To SCSI or not to SCSI, that is the question...

How important do you think it is to have SCSI hard drives for web hosting? How important is it to have RAID? Is RAID 1 the best for web hosting?

Should you use SCSI drives?

Simple answer - yes!

Complex answer - it depends....

Many people will tell you that IDE drives are fine for normal, virtual hosting, however SCSI performs better under heavy loads.

It really does depend on what kind of sites you are planning to host, but SCSI drives are so cheap now, I'd just spend the couple of extra bucks and go with SCSI. And as long as you're spending the money on a SCSI card, you might as well make it a raid card and slap an extra drive in there (mirrored, of course).

I'd say go Scsi raid (mirrored). You can even make it a nice selling point. Something like "We only use u/160 SCSI RAID-1 hard drives".

Anyways, I think it's worth it! :D

Plan to host 50-100 sites? NO

Plan to host 100+ sites? Yes

Now those are the kind of answers I like to hear. Simple and straight forward.

aloha
you plan to host sites go scsi many reasons
MTBF, Latency, true multi tasking etc...
you can not put a number of sites on and say this is when you go scsi
I run one site 5million unique a month full database driven on coldfusion you would say I can run 50 of these on ide
????

basically for the few bucks more go scsi then you will not have to worry once you expand

Soon this thread will be SCSI or FC-AL?

How important is lack of downtime for you? Hot-swappable is probably another quesiton you should be asking.

How many 9's do you want to reach?

You can go as reliable as the sun (pun intended), but do you need it?

RAID-1 for hosting is fine, any higher a flavour of RAID is getting into just using a buzzword for the sake of using a buzzword. Many databases and applications will actually get far less performance from RAID-5 than RAID-1.

How many 9's do you want to reach?

What does this mean?

What is the difference between RAID and Hot-swappable?

99.999% (5-9's) = 5 minutes of downtime/year
99.99% = (4-9's)30ish hours (lost chart) of downtime/year, etc...

Remember, those numbers are on the actual server itself, where most downtime will result. 100% uptime SLA's are almost always exclusive to the Network (where very little downtime actually occurs these days).

Hot Swap allows you to pull out a downed drive, and replace it with a new one on the fly, without powering down the server. Not always the case with all servers, SCSI/RAID or not.

RAID will allow the new disk to populate with the data it needs.

Originally posted by Synergy
Plan to host 50-100 sites? NO

Plan to host 100+ sites? Yes

Those numbers are meaningless ... I have a P3/850 with 2GB of memory with only 4 sites hosted on it, 2 sites of which are running a heavy forum on VB. Getting about 90000 page views and about 600-700000 hits daily. Only have one IDE drive (7200rpm), not doing too great with too many activities (loading html pages, querrying/writing/reading mysql dbs, writing apache logs, mysql logs, etc) and IDE does indeed become a bottleneck right now ... Adding a second IDE and separate mysql dbs from /home might definitely help reduce the bottleneck, but I am currently building servers with 10k SCSI and I do think/expect this should make a difference ...

cheers,
:beer:

Meaningless? Your customers are not asking for Service Level Agreements? If you don't supply a realistic SLA, you'll be paying more in credits than you should be. Over promising on an SLA can seriously impact your business.

Hardware should get the bulk of the consideration when determining how many 9's you are going to offere in your SLA. Disk failures account for almost half of hardware failures in today's hosting environments, and therefore should get as much attention as all the other components combined.

Sure you can assume that people will fall for the 100% network uptime guarantee, but how many customers are really that uneducated these days? More will laugh at that ploy and steer clear.

Anyway, go SCSI, RAID, mirror, whatever. Just don't use a single point of failure on a cheap disk.

Just noticed your quote, sorry about that. I don't feel much like deleting, so slam away ;)

read, think, than talk!

cheers,
:beer:

Got a related question - If I'm going to be doing weekly/daily backups, is mirroring a big issue?

Also, if I RAID 0 the drives, isn't the end result at least as fast as a regular SCSI drive?

You always want to have some sort of mirror. Also, I strongly oppose using a RAID 0 system, as if you lose one hard drive in the RAID, you have no way to recover the data. The RAID 0 basically allows multiple drives to function as one.

If you are going to have 3 or more hard drives in your system, I'd recommend using a RAID 5 system. You don't get all the space offered by the drives, but this givesyou the benefit of backup. If one out of the three drives fails, you still have data. If you have two or more drives go out, you're still in trouble, but the odds of that happening are very slim. I've seen it happen before, but it is very rare. That's also why you keep tape backups.

If you want to use a 2-drive system, RAID 1 is the best, like others have said.

Tape backups come in where the hard drives fail. In my opinion, the real reason for keeping a tape backup is in the rare event that a multiple hard drive failure does occur, you've still got data. However, using this as your only method of backup is not preferred because of the customer data loss caused by nightly backups (nice to have all of your new work disappear!). On top of that, you may want to rotate your tapes periodically and keep one tape with data at least a week old. This way, if someone hacks into your system and you realize it a few days later, not all is lost. You've still got something to restore from.

SCSI, in my opinion, is the only way to host more than a few dozen customers. I've actually had IDE drives go out on my personal computer (actually, I replaced it before it went out and got a new one of a different brand), and you'll be spending a lot of time formatting and installing SCSI drives (RAID configurations can take several hours to format), and unless you want to buy expensive hard drives and a SCSI card for another computer to do the formatting on, you probably want to just stick with the SCSI and RAID to begin with.

By the way, you don't get away with setting up a server with under 512 megs of RAM, even with only a few dozen clients.

To sum it up, RAID 1 for 2 drives, RAID 5 for more than 2 drives, SCSI drives (unless you have time to format them later).

Another good idea is, if you think you'll outgrow your configuration and upgrade hard drives, then order the server with more than you'll need. If you have a RAID 1 configuration and want to get another hard drive, surprise! You've got to spend several hours and reformat them all (gotta love tape backups!).

Anyway, I hope I've shed some light on some other issues concerning a dedicated server, and best of luck to you.