Another ?should I RAID?" post

[IsDanReally]

I?ve read all the should I RAID posts, but none of them seem to cater to my situation, so?

In a month or two I?ll be building a new system for myself. It will be replacing not having a desktop for the last 6 years and an aging fileserver. Currently the file server is in a software RAID 5 and is fine because it can saturate 100Mb Ethernet no problem. The new system will be used by me to play games (older games, lots of new game demos, and any new games I take a liking to), some video editing and DVD creation, as well as a media server for my Xbox 360. Right now, I have about 300 GB of stuff I?d prefer not to lose, and 100 GB of stuff that is very important not to lose.

I was thinking of getting 4 320GB drives, using one for the boot, and making a RAID with the other 3. I lot the disadvantages to this setup I thought of are: cannot put swap file, scratch space for Adobe products, temporary space, etc on other drives (because it might be slower)?and any backups would then take 33% more space because of RAID parity info.

Other possibilities I?d like opinions on are?

Only buy 3 drives for now, use 1 for media storage, 1 for OS, one for, and 1 for backup. This has the advantage of costing less of course, and more space can be added later, and the drive would be bigger, faster, cheaper, and newer. Disadvantage is that backups would become more important to keep up on.

1 of the drives used as a mirror and the other 2 separate. This seems nice because of being able to mirror data, but bad because the redundant disk would be smaller. Also, seeing as how things would still need to be backed up, could be potentially wasteful.

Any input/suggestions/other ideas you might have, I?d love to hear.

 

[GrammatonJP]

2 750gb seagate in raid 1 for data.
1 fast drive for boot.

is speed a requirement ?

 

[alpha88]

I don't recommend raid for backup purposes - only reliablity (can still run when one goes).

I think you're still at nearly just as much risk of losing your data when you use raid1 or 5 as compared to a single disk.

I've had many hard disks fail, but never such that I couldn't get the data off before it was completely dead. When you're running raid, you are still at risk to viruses, bad power surges, user error, fires.

 

[IsDanReally]

Originally posted by: alpha88
I don't recommend raid for backup purposes - only reliablity (can still run when one goes).

I think you're still at nearly just as much risk of losing your data when you use raid1 or 5 as compared to a single disk.

I've had many hard disks fail, but never such that I couldn't get the data off before it was completely dead. When you're running raid, you are still at risk to viruses, bad power surges, user error, fires.

Which is why I would still backup I personally have had a few drives fail that could not be completely recovered. I've had drives that work fine one day, and within 12 hours no longer are detected by Windows. In that case it was part of a RAID, so made recovery very easy.

I definately agree that RAID isn't a backup for important data (but good enough for some). That point was reinforced when I discovered a flaw in Windows Media player 10 where deleting "unknown album" by one artist deletes it for all of them

So, are you then recommending not to RAID any of the drives and just use good backup software?

 

[IsDanReally]

Originally posted by: GrammatonJP
2 750gb seagate in raid 1 for data.
1 fast drive for boot.

is speed a requirement ?

While I like that option, the 750gb drive and even the 500gb are at a price premium that is not worthwhile to me. Speed is only a requirement in that I don't want things to be slow. I also wouldn't want an array to be slower than a single drive (is this the case with SATA drives that aren't connected to the PCI bus, when used in a software RAID 5).

 

[tcsenter]

RAID only makes sense for improving I/O performance and/or protecting data that is in a continuous or very frequent state of change. There is a 'Wow, I am running RAID' cool factor that doesn't really translate into any practical benefit (i.e. subjective). RAID is added complexity, IMO complexity should not be added without good cause or effect (or you're just asking for added risk with no benefit).

Straight-forward file servers aren't necessarily a good candidate for the protective benefits of RAID, depending on how frequently the data changes. The data on many file servers remains relatively stable between infrequent uploads (e.g. weekly), but a heavily utilized file server should benefit from the improved I/O performance of a properly tuned RAID.

I haven't seen any tests showing a substantial benefit in gaming performance. Measurable benefit, yes, but not substantial enough to translate into real increases in frame rates. You can get more substantial increases in gaming performance by upgrading the processor or video card.

With today's AV-ready SATA II hard drives (16MB cache) and controllers, I don't see hobbyist or prosumer level video editing/encoding benefitting much from RAID.

 

[alpha88]

I recommend it for performance, or if you don't want downtime. The hard drive that was dead within 12 hours probably could have been resurrected temporarily be freezing it or by using GetDataBackNTFS.

I kind of do a 'manual' raid 1. I weekly mirror all my important data to a second hard disc (in a seperate computer, but that isn't that relevant). I also make an image (and burn to DVD) of my OS partition whenever I install new programs (not games).

 

[IsDanReally]

Those are both good points. The bulk of the data I'm concerned about rarely changes. From my current server, I know RAID does add complexity (meaning in checking the event log, disk management for errors).

I'm not too concerned with downtime, so long as I don't have to spend too much time making sure data is safe...using tons of DVDs, etc. I like the idea of on image for the OS partition. Do you use Acronis, or something else?

Also, for a worst case question...would have OS, swap, scratch, and source DV files, all on 1 drive be unusable for video editing? How about split onto 2 physical drives?

I'm appreciating these answers, as I am always for making systems simpler to use.

 

[alpha88]

I haven't done any Video editing, so take this with a grain of salt...

I use a Raptor for my OS + Games. My swap file is there too, but it doesn't matter with 2 gigs of ram.

I use a SATA-II drive for my media (and IDE on a seperate computer for backups).

If I were to start editing video, I think I'd make a scratch drive consisting of RAID 0 SATA II drives. (I've seen 300Gb Seagates for $100), so I think I'd use two of those.

 

[bob4432]

my current setup is simple and works. you would just need to change hdd sizes to get what you need.

my current home server - 1 30GB os/apache/mysql hdd, 1 60GB hdd that holds the sites and ftp accessed files, 1 120GB image hdd where all images created to acronis go

my machine - 1 36GB os/app/game hdd, 1 80GB data hdd

obviously all the hdd are not even near full but what i do is have acronis backup all the other hdds images to the 120GB throughout the week from the server machine and my machine. this is all done through scheduling in aconis so at worst i would lose 1 wks worth of data. the server machine is hooked up to a ups with a decent psu in it. the system work very well and needs little input from me, which is nice because sometimes i may forget

then every week or two i plug in my laptop into a cat5 cable and use acronis to image its hdd to the server

 

[ss284]

You have a ton of requirements, and I think it would be best if you used one drive for boot, one for swap, and another 3 for raid 5 data storage. Assuming you use 320 gb drives, which are about $120 a piece right now, youll end up with a good amount of storage (640gb 3 drive raid 5), as well as a boot drive and another drive for editing and general usage.

I would advise you to at least find a dedicated controller instead of software raid 5.

 

[EatSpam]

Get 4 320gb drives plus an Areca 1210 PCIe RAID card. Run all 4 drives in RAID 5. This is a hardware card and the RAID 5 speeds are excellent.

 

[IsDanReally]

Originally posted by: EatSpam
Get 4 320gb drives plus an Areca 1210 PCIe RAID card. Run all 4 drives in RAID 5. This is a hardware card and the RAID 5 speeds are excellent.

I like that idea, but unfortunately it's a bit wasteful to me and pushes me over the amount I wanted to spend. Certainly something I will think more about though. As I really liked the hardware RAID I built into a media server I then turned around and sold.

 

[IsDanReally]

Originally posted by: ss284
You have a ton of requirements, and I think it would be best if you used one drive for boot, one for swap, and another 3 for raid 5 data storage. Assuming you use 320 gb drives, which are about $120 a piece right now, youll end up with a good amount of storage (640gb 3 drive raid 5), as well as a boot drive and another drive for editing and general usage.

I would advise you to at least find a dedicated controller instead of software raid 5.

Then I would have 5 drives and really I'm not sure if I would need that much space. My requirements are very flexible too, because they are often just my wants. It seems like right now, considering what every one has said, that 3 seperate drives might be best, and then just utilize them in ways that work good for the specific need (ie, backup drive could also be scratch drive, etc).

I'll have to think about it though for a bit and see how I feel. Though definately a good idea to keep RAID 5 as a hardware only option.

 

[GrammatonJP]

I'm pretty sure software raid 5 eats a lot of cpu power, especially when 1 drive fails... the cost of calcuation will be slow enough that you wish you had gotten raid 1 instead of 5.

Unless its hardware raid 5, you're not gaining much in i/o, you're giving up cpu power for the parity calculation

http://tweakers.net/reviews/557/19 - comparison of hardware and "soft" raid.. cpu usage is 3x more, but raid 1/0 is far less.

 

[SnoMunke]

Software RAID-5 does NOT use alot of CPU power...I have done software RAID-5 and watched the CPU utilization and it never got above 10% (usually around 5%).

 

[SnoMunke]

Originally posted by: tcsenter
RAID only makes sense for improving I/O performance and/or protecting data that is in a continuous or very frequent state of change. There is a 'Wow, I am running RAID' cool factor that doesn't really translate into any practical benefit (i.e. subjective). RAID is added complexity, IMO complexity should not be added without good cause or effect (or you're just asking for added risk with no benefit).

Straight-forward file servers aren't necessarily a good candidate for the protective benefits of RAID, depending on how frequently the data changes. The data on many file servers remains relatively stable between infrequent uploads (e.g. weekly), but a heavily utilized file server should benefit from the improved I/O performance of a properly tuned RAID.

I haven't seen any tests showing a substantial benefit in gaming performance. Measurable benefit, yes, but not substantial enough to translate into real increases in frame rates. You can get more substantial increases in gaming performance by upgrading the processor or video card.

With today's AV-ready SATA II hard drives (16MB cache) and controllers, I don't see hobbyist or prosumer level video editing/encoding benefitting much from RAID.

Are you saying the 1.5TB RAID-5 file server housing my DVD ISO images is not a "good candidate for the protective benefits of RAID"? You want to give me a better solution?

 

[alpha88]

Yes. JBOD (Just a bunch of disks) (only 2 x 750gb drives?)

You save 400 bucks, with which you can buy a tape backup drive.

You'll loose very little performance, and you'll get way more reliablity.

 

[IsDanReally]

For $400, it seems like you can only get a 104GB (40GB uncompressed) tape drive. Backing up 1.5TB that way would take a long time. Even my potential array of 640GB wouldn't be Granted it would be easier than backing up to DVD, but for material that isn't extremely critical it hardly seems worth the time. Remember I said only a small part, 30 - 40 gigs, was deemed critical. Fitting my wants, it seems like a slower software RAID 5, a boot drive, and another work drive might be the way to go.

 

[SnoMunke]

Originally posted by: alpha88

You'll loose very little performance, and you'll get way more reliablity.

You flat-out do NOT know what you are talking about. Using this tape backup as an example, it will take 3 hours to backup 40GB of data...and I have 900+GB of data to backup...22 tapes times 3 hours = 66 hours.

Now seeing tha I only have time to touch my computer for about 4 hours a day during the week that means I can probably do a start/finish/start next backup per day...so, we are looking at 10 days to do a single full data backup?

And then of course we can't forget the time to restore data from tape back to new spinning HDDs if original HDDs fail...I wonder how many days that will take?

Congratulations! You have now given me the dumbest advice I have ever gotten in this forum.

 

[tcsenter]

Are you saying the 1.5TB RAID-5 file server housing my DVD ISO images is not a "good candidate for the protective benefits of RAID"?

Do your ISO images change regularly? I suspect they don't change at all and each ISO is static. Therefore your RAID'ed ISO storage is no more reliable or protective than storing the original (i.e. pressed) DVD in a safe location, burning each ISO to archive quality recordable DVD, or just copying your ISOs to enterprise class hard drives as a backup (vs. desktop commodity class).

You want to give me a better solution?

A better solution for serving your ISO images or protecting them from loss?

 

[alpha88]

A RAID-5 array full of DVD ISOS isn't a valuable backup. You're one lightning strike, defective PSU, etc away from loosing all your data. Important data needs to be on seperate systems (and if super critical, in a different location)

I wasn't suggesting that you update a backup tape, since your images shouldn't change. Just put some images on the tape and put the tape in a safe place, hopefully never using it again. (Or store them on two computers, or burn to new DVDs and store them safely)