Drew Wutka
DWUTKA at Marlow.com
Mon Jun 21 09:25:15 CDT 2010
Ok, a little fuzzy about your math here. First of all, a RAID 1+0 (RAID 10) is actually 2x used for x storage space. It's a striped mirror set, so you use up 2 drives for each mirror set, and then stripe those. Second, 1 gig drives...really? That's VERY small by today's standards! Hopefully you meant terabyte. How much space do you actually need? From what you are saying, it looks like you have 16 drives. (2 sets of 6 disk RAID 6, (which is 12 drives as you said), plus a 2 drive striped set, plus a 2 drive mirrored set). The way you SHOULD have this setup is with a 2 drive mirror, and a 14 drive RAID 1+0. That first mirrored set should be your operating system. Put NOTHING else on there. Then install everything else to the RAID 1+0. You said you had a budget for upgrading your machine. John, I'm serious, when reading and writing from a database, your absolute most limiting factor is going to be drive speed! So what kinda storage space do you need, and how big are your drives? (Again, I'm assuming your way off on the 1 gig part). I guess you could be getting very small solid state drives, but those aren't idea for a database either. If you went with fairly cheap drives (260 gigs are like $35 range, depending on the interface), for $560, you could have a 260 gig root drive for your OS, and then 1.8 terrabyte data drive. Drew -----Original Message----- From: accessd-bounces at databaseadvisors.com [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of jwcolby Sent: Sunday, June 20, 2010 7:46 AM To: Access Developers discussion and problem solving Subject: Re: [AccessD] Needs analysis Thanks Drew. When it comes to raid, my issue is money. Raid 10 requires 4x the drives for x storage. Raid6 requires x+2 drives for x storage. If you take an example... I have a 16 port coprocessor (TWELVE HUNDRED DOLLARS!). 4X storage means the most storage I can get on that is 4 gigs using 1 gig drives. X+2 means I could get 14 gigs theoretically. In fact I have two 4 gig arrays (12 drives) plus a 2 drive raid 0 plus a 2 drive raid 1. Yea, if I were made of money I would do things differently, but this is a one man shop here, not Microsoft (who can afford to throw money at it). John W. Colby www.ColbyConsulting.com Drew Wutka wrote: > Memory and processor can also go more and faster, but to throw my two > cents in, drop the RAID 6. > > http://en.wikipedia.org/wiki/Standard_RAID_levels > > http://en.wikipedia.org/wiki/Nested_RAID_levels > > RAID 0 gives you the best performance of any RAID. However, it has NO > redundancy, so if you lost one drive, you lose all your data. RAID 5 is > probably the worst for performance, and RAID 6 is a little better (well, > RAID 1 in some scenarios is worse..it has NO write advantage, and in > older implementations, RAID 1 doesn't let both drives read at the same > time, but most new RAID controllers do this, so RAID 1 , in a two drive > system would read at the same speed as a RAID 0 with 2 drives.) > > I personally recommend RAID 10 (or RAID 1+0). That is NOT RAID 0 +1 > (there is a difference, described in the second link. One is a mirrored > stripe, the other is a striped mirror. RAID 1 +0 gives you the absolute > best performance along with redundancy. And as you can see in the > second link, that's what is recommended for database systems, in fact, > it's what MS recommends for exchange servers. > > Drew > > > -----Original Message----- > From: accessd-bounces at databaseadvisors.com > [mailto:accessd-bounces at databaseadvisors.com] On Behalf Of jwcolby > Sent: Saturday, June 19, 2010 10:57 AM > To: Access Developers discussion and problem solving > Subject: [AccessD] Needs analysis > > I am about to upgrade my SQL server. Currently I run a quad core with > 16 gigs ram, using data on > raid6 arrays with a dedicated raid co-processor. I have an opportunity > to build a server that > better meets my needs but I need to discover what those needs are. > > As I have posted previously I process fairly substantial lists where > (for example) I will join a > table with 20 million names to a table with 65 million names on a sha > hash field and select by a > half dozen field criteria. Stuff like that. My databases are, > generally speaking, read-only. This > is not transaction stuff, but rather "data mining" kind of stuff. > > These queries can take a long time to run, tens of minutes or more. > What I would like to find out > is what is the bottleneck. If I increased my memory to 32 gigs would > that be enough? Would 64 gigs > be better or not be any better than 32 gigs? How much memory do these > queries want? If I increased > my cores to 8 or 16 would that be enough? How many threads would these > queries use? If I moved > some of the database onto SSDs would that help more than additional > memory? How much time / > resource is spent loading the data off of disks. > > I have absolutely no idea how to discover this kind of information. I > am going to have X dollars to > use to build a server, and of course X is never enough, so I need to > decide whether to spend more on > cores, memory or disks and in what combination. As an example I have > enough to buy either 24 cores > and 32 gigs of memory, or 16 cores and 64 gigs of ram, or 16 cores and > 32 gigs of ram and a bunch of > SSDs. > > I am pretty sure that regardless of what I do I will get a substantial > performance leap, however > maximizing that performance leap is still a good thing. > > Any help appreciated. BTW, I am NOT a DBA so if you give advice like > "look at the logs", please > give specific directions on how to do that. > -- AccessD mailing list AccessD at databaseadvisors.com http://databaseadvisors.com/mailman/listinfo/accessd Website: http://www.databaseadvisors.com The information contained in this transmission is intended only for the person or entity to which it is addressed and may contain II-VI Proprietary and/or II-VI Business Sensitive material. If you are not the intended recipient, please contact the sender immediately and destroy the material in its entirety, whether electronic or hard copy. 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