Raid 1 or Raid 5

[LukeC]

hello, im about to pruchase a new physical domain controller, what woudl people go for Raid 1 or Raid 5, it wont store any data just will be a Global catalog server, DNS, DHCP thanks

[localzuk]

For a DC? RAID 1.

[tmcd0035]

I generally work to the following rule of thumb - Operating Systems either JBOD or RAID1, Data preferably RAID-5 but sometime RAID-10 if cost is an issue. In this case I'd go RAID-1, personally.

[jamesfed]

How many disks and at what speed is a thing to think about first....

Otherwise pretty much the same with me as @tmcd0035 - RAID1 for anything that is OS related and then RAID5 for data.

If you aren’t using your server to store data (other than your AD) just RAID1 would be fine.

[bossman]

Ditto Raid-1 for what you require

[LukeC]

thanks

[Michael]

RAID 1 for OS, RAID 5 for data or RAID 5 for OS and data (partitioned) is how I do it.

[broc]

Trying not to hijack the thread, but what would you recommend for a Hyper-V host OS? Our existing ESX hosts are RAID 1, when we move to Hyper-V I am torn between leaving them at RAID 1 or moving to RAID 10? User data & VM OS would be on a SAN so this is purely for the Host OS itself.

[tmcd0035]

RAID 1 for OS, RAID 5 for data or RAID 5 for OS and data (partitioned) is how I do it.

Accepting that every network/need is different - I'd normally argue, with the price of 250Gb hard drives being what they are, I'd sooner a seperate (non-RAID) drive for the OS to partitioning a RAID-5. I think the partitioning would have a (negligable?) impact on data access speeds.

[bwestlake]

RAID1 for os maybe RAID0 as a dc replacates itself, for data RAID5 or RAID6

[tmcd0035]

Trying not to hijack the thread, but what would you recommend for a Hyper-V host OS?.

Ours are all RAID-1 (guests are on a RAID-50 NAS). Cant see the OS being hammered enough to justify the extra cost of RAID-10.

[SYNACK]

Trying not to hijack the thread, but what would you recommend for a Hyper-V host OS? Our existing ESX hosts are RAID 1, when we move to Hyper-V I am torn between leaving them at RAID 1 or moving to RAID 10? User data & VM OS would be on a SAN so this is purely for the Host OS itself.

Why not dump the VMs on the SAN to? That way you can use shared storeage if needed. You'll need to have the iSCSI extentions so that the NICs can act as HBAs but this is included with many newer servers and removes the drives entirely from the servers, if you want more speed use the extra money that you were looking at for a 1+0 upgrade to chuck an extra few drives in the SAN in a drive shelf if there is no extra room.

[tmcd0035]

RAID1 for os maybe RAID0 as a dc replacates itself, for data RAID5 or RAID6

For a DC I'd see RAID-1 as worth it just so you can try to avoid having to bring up a new DC from the replication. Removing a dead DC from DNS is cumbersome to say the least.

[Michael]

Accepting that every network/need is different - I'd normally argue, with the price of 250Gb hard drives being what they are, I'd sooner a seperate (non-RAID) drive for the OS to partitioning a RAID-5. I think the partitioning would have a (negligable?) impact on data access speeds.

I'd never have a server OS on a non-RAIDed drive personally. There are good reasons why partitioning a RAID5 array is a good idea.

Firstly, if you need to re-install the OS or restore from a backup, user data will remain untouched as it's on a different partition. If it was all on the same partition, it would get extremely complicated.

Other reasons are for storing WSUS files 20GB+ and image files, which are typically 20-30GB which leads me onto the next point -

2008 R2 backs up whole volumes rather than individual files/folders, however you can restore individual files/folders as required. Partitioning gives me redundancy, but still allows me to organise and backup data in an efficient manner.

[SYNACK]

2008 R2 backs up whole volumes rather than individual files/folders, however you can restore individual files/folders as required. Partitioning gives me redundancy, but still allows me to organise and backup data in an efficient manner.

R2 does have a better backup that can target files and folders and shove them into VHDs, 2008 is limited to drives or predifined stuff like system state only. I still end up using robocopy thanks to the impotence of the new backup tools if at a smaller site.