topic Re: DL380 and RAID --one missed question in ProLiant Servers (ML,DL,SL)

DL380 and RAID --one missed question

scott_417 — Tue, 18 Oct 2005 14:57:21 GMT

What is the Advanced Data Guarding? How is it compared with the RAID x?

Thanks.

Re: DL380 and RAID --one missed question

Steven Clementi — Tue, 18 Oct 2005 15:02:41 GMT

Scott:

RAID ADG is similar to RAID 5 - Parity is striped among all the drives. In this case though, you lose the space of 2 drives instead of 1 as in RAID5.

On a Dl380 with 6 disks, your available space for RAID ADG would be equal to 4 disks.
RAID 5 would be 5 disks.
RAID1+0 would be 3 Disks
RAID 0 would be 6 disks.

RAID ADG is slower performing than RAID5 since it is writing 2 stripes of data instead of 1. You can lose up to 2 disks though and still be operating vs. 1 disk with RAID 5.

Steven

Re: DL380 and RAID --one missed question

Ivan Ferreira — Tue, 18 Oct 2005 15:14:39 GMT

I prefer RAID 5 with SPARE insted of RAID ADG. This is for performance.

You can loose anyway too disks, but not at the same time, when you loose a disk, the spare disk will reconstruct the data of the failed disk. After the reconstruction, you can loose a disk again.