LVM2 stripe performance
I'm running tiobench on an LVM2 striped logical volume. I'm comparing the LVM2 striping performance with a similar striping configuration using a hardware RAID controller.
With hardware RAID, I'm able to get about 66 megabytes per second on sequential writes, and 52 megabytes per second with random writes.
With LVM2, I can get only 23 megabytes per second with either random or sequential writes.
Read performance on LVM is about 10% less than with hardware RAID. e.g. with 48 threads, hardware RAID sequental reads are 105 megabytes per second, LVM2 RAID sequential reads are 95 megabytes per second.
This is using an ext2 file system, mounted with noatime.
I think I recall seeing email with similar problems to this on this mail list. If I recall, the cause had to do with ordering of requests submitted to disk.
Has there been any work to address this?
Thanks!
Dave Olien
Quoted 15 lines · Dave Olien
I'm running tiobench on an LVM2 striped logical volume. I'm comparing the LVM2 striping performance with a similar striping configuration using a hardware RAID controller.
With hardware RAID, I'm able to get about 66 megabytes per second on sequential writes, and 52 megabytes per second with random writes.
With LVM2, I can get only 23 megabytes per second with either random or sequential writes.
Read performance on LVM is about 10% less than with hardware RAID. e.g. with 48 threads, hardware RAID sequental reads are 105 megabytes per second, LVM2 RAID sequential reads are 95 megabytes per second.
Quoted 7 lines
This is using an ext2 file system, mounted with noatime.
I think I recall seeing email with similar problems to this on this mail list. If I recall, the cause had to do with ordering of requests submitted to disk.
Has there been any work to address this?
Try the latest -mm kernel
- Joe