RAID for OS or for Data disks??

itdaddy

Hey raid gurus!

I always thought you would put raid for only data partitions of Data disks not OS disks.


I went to this bank and they had a raid set of 3 disks and the IT guy said when 1 drive failed
that the system no longer ran. To me that says his raid set was set up for both data and os am i correct.. I didnt look at it but seems by what he said was th cause....we have at my work
and OS on 1 disk by itself and our data is always on raid....can someone enlighten me on this...

and what do you think? about this IT guy pulling one disk out and the machine didnt run at all
i mean didnt function the OS i mean. what do you think?

this place was pretty bad andthey really didnt have a clue

dynamik

I don't know why you wouldn't want to use a RAID array for your OS drives as well. I have all my OS drives in RAID-1. I don't want to have to reinstall, reconfigure, or restore anything just because one drive dies. I have my data on RAID-5.

It sounds like the bank was using RAID-0, which isn't really RAID. They shouldn't lose functionality if one disk fails; the entire purpose of RAID is to prevent that.

Smallguy

we RAID 1 or OS drives and RAID 5 the data drives on any critical servers where I work

itdaddy

SmallGuy and Dynamik
you guys are right on!
yeah that sounds right ; i was thinking about it having RAID 0 that would explain why it died
when one disk failed ai gree..i have never done OS with raid1 which if it works like you say
then i agree perfect setup for system! raid 1 for OS adn raid 5 for data or raid1 would be good too..nice thanks kind what i thought just we never did raid 1 with OS which i do believeis common. i just would image the os onto the raid 1 data drive and if need be blast it back on but your idea with raid1 is much better and keeps os current right on buds!
thank you!

bighornsheep

itdaddy wrote:

I went to this bank and they had a raid set of 3 disks and the IT guy said when 1 drive failed
that the system no longer ran. To me that says his raid set was set up for both data and os am i correct..

It might not necessarily have been a RAID system, a few vendors of enterprise server computing sells solutions which implement something called single level storage where the entire collection of disks are treated as ONE single disk on the hardware level, this is NOT RAID-0 because even the I/O of single level system sees the disks as one, not just the OS.

dynamik wrote:

It sounds like the bank was using RAID-0, which isn't really RAID. They shouldn't lose functionality if one disk fails; the entire purpose of RAID is to prevent that.

The reason why the bank would want to do this is for security, if someone stole a disk in a RAID-array, they can still technically recover parts of the data, or partial files. If they are using single level storage as I suspect, there is no way at all to recover anything meaningful even if they have a few of those disks, they will need the entire SLS to recovery something.

The benefit of RAID-0 is in speed, if you implement RAID-0 consisting of disks which are in single level storage systems, you have the best of both worlds.

ilcram19-2

i agree having a mirror on the OS but RAID 5 on data i dont think would be a googd idea specially for the write/read performance get a 2 15k rpm drives and mirror, or my favorite set up a mirror of stripes this will include speed and foult tolerance

ilcram19-2

dynamik wrote:

I don't know why you wouldn't want to use a RAID array for your OS drives as well. I have all my OS drives in RAID-1. I don't want to have to reinstall, reconfigure, or restore anything just because one drive dies. I have my data on RAID-5.

It sounds like the bank was using RAID-0, which isn't really RAID. They shouldn't lose functionality if one disk fails; the entire purpose of RAID is to prevent that.

lol are you serius you may need to do a research of what u just wrote lol

dynamik

ilcram19-2 wrote:

lol are you serius you may need to do a research of what u just wrote lol

Care to elaborate?

bighornsheep

dynamik wrote:

ilcram19-2 wrote:

lol are you serius you may need to do a research of what u just wrote lol

Care to elaborate?

For those that wanted some details, quite frankly I don't remember where I know it from, possibly a systems architecture textbook or similar. However, I did find that IBM's iSeries has this implementation.

http://www-03.ibm.com/servers/enable/site/porting/iseries/overview/overview.html

sprkymrk

ilcram19-2 wrote:

dynamik wrote:

I don't know why you wouldn't want to use a RAID array for your OS drives as well. I have all my OS drives in RAID-1. I don't want to have to reinstall, reconfigure, or restore anything just because one drive dies. I have my data on RAID-5.

It sounds like the bank was using RAID-0, which isn't really RAID. They shouldn't lose functionality if one disk fails; the entire purpose of RAID is to prevent that.

lol are you serius you may need to do a research of what u just wrote lol

What are you laughing at or referring to in dynamik's post?

RAID-0 is striping w/o parity, which makes it faster, but NOT redundant. If you lose 1 disk you've lost it all.

itdaddy

bighornsheep

you mean like JBOD? or something like Spanning disks across all three...weird...
I guess for speed but who gives a rats arse it is a file server and I am betting it is used
as DNS and DC as well but I might get to look at it soon and will definitly tell all what it is..
the guy was shocked but has done nothing to fix it...so stuff like that just left alone and to say oh well..these guys need help. anytime i see stuff like that i dig right and will fix that bad boy to someting right! ;)and this is a medium size bank and IT department amzing at best!

snadam

sprkymrk wrote:

ilcram19-2 wrote:

dynamik wrote:

I don't know why you wouldn't want to use a RAID array for your OS drives as well. I have all my OS drives in RAID-1. I don't want to have to reinstall, reconfigure, or restore anything just because one drive dies. I have my data on RAID-5.

It sounds like the bank was using RAID-0, which isn't really RAID. They shouldn't lose functionality if one disk fails; the entire purpose of RAID is to prevent that.

lol are you serius you may need to do a research of what u just wrote lol

What are you laughing at or referring to in dynamik's post?

RAID-0 is striping w/o parity, which makes it faster, but NOT redundant. If you lose 1 disk you've lost it all.

+1

keyword: REDUNDANT

itdaddy

yeah thanks
i have just seen our new Evault system server with Raid 1 on 2 drives for OS
and RAID 6 for 8 drives. you can lose 2 drives in our raid 6 and still works great.

freaking awesome!

yeah i see for super dooper system you need to have the OS on a raid 1..I still think
imaging the OS is still essential because what if you get a corrupt OS later on. it only mirrors
on both drives then both are corrupt! So i usually image a base OS and keep imaging updates every so often after major changes! it is work but man can it save your Arse!

and i image 2x...twice is nice!

emmajoyce

we use Raid 1 for OS on our servers at my work, We are a large bank

totalfailure

RAID 0 shouldn't be classed as RAID, but AID!