Linux raid 5 poor rebuilding performance?

[ugo1]

Hi,

I tried to build a raid 5 configuration with mdadm and 3 500GB disks. Building it msstat tell me that I need wait 618 minutes? It's that correct? I'm testing it on Jaunty and a core i7 920 processor

If 618 minutes possible? To me seem to long

Regards

Ugo

 

[sammynl]

Hi,

I tried to build a raid 5 configuration with mdadm and 3 500GB disks. Building it msstat tell me that I need wait 618 minutes? It's that correct? I'm testing it on Jaunty and a core i7 920 processor

If 618 minutes possible? To me seem to long

Regards

Ugo

Hi there,

Usually it takes that long, but you can create the array in Webmin without performing an initial diskcheck on all disks, and than it's up in seconds. Create the array in Webmin and use mdadm only for the formatting command.

Sammy.

 

[ugo1]

Hi there,

Usually it takes that long, but you can create the array in Webmin without performing an initial diskcheck on all disks, and than it's up in seconds. Create the array in Webmin and use mdadm only for the formatting command.

Sammy.

Thanks

I'm thiking to go with hardware raid, I need to use 2TB hard disk and this mean 2 days for build the array...

Is hardware raid more quick to be rebuilded?

Ugo

 

[sammynl]

You can build a 10 * 1 TB RAID5 array in 5 seconds using Webmin like this:

Only when you suspect that a memberdisk is in bad condition, or your data is worth $100.000, you should use disk initialization.

PS: If there is still persistent superblock info on your disks because you already made an array before, first delete the old superblock info from the disks. (if you don't Webmin/mdadm assumes the disks are still array members even if the array itself is already destroyed)
mdadm --zero-superblock /dev/sda1 => sdb1 sdc1 etc.

Create a new array, format it from the command line and when the format is done, mount the array.

 

[ugo1]

You can build a 10 * 1 TB RAID5 array in 5 seconds using Webmin like this:

Only when you suspect that a memberdisk is in bad condition, or your data is worth $100.000, you should use disk initialization.

PS: If there is still persistent superblock info on your disks because you already made an array before, first delete the old superblock info from the disks. (if you don't Webmin/mdadm assumes the disks are still array members even if the array itself is already destroyed)
mdadm --zero-superblock /dev/sda1 => sdb1 sdc1 etc.

Create a new array, format it from the command line and when the format is done, mount the array.

Nice tip

now i must search how made it in command line mode (i like give the number of the raid)

what about rebuilding time?

anyway my data are important to me (photos and videos), so I'm thinking to go raid 6

Regards

Ugo

n

Ugo

 

[ugo1]

Hi

This morning i Permorming some test

Client side
Win XP
hardisk: 1 sas Seagate cheetah 15k6

server side
ubuntu 9.04 64 bit
cpu core i7 920
ram 6 Gb
raid5

On small file (300 MB) Filezilla give me a very amazing results respect a trasfer to a raid 1 configuration (the gigabit lan was satured)
On largest file (12 GB) filezille give me a poor result respect a trasfer to a raid 1 configuration

Ram and cpu usage was at max on the server

How can I improve the performance on larger files?

As I said in the previous post the data I want to store are "important" data

So is the hardware raid best for me (i think to an adaptec 5805 because the driver will be Debian squeeze kernel)?. I will have more write / read performance and less rebuild time on hardware raid?

Regards

Ugo

 

[handruin]

I know it's been a while since you received an answer, but yes hardware RAID will absolutely initialize faster than software RAID. I built my RAID 5 with 5x 1.5TB Samsung F2 drives in both ways. First I used my onboard SATA controller and built the array with OpenFiler software RAID. The initialization took 30+ hours to complete.

I've since upgraded to a hardware raid controller (Dell Perc 6i) using the same hardware and OpenFiler and the array initialized in a little over 5 hours. I have benchmarks of the RAID 5 here if you want to take a look.