DIY Disk Array?
This is a newbie question as I'm about to take the plunge and try my hand at building a DTV Computer. One thing I'd like to create is a Disk Array of removeable drives. Some video projects take longer to edit and I'd like the flexibility of removeable drives to allow for short term project turnaround and longterm project work.
Any recommendations would be appreciated.
One thing I would like to suggest is do not use sata drives. Sure they have smaller cables and allow more airflow, but they do have some design issues. First, the sata connections if you have never experienced them before are unbelivably flimsy, I've had to severely tape my down to keep them from wiggling loose. Before the tape, I've had just a car ride loosen them enough to where they wont work. I've read of people reporting that just the bass from their subwoofer loosened them.
Another issue, or at leat on the DIYII overbudget project, is that when you initially install WinXP (not sure about other OS's) it WILL NOT see the sata drives unless windows is already installed on there. I initially bout 4 sata drives, but had to get a 5th parrallel IDE drive just so windows would see it to install its OS.
From what I've read, the next generation drives, SATAII, will have latching plugs that should fix the cable issue. My DIYII unit works great, now that I have everything worked out, I just wish these issues would have been mentioned in the article, or at least responded to in the forums when I mentioned them, it would have saved a lot of grey hairs.
Also I dont quite see why you are aiming to go with removable disk array, drives today are so cheap, for around $300, you can store about 90 hours of just raw video, which is about 240 hours of mpeg2 video.
Re: the SATA drives that wiggle loose on their own... I use a hot glue gun and leave a small dot of glue, so the cable could not come loose from it's connecdtion... thus less tech support needed when shipping the computer around. With a little bit of effort the glue 'dot' comes off clean.
Since I have not used a SATA drive yet... do you think you could place a dot of hot glue to keep the SATA cable from coming loose?
I also say.. why a disk array? Are you looking for a hot swappable RAIDed drives? or can you live with an external firewire drive for a cheaper price?
I use 2 large internal RAIDed drives and 1 external HD case with multi drives for clearing my RAID drives of old projects. Plus the old projects will work off the external drive just incase I need to do a simple update edit. OR copy everything back for a top-to-bottom re-edit.
my 2 cents
Thanks to all for the observations, advice, first hand experience, etc.
I'm interested in an array probably because it's been what I've become accustomed to having worked on proprietary editing systems for years where you work on a lot of projects and each project workflow is not the same. I've worked on projects that took 3 years to complete and dealt with a lot of raw footage, test edits, client revisions etc. And so having a RAID Array with hot swappable drives made things a bit easier to manage.
I've considered external drives (i.e. firewire, etc.) and have tested a couple out with good results. However; I've thought about SCSI configured drives as that's what I've been accustomed to and while the other drives are quite good, everything I've read indicates SCSI for faster data needs. The drives in my older arrays were Seagates for SCSI and they were/are tough. I only had one drive failure since 1994 and it was still under it's original 7 year warranty. (And I used these drives a lot!)
While I can load a tower up with drives, there's the added issues of more heat and having a separate enclosure can assist with airflow and cooling.
I'm an old analog dog who learned NLE back when the image was the size of a fuzzy postage stamp at 15fps. But I would like to give a DIY a go and see what configuration I can come up with on my own.
Again, thanks for everyone's input.
Check out Macgurus.com to get some information on rolling your own RAID system.
As the names implies, it's intended for MAC users, but the Burly Boxes and drives are compatable with PC. The SATA or SCSI controller (Adaptec) you'll have to figure out.
I haven't been able to find a similar site for PC users.
I hate to disagree... but we have been using SATA drives as boot drives since they've been available. There is just a certain way that you need to install the OS, and only on certain chipsets. Someone just needs to show you how to do it, or you can even just dig through your motherboard manual. It's in there. SATA is just as compatible as PATA.
As far as the connections coming loose - boy what a headache. The issue is that they are made to be hot-swappable, hence the 'quick-connect' sort of interface. We usually try and overcome this by positioning the cables in a way that there is a slight pressure on the connector at all times (We can't go gluing drives in our machines, unfortunately... in my own, maybe, but not customers').
It may just have been the mobo (Asus P5AD2 Premium), but it actually did say in the manual that it would not recognize the drives unless the OS was already on there, I tried the RAID connections on the board and the regular SATA plugs. The saw them fine, and I was able to setup the raid in the CMOS as well, but when you try to install winXP on them, the windows install did not recognize any drives attached. I tried every imaginable option in the CMOS. The PATA drive installed first attempt. Hopefully it will be fixed in a future BIOS update. If you have experience with this mobo and know how to do this, please forward me the info...it would be nice to have in the future
Yeah... that is a board that we have used recently quite a few times, and always with all SATA drives. (Haven't used PATA since SATA came out)
Any modern chipset/BIOS is made now so that SATA drives can be recognized as native IDE. I have a feeling that if you were having any problems installing the OS, it was because you are using RAID as well on the same controller (southbridge). If I remember correctly, that board has 4 ports off of the ICH7 southbridge, and another port that is running off of another controller, linked with PATA RAID ports (really wierd configuration as I remember). If you are running RAID on the same controller as the boot drive is plugged into, you need to create a driver diskette (drivers are located on the CD - there are a slew of them, and it's easy to choose the wrong ones). Then, Windows is installing you follow the prompts to press F6 and install a third party SCSI device.
These are obviously extremely shortened versions of helpful directions, I understand, but the point is that it definitely is workable and normal and completely within the designed specifications of modern motherboards. More explicit instructions are in the manual.
Thanks for the info, if for some reason my current config crashes, I'll mess around with it some more. I did not use a driver disk on install, so yeah that may have been the difference. I have never attempted to use a separate drivers disk on Windows initial install, do you use the same drivers that you would once windows is installed?
It's the same drivers, yes. Sometimes board manufacturers are including actual executable files on the CD that creates the driver disk for you... which is actually pretty helpful because the disk has to be made correctly and that's just another thing to mess up.