binar said:
In regards to boot time.... It is not going to take any longer.. During boot, the system is reading. So the system is reading the Data blocks. The involvement of the parity data is during the write operation of Data blocks. The controller writes the Data blocks and then it creates two Parity data (backup info of the data blocks)... But when reading the data, the controller should only be reading the data blocks... So, is the system is just reading, the total time for a boot up shouldnt be any longer.
Write times.... technically, the write times of a raid-5 is a tad slower than 10... raid-6 write times are identical to raid-5. Thats pretty amazing especially when raid-6 has to create two parity data for each write operation.
Losing the whole array during rebuild.... well..... in a raid-5, if you loose a drive, replace the drive, and the array initiates a rebuild.... it is true that if you loose another drive during this rebuild process... you will be up the creek without a paddle. Array goes pooof... BUT, with raid-6.... you loose the first drive, replace the drive, the array initiates a rebuild.... if you so by chance loose a second drive during the rebuild....ummm dont panic... the array is still good. because in a raid-6, you are able to loose two drive and still be ok.... it's the loss of the third drive that will get you. So bottom line with raid-6 is that you dont wait till you loose 2 drives before you decide to start replacing drives..
G.G.
Thanks for the excellent links. I have looked at all of them and have to say that RAID is a subject that goes very deep in complexity. THe coolest link is the calculator. I tried it out and got results close to what you got.
I have researched RAID technology enough and ...................
1. A negative is it takes longer to bootup compared to RAID 10. I read it is because it's got to go through a two parity check. If it's an extra 2 minutes of bootup time I can live with that.
4. A negative for RAID 6 is slower Writer times. Read times I was told were the same between RAID 6 and RAID 10.
6. A negative I was told is how RAID 6 has the potential of losing your entire data if during a 12 hour long hard drive recovery phase an additional hard drive fails.
Thanks for the excellent links. I have looked at all of them and have to say that RAID is a subject that goes very deep in complexity. THe coolest link is the calculator. I tried it out and got results close to what you got.
I have researched RAID technology enough and ...................
1. A negative is it takes longer to bootup compared to RAID 10. I read it is because it's got to go through a two parity check. If it's an extra 2 minutes of bootup time I can live with that.
4. A negative for RAID 6 is slower Writer times. Read times I was told were the same between RAID 6 and RAID 10.
6. A negative I was told is how RAID 6 has the potential of losing your entire data if during a 12 hour long hard drive recovery phase an additional hard drive fails.
In regards to boot time.... It is not going to take any longer.. During boot, the system is reading. So the system is reading the Data blocks. The involvement of the parity data is during the write operation of Data blocks. The controller writes the Data blocks and then it creates two Parity data (backup info of the data blocks)... But when reading the data, the controller should only be reading the data blocks... So, is the system is just reading, the total time for a boot up shouldnt be any longer.
Write times.... technically, the write times of a raid-5 is a tad slower than 10... raid-6 write times are identical to raid-5. Thats pretty amazing especially when raid-6 has to create two parity data for each write operation.
Losing the whole array during rebuild.... well..... in a raid-5, if you loose a drive, replace the drive, and the array initiates a rebuild.... it is true that if you loose another drive during this rebuild process... you will be up the creek without a paddle. Array goes pooof... BUT, with raid-6.... you loose the first drive, replace the drive, the array initiates a rebuild.... if you so by chance loose a second drive during the rebuild....ummm dont panic... the array is still good. because in a raid-6, you are able to loose two drive and still be ok.... it's the loss of the third drive that will get you. So bottom line with raid-6 is that you dont wait till you loose 2 drives before you decide to start replacing drives..