I am bldg. a new machine w/:
1 gig DDR
-I'm considering going w/ 3-WD1000JB's w/ Promise ATA controller (striped in RAID 5). Does this scheme sound o.k.(/any objections?)? Can i get by w/ just 3 drives on RAID 5 or do i need more?? Does the 8mb buffer on these WD-JB series make a big difference or should i go w/ something cheeper (maybe slighly smaller)???
Thanks in advance for any insight!!
So obviously you need at least 3. Adding additional drives will increase performance. The drives you are looking at are great if you want to spend the $$. This setup wont be cheap but I guess you know that already since you have picked the equip already =)
Thanks for all the input! Hey, FatB - will I have a hard time installing a dual-boot XP/Linux OS on this array? I'm wondering if by making such a large array - I'm shooting not myself in the foot. Thanks again!
It would be very smart and not all that slow!! In RAID5 if one disk crashes you can replace it and rebuild the array, so you dont lose your OS and all its settings/drivers! That alone is a good reason to ise RAID5, but speed is another. RAID5 is NOT slow at all. Reading in fact is blazing fast as it reads from multiple drives. Writing is not nearly as fast, but if you have a quality RAID card with a good CPU and cache RAM it will do the calcs quickly and write the data to disks. The speed is not nearly that of the fast read but still faster then a single drive by far.
For the most part yes. It depends alot on file size however. Working with large files will allow you to see the power of lots of drives. For smaller files it does not matter and in some rare cases may be slower if you have too many drives. This is also where the "stripe size" plays a big role. A 4 drive RAID 5 array is pretty common and should give you great performance. If you are into data reliability (which it seems you are if your gonna run RAID5) you should have a "hot spare" if your controller supports it. This drive wont be used at all, until a drive fails then the array would be automatically rebuilt using the hot spare.
I run a machine with RAID 5 as well =) It is not as fast as my stripped set, esp when writing (both use 4 drives) but still very fast. I have all important data on that machine or the mirrored set I have on my workstation.....
In RAID5 if one disk crashes you can replace it and rebuild the array, so you dont lose your OS and all its settings/drivers!
Use software RAID 1 if you are sooooo concerned about the remote possibility of loosing your OS and save $500 on a RAID5 card and a 3rd HD. In any event, I am always glad to know that I have made parity calculations for my paging file and all the temporary internet files and other crap which windows creates.
Reading in fact is blazing fast as it reads from multiple drives.
Reading in RAID5 is somewhat faster than one drive, but about twice as slow as RAID0. Writing in RAID5 is lurvely compared to RAID0.
Really IMHO RAID5 is useful only for fileservers using many harddisks (hence a realistic chance of failure - unless using IBM ) which need constant data backup. Oh RAID5 is also good for people with too much money who want to say they have RAID5 in their PC. Damm, I must just be jealous
Hahaha. I do run RAID5 myself, and its even IBM (although I have seen more bad parts from IBM lately then any other vendor, starting to piss me off) and it is very fast. I DO have RAID0 on antoher machine and it does go much faster then RAID5, but RAID5 is far faster then RAID1 as there is no stripes. Some people are too lazy to do backups yet have critial data on the bootup disk like mail or have a system that cant be down due to hard disk failure. RAID5 has many uses, although I do not in any way claim that it is the best for all situations.