SAS/SFF hard disks and ULTRIUM tape

[Filippo Ranzani]

Hi.

I need to buy a new HP Proliant ML 370 tower G5 server (the new domain controller/A.D. w2k3 server standard in a 30 PCs client LAN).
The server has this hardware (that I don't know at all):

- the disk controller is a "HP Smart Array P400/256MB Controller (RAID 0/1/5)" (with BBWC 512 Mb expansion), with 2 x 72 Gb SAS/SFF hard disks and 2 x 146 Gb SAS/SFF hard disks (all 2,5'' disks)
- with above 4 disks I'll do 2 RAID1 set (2 logical volumes): the first will be C: (S.O.), the second will be D: (datas)
- the internal tape is a "HP ULTRIUM 448 DW016A" with a SCSI U320 controller

Now my questions:

- are the SAS/SFF 2,5'' hard disks safe and reliable as the old SCSI disks ?
- is it correct to do 2 RAID1 set as explained above ? (is it a "best practise" ?)
- is the ULTRIUM tape reliable and safe as the DLT tape ?

Thanks to all for the patience.
Filippo.

[Marek Nelec · Accepted solution]

Hello Filippo

1) Time will tell if the 2.5" SAS HDDs are as reliable as old SCSI drives, but I guess they will. They use less power, generate less heat and less vibrations, and they make much less noise.

2) It is absolutely correct to do 2 RAID-1 sets, althouth I usually use additional hot-spare drives. Hot-spare can cover both RAID-1 sets, but in your case it should be 146GB drive. You can use this document to see functions and limitations of various RAID schemes:
http://h20000.www2.hp.com/bc/docs/support/SupportManual/c00386950/c00386950.pdf

3) From my experience I can tell that Ultrium drives are MUCH more reliable DLT drives. At least than 20/40, 35/70 and 40/80 DLT drives - 15/30 DEC models are really tough. And the drive you mentioned supports One-Button Disaster Recovery feature and comes with HP Data Protector Express Single Server Edition Software, which has already licensed feature for creating OBDR bootable tapes.

[Basil Vizgin]

Can confirm at own experience that Ultrium is much reliable than DLT.
As you use not all of drive bays you can use internal SAS tape drive: DW085A Ultrium 448 SAS Internal Tape Drive.

[Filippo Ranzani]

Thank to Marek and Basil for your kind reply, you are very very fine.
You explained me some features that I didn't know before, thank you!

A little clarification about the ULTRIUM reliability: your phrases "Ultrium drives are MUCH more reliable DLT drives" and "Ultrium is much reliable than DLT" mean that Ultrium drives are much more reliable than DLT drives, correct?

Thank you very much for your help and patience.
Bye bye, Filippo.

[Marek Nelec]

Sorry , I've missed a word :). Yes it should read: "Ultrium drives are MUCH more reliable _THAN_ DLT drives". And BTW they have better head cleaning design, so they don't require regular cleaning, as DLT drives did. You can read this doc, if you to want to know more about it:
http://support.overlandstorage.com/jive/servlet/KbServlet/download/2383-102-63/LTO_Cleaning_wp.pdf

[MSECO_1]

I am tape support engineer from HP and I recomend ultrium drives for medium and large enterprise business and DAT for small business.
DLT and SDLT have many issues.
Try Ultrium 960 (LTO3) with U320 SCSI controller.

[Basil Vizgin]

Our clients have many issues with DLT in the past: we regularly remove tape leader from the drive, etc.
May be with latest generations of DLT something changed, but I don't know--we completely switched to DAT/LTO(Ultrium).
MSECO, why not to propose Ultrium SAS solution?

[Marek Nelec]

Basil, U320 PCI-X SCSI HBA is still cheaper than SAS or U320 PCI-E SCSI HBA.

[Filippo Ranzani]

Thank you very very much for all the answers and the documentation about my problem.
You are very kind and qualified, and also patient.
Now I'm sure about the new server i'm going to buy.

Thanks to all for your kind help.
Bye bye, Filippo.

[Marek Nelec]

Glad to help :)