday evening (as opposed to morning) start the backup. Hopefully its done by tuesday am and i can take the drive out and off site.
Tuesday evening set the backup to 'image' each server state, so we have OS resiliency if something goes wrong (as well as bog standard data backup on disk from the previous night).
The following week, we use the other 2 drives to perform the same backups, so we have a rotating 2 week system.

Now, we have a 4 disk raided 0+1 nas box in our other office, but the drives aren't hot swappable so i think that option is out the window.
Does this sound like a plan to any of you guys?
What would you do different in this situation?

Thanks for any suggestions.

 

[Nodsu]

Sounds like a good plan.

Some things to note:
- Would your network/servers be able to handle the data? You should test for speed first.
- You are backing up for disaster recovery only? You don't see the need for long-term archiving because of state regulations or just in case that someone returns from the holidays and says that they need a file that was deleted a month ago?
- Is your backup software capable of doing this? You may need to purchase additional licenses.
- How about upgrading the tape drive? LTO-4 tapes can hold 800GB of data uncompressed and are faster than hard drives and gigabit ethernet.

 

[k.jacko]

- Would your network/servers be able to handle the data? You should test for speed first.

I flippin hope so. We essentially have a 100/1000Mbit network, with 4 servers (Dell and HP) all 3GHz dual xeons all with 4Gb ram.

- You are backing up for disaster recovery only? You don't see the need for long-term archiving because of state regulations or just in case that someone returns from the holidays and says that they need a file that was deleted a month ago?

We have an external hdd that once projects are completed are archived onto this periodically.

- Is your backup software capable of doing this? You may need to purchase additional licenses.

Veritas BackupExec, shouldn't need extra licences, its still licensed to run from 4 servers, its just going to be pointed to a different backup medium.

- How about upgrading the tape drive? LTO-4 tapes can hold 800GB of data uncompressed and are faster than hard drives and gigabit ethernet.

Its certainly a consideration. But being prompted to change the tape when its full drastically slows down the backup process. Unless we buy a jukebox/autoloader, but they aint cheap. We use LTO tapes with 200Gb capacity each. Weird thing is it takes 5 tapes to backup just under 600Gb. I don't think it is comrpessing the data.

Thanks for your input nodsu, your advice is most appreciated.

 

[k.jacko]

Something i forgot to mention in that last post:

We don't have a true backbone to our nework. Our server are connected on a 100base switch, not a dedicated managede gig switch as you'd expect. This may have something to do with the constant 'disconnections' we get during the day whilst users are on terminal services. So at times our network is hellish slow.
Another thing i need to get sorted.
Also; is it possible to use raid 1 on 3 hot swap drives, and change one out after the backup, and swap it for an identical drive?
ie. drive A holds all the data we use daily. Drive B is raided for mirroring drive A. So at night after the working day is done, take drive B home and replace it with drive C which then mirrors drive A the following day, then again at night swap drive C for drive B? If this is possible then it eliminates the need for a nightly scheduled backup by veritas. Make sense? If so, please explain it to me, lol.

edit: wonder if this would be any good.
http://www.overclockers.co.uk/showproduct.php?prodid=HD-073-LC&groupid=701&catid=14&subcat=707

 

[Nodsu]

100Mbit network gives you some 10MB/s. A gigabyte copies in ~1.5 minutes, 500GB in 13-15 hours? You need to upgrade your network to move such amounts of data in reasonable time.

Yes, you can do this RAID thing in theory, but it's way too dangerous. You have to power off the server every time to have the disks in a consistent state and the RAID rebuild would take a long time, degrading server performance. Not to mention that if anything goes wrong during the rebuild, you lose all the data.

 

[k.jacko]

bugger! didn't realise that, thanks for the advice. Tis a pity that could have save me some hassle. Instead it seems it would cause more....
So, it looks like i'll have to look into an unraided nas with hot swappable drives, or look at autoloaders for the LTO tapes.