Re: RAID-1 - suboptimal write performance?

2014-05-23 Thread Roman Mamedov
On Fri, 16 May 2014 17:36:57 -0400 Austin S Hemmelgarn ahferro...@gmail.com wrote: It's similar (writes to just one drive, while the other is idle) when removing (many) snapshots. Not sure if that's optimal behaviour. I think, after having looked at some of the code, that I know

Re: RAID-1 - suboptimal write performance?

2014-05-18 Thread Brendan Hide
On 2014/05/16 11:36 PM, Austin S Hemmelgarn wrote: On 05/16/2014 04:41 PM, Tomasz Chmielewski wrote: On Fri, 16 May 2014 14:06:24 -0400 Calvin Walton calvin.wal...@kepstin.ca wrote: No comment on the performance issue, other than to say that I've seen similar on RAID-10 before, I think.

RAID-1 - suboptimal write performance?

2014-05-16 Thread Tomasz Chmielewski
While doing rsyncs of large archives from one RAID-1 btrfs filesystem to another RAID-1 btrfs filesystem: btrfs filesystem 1: sda + sdb (RAID-1), being copied to: btrfs filesystem 2: sdc + sdd (RAID-1) Server has 32 GB RAM I can observe the following: From time to time, rsync freezes, while

Re: RAID-1 - suboptimal write performance?

2014-05-16 Thread Tomasz Chmielewski
On Fri, 16 May 2014 14:06:24 -0400 Calvin Walton calvin.wal...@kepstin.ca wrote: No comment on the performance issue, other than to say that I've seen similar on RAID-10 before, I think. Also, what happens when the system crashes, and one drive has several hundred megabytes data more than

Re: RAID-1 - suboptimal write performance?

2014-05-16 Thread Austin S Hemmelgarn
On 05/16/2014 04:41 PM, Tomasz Chmielewski wrote: On Fri, 16 May 2014 14:06:24 -0400 Calvin Walton calvin.wal...@kepstin.ca wrote: No comment on the performance issue, other than to say that I've seen similar on RAID-10 before, I think. Also, what happens when the system crashes, and one