what to look for in a raid drive

[xr4man]

ok, i thought i knew a little somthin' somethin' about raid, but now i'm reading about TLER and CCTL and stuff like that. i'm seeing stuff about those things being turned on and off and it's getting confusing to me.

so what should i look for in drives that i plan on raiding together?

[Airbozo]

ok, i thought i knew a little somthin' somethin' about raid, but now i'm reading about TLER and CCTL and stuff like that. i'm seeing stuff about those things being turned on and off and it's getting confusing to me.

so what should i look for in drives that i plan on raiding together?

It depends.

If you are building a rock solid departmental server which requires minimal down time and ultimate performance, never use the consumer grade drives.

If it is a non-critical server, then don't worry too much about it. Just make sure all of your drives are the same or similar.

[xr4man]

ok

it's going into an internet radio server for a friend.

i wanted to do a raid 5 , but i'm starting to think that just raid 0 with an external drive for backup should be fine.

[Fuganater]

RAID 5 will give you better performance.

[xr4man]

yeah that is true. i think that and the ability to have a drive failure was why i wanted to go with raid 5 in the first place.

[Airbozo]

If you have the drives, I would do a raid 5, assuming the controller supports it. I would still do backups though. (but then again I am old school and have redundant backups of every critical piece of my data on HDD's, Tape and dvd's).

[mDust]

RAID 5 will give you better performance.

Actually, RAID 5 has to write extra parity data whereas RAID 0 does not. If you had 3 drives in RAID 0 and 3 identical drives in RAID 5, the 0 array would perform better. RAID 0 should not be used for anything critical as it has no fault tolerance or means of data recovery. If one drive dies, the array is broken and all data is gone. The RAID 5, which does perform much better than a single drive, but not as well as a 0, can survive a single drive failure. I've heard of cases where identical drives that had never been powered on before being put in an array started failing in short succession since they wore identically over many years of use...just something to take into consideration. No RAID array (except maybe a stupidly large RAID 1) is invulnerable and backups should still be performed.

[Fuganater]

If your data means anything to you and it is accessed alot then you should be using RAID 5.

[xr4man]

ok, so, would some caviar blues be ok for a raid 5 or should i tell him to bite the bullet and shell out for caviar blacks?

of course i think i already know the answer.

[Airbozo]

BTW: THIS (http://raid.com/raid) site is where I send everyone for information on how the different raid levels work.

[xr4man]

yup, i saw that site when i was searching for info on raid drives here. everything up to raid 5 i already knew. i couldn't find any info on what drives to actually use though other than the professional drives were best, but they were out of the budget. since this isn't a mission critical server, just don't want any dataloss, i decided the samsung spinpoints had the best rating for reliability.

coorect me if i'm way off here, but from the way it was described to me, the internet radio server simply streams a single stream of music out to whoever happens to log on to the website, so there isn't a whole bunch of different streams running at once. i'm thinking that means that even though the spinpoints are only 3gb sata that they will have more than enough throughput for that environment.

[mDust]

coorect me if i'm way off here, but from the way it was described to me, the internet radio server simply streams a single stream of music out to whoever happens to log on to the website, so there isn't a whole bunch of different streams running at once. i'm thinking that means that even though the spinpoints are only 3gb sata that they will have more than enough throughput for that environment.

I'm sure a single HDD could handle dozens of streams if necessary. The disk loads the songs in to RAM much faster than they can play. Don't even worry about it.

[x88x]

i'm thinking that means that even though the spinpoints are only 3gb sata that they will have more than enough throughput for that environment.
No current platter HDD can saturate even 3Gbps SATA anyway, so that won't be a concern.

[xr4man]

this has been all very good info and i thank you all very much.

however, i just learned yesterday that this is not actually the server running the internet radio station. it is just going to be a file repository and storage. so i think it will only need a single 2T drive and an external drive for back ups. it won't be turned on unless adding files to the repository or uploading new music to the server.

just a little disappointing because i was wanting to actually build a raided machine.

hmm, maybe i will anyway if it's cheaper to raid some 1T drives than to go with a 2T drive.

stay tuned for a worklog on it in july sometime.

[x88x]

OOC, do you have any particular reason to use an external drive for backups? Setting up dual 2TB drives in a RAID 1 will offer better performance and would, imo, be the better option barring some specific reason to use an external.

[xr4man]

only because he already has an external drive with all his files on it.

after looking at some pricing, it looks like 3 1T drives in raid 5 will actually be cheaper than 1 2T caviar black drive. so i may still go the raid route anyway.