Portal Home > Knowledgebase > Articles Database > Raid question
Raid question
| Posted by bbrog, 01-11-2011, 06:10 PM |
| Hey, I have a question about raid5 and raid10
1.)How many drives can fail on a raid5 and on a raid10?
2.)If one hard drive dies and we replace it will the data automatically get rebuilt on both raids? Is one raid fast and rebuilding data then the other?
3.)What are the read and write performances like on these 2 raids?
Please do let me know thanks!
|
| Posted by TheHostGenie, 01-11-2011, 06:51 PM |
| Wikipedia has a great article on this: http://en.wikipedia.org/wiki/RAID
|
| Posted by OLM | DavidG, 01-11-2011, 07:20 PM |
| 1) You can lose one drive from a RAID5 array without data loss. With RAID10 you can certainly lose one drive, and possibly two, depending on which drives fail.
With RAID6, you can certainly lose two drives without data loss, but it is recommended to use a high performance RAID controller with a larger number of drives, if you plan to use RAID6. For instance, an Adaptec 5805 with BBU (write cache enabled) along with 8 SATA or SAS drives works well with RAID6.
2) The behavior after replacing a failed drive could differ between controller manufacturers. With modern Adaptec controllers, the re-build process usually starts automatically once the failed drive is replaced, assuming that the new drive is large enough to be added into the array. That behavior should be the same between all RAID levels (RAID10, RAID5, RAID6, etc).
3) I would recommend viewing the Wikipedia article which TheHostGenie posted, for a detailed description of the performance differences between all of the various RAID levels.
|
| Posted by brentpresley, 01-11-2011, 07:22 PM |
| See my comment on your related question.
RAID 10 - GREAT for reads and writes
RAID 5 - GOOD for reads, HORRIBLE for writes.
The time to rebuild a RAID will depend upon 1) the speed of the drives and 2) the amount of data to be rebuilt. These times are longer on RAID 5 because the write speeds are that much slower.
As mentioned in my other post, don't try to do RAID 5 on software RAID.
|
Add to Favourites 
Print this Article
Also Read
wget save as? (Views: 682)
Shared Hosting
Shared Hosting
