Please help with RAID questions

Teekster

Senior member
Dec 28, 2000
253
0
0
I am charged with the task of building a box for a database server. I am wondering if anyone has thoughts on RAID 0+1 vs. RAID 5, especially software RAID 0+1 vs. hardware RAID 5.

This will be based on a Tyan Tiger MP dual Athlon system
 

IgoByte

Diamond Member
Jan 23, 2001
4,765
0
76
I wouldn't go software in any case.

I can't clearly remember at this moment what exactly RAID 5 accomplishes, but if you're building a server, you need redundancy and hence RAID 1. I'm not sure what you're planning on, but I'd go with four or eight very large drives in RAID 0+1. This would mean that you get the capacity of half of the drives you use and you get some speed improvement over just RAID 1.

I'm sure someone here can shine more light on this issue than I just did...
 

chew

Junior Member
Sep 1, 2001
13
0
0
Although RAID 0+1 would be faster if you were after high throughput of large amounts of data, such as for video or audio work, RAID 5 I believe is comparable (or possibly better?) when you only need to fulfil high amounts of i/o requests such as a database server creates.
So if you are at all concerned about costs, the RAID 5 would be better since you only need one extra drive for redundancy as compared to 0+1 which requires doubling the number.
 

JW

Member
Oct 11, 1999
118
1
81
Sorry if this will seem Oracle-centric. I'm just not familiar with the terminology/processes that other systems use.

Anyway, generally speaking:

RAID 1 is excellent for online and archived redo logs (LGWR and ARCH processes). Sequential access is the key here. Typically, online logs are kept in multiple groups/sets, so spread these across multiple RAID 1 volumes. Archived logs on a separate RAID 1.

For datafiles, consider: RAID 1+0 is better for write-intensive software, so this is good for OLTP databases. RAID 5 is better for read-intensive, so this is a fit for OLAP/data mart/data warehouse databases.

-jw
 

Teekster

Senior member
Dec 28, 2000
253
0
0
The cost is a wash. I am specifically comparing a Promise FASTTRAK100 TX4 ($125) software RAID card with 4 WD 60 GB HDs (WD600BB) ($121 each) running RAID 0+1 vs. a Promise SUPERTRAK SX6000 ($260) and 3 WD 60 GB HDs.

The total is $609 for software 0+1 RAID and $623 for hardware RAID 5.

Which is the right solution? I'm trying to do this on a limited budget. The database will be running 4D software for a patient database for medical procedures. It will be accessed through a hospital intranet by as many as 7 users at once. The license we bought was for 7 users, but we may increase it as the need permits.
 

Nothinman

Elite Member
Sep 14, 2001
30,672
0
0
Software RAID isn't too bad at levels 0 and 1 because there's no real calculations going on, just another disk write, but Software RAID 5 can eat CPU cycles because it's gotta generate parity bits for every write. Also Linux software RAID has been known to be the same or better at RAID 0 or 1 with hardware setups, I have no idea how Windows software RAID runs and frankly I wouldn't trust it.

If the server is holding data that's worth anything to the company get them to pay for hardware RAID, preferably SCSI with hotswap drive bays. The price up front is higher but you'll get better performance (SCSI works a lot better with multiple drives than IDE), better reliability (MTBF is higher with SCSI drives) and hotswap means if one drive actually does fail there's no downtime to replace it. I would also go with a "big name" box like Compaq or Dell, mainly for support, you don't want to be buying replacement drives at CompUSA late one night because you don't have a support contract that brings the replacements to you.

The database will be running 4D software for a patient database for medical procedures. It will be accessed through a hospital intranet by as many as 7 users at once. The license we bought was for 7 users, but we may increase it as the need permits.

With only 7 users I don't think the database or drives will be too stressed in either situation, but like I said above I wouldn't put a homebrew box in a position that needs high availability, it may work fine for a long but time the one time it does break the sh!t hit's the fan and you don't have anyone else to blame (i.e. Compaq or Dell).
 

Woodie

Platinum Member
Mar 27, 2001
2,747
0
0
Limited budget, I understand, but production data, w/ a database belongs on a supportable box. Means hardware raid, since performance isn't a huge issue and cost is--raid 5. Hot-swappable just makes sense, I'm not even sure you can get non-hot swap (SCSI) drives anymore.

I *strongly* suggest one of the (Intel) "server" vendors (Compaq, IBM or HP).

--Woodie
 

miguel

Senior member
Nov 2, 2001
621
0
0
A mix is better, I think: Raid 1 for the redo logs and Raid 5 for the database.
 

Woodie

Platinum Member
Mar 27, 2001
2,747
0
0
Combination is not necessarily better: It increases the complexity of the server, and makes recovery more difficult.

For the performance difference for a 7 user application, I don't think it's a good trade-off. I've been in the recovery situation, and it's just easier if the only thing you do is call Compaq (or whomever) for a replacement drive, and plug it in when it arrives. No: Which partition is the drive in, if the Raid1, then do this, if the Raid5, then do that.
No thanks!

--Woodie
 
sale-70-410-exam    | Exam-200-125-pdf    | we-sale-70-410-exam    | hot-sale-70-410-exam    | Latest-exam-700-603-Dumps    | Dumps-98-363-exams-date    | Certs-200-125-date    | Dumps-300-075-exams-date    | hot-sale-book-C8010-726-book    | Hot-Sale-200-310-Exam    | Exam-Description-200-310-dumps?    | hot-sale-book-200-125-book    | Latest-Updated-300-209-Exam    | Dumps-210-260-exams-date    | Download-200-125-Exam-PDF    | Exam-Description-300-101-dumps    | Certs-300-101-date    | Hot-Sale-300-075-Exam    | Latest-exam-200-125-Dumps    | Exam-Description-200-125-dumps    | Latest-Updated-300-075-Exam    | hot-sale-book-210-260-book    | Dumps-200-901-exams-date    | Certs-200-901-date    | Latest-exam-1Z0-062-Dumps    | Hot-Sale-1Z0-062-Exam    | Certs-CSSLP-date    | 100%-Pass-70-383-Exams    | Latest-JN0-360-real-exam-questions    | 100%-Pass-4A0-100-Real-Exam-Questions    | Dumps-300-135-exams-date    | Passed-200-105-Tech-Exams    | Latest-Updated-200-310-Exam    | Download-300-070-Exam-PDF    | Hot-Sale-JN0-360-Exam    | 100%-Pass-JN0-360-Exams    | 100%-Pass-JN0-360-Real-Exam-Questions    | Dumps-JN0-360-exams-date    | Exam-Description-1Z0-876-dumps    | Latest-exam-1Z0-876-Dumps    | Dumps-HPE0-Y53-exams-date    | 2017-Latest-HPE0-Y53-Exam    | 100%-Pass-HPE0-Y53-Real-Exam-Questions    | Pass-4A0-100-Exam    | Latest-4A0-100-Questions    | Dumps-98-365-exams-date    | 2017-Latest-98-365-Exam    | 100%-Pass-VCS-254-Exams    | 2017-Latest-VCS-273-Exam    | Dumps-200-355-exams-date    | 2017-Latest-300-320-Exam    | Pass-300-101-Exam    | 100%-Pass-300-115-Exams    |
http://www.portvapes.co.uk/    | http://www.portvapes.co.uk/    |