kam_uk
asked on
RAID 5 and RAID 1 question
Hi
We have a server that has 5 SCSI disks.
Normally, we create one RAID 1 mirrored paired for the OS (disks 0 and 1), and then the remaining 3 are used in a RAID 5 setup for the application.
However, I was thinking about this....what's the actual advantage of having the OS on a mirrored pair. Surely, if all 5 disks were in a RAID 5, then we could lose one anyway? Why the seperation?
Secondly, can one Array Controller service as many disks into different RAID configurations as needed? I.e. will one Array Controller be sufficient for the above in a RAID 1 and RAID 5 setup?
Finally, out of RAID 1 and RAID 5, which one is better for an application that writes a lot, and which one is better for an application that reads a lot?
I'm not a hardware person at all, so any help appreciated.
We have a server that has 5 SCSI disks.
Normally, we create one RAID 1 mirrored paired for the OS (disks 0 and 1), and then the remaining 3 are used in a RAID 5 setup for the application.
However, I was thinking about this....what's the actual advantage of having the OS on a mirrored pair. Surely, if all 5 disks were in a RAID 5, then we could lose one anyway? Why the seperation?
Secondly, can one Array Controller service as many disks into different RAID configurations as needed? I.e. will one Array Controller be sufficient for the above in a RAID 1 and RAID 5 setup?
Finally, out of RAID 1 and RAID 5, which one is better for an application that writes a lot, and which one is better for an application that reads a lot?
I'm not a hardware person at all, so any help appreciated.
SOLUTION
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
SOLUTION
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
ASKER
Also, Prelude218, you say
"Back in the days of NT4, this was a common setup, OS on one partition and data and programs on another partition (or raid set). "
So, what has changed? Why is this not a common set up anymore?
"Back in the days of NT4, this was a common setup, OS on one partition and data and programs on another partition (or raid set). "
So, what has changed? Why is this not a common set up anymore?
Raid 5 is way faster for reading and writing.
Simply put, if you are spreading data over say...5 different HDD's and you want pieces off each HD, you will get that information 5x faster because it doesn't have to wait for the first piece to access the second piece, it can access both pieces at the same time
Simply put, if you are spreading data over say...5 different HDD's and you want pieces off each HD, you will get that information 5x faster because it doesn't have to wait for the first piece to access the second piece, it can access both pieces at the same time
ASKER CERTIFIED SOLUTION
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
SOLUTION
membership
This solution is only available to members.
To access this solution, you must be a member of Experts Exchange.
ASKER