From 2874606d9fdc907bca999e6228e58ec71bb681d7 Mon Sep 17 00:00:00 2001 From: Markus Birth Date: Mon, 29 May 2017 19:32:42 +0200 Subject: [PATCH] More info about reshape speed. --- .../2017-05-28-speed-up-synology-reshape.md | 25 ++++++++++++++++++- 1 file changed, 24 insertions(+), 1 deletion(-) diff --git a/know-how/hardware/_posts/2017-05-28-speed-up-synology-reshape.md b/know-how/hardware/_posts/2017-05-28-speed-up-synology-reshape.md index 9e6a08a..d93db9d 100644 --- a/know-how/hardware/_posts/2017-05-28-speed-up-synology-reshape.md +++ b/know-how/hardware/_posts/2017-05-28-speed-up-synology-reshape.md @@ -3,7 +3,7 @@ title: Speed up Synology volume reshaping layout: default language: en created: 2017-05-28 23:45:40 +0200 -updated: 2017-05-28 23:45:40 +0200 +updated: 2017-05-29 19:22:31 +0200 toc: false tags: - know-how @@ -144,6 +144,29 @@ md3 : active raid5 sdd6[2] sda6[0] sdb6[1] ``` +UPDATE +====== + +After replacing the second disk, there was another *reshape* going on, but this time, the speed +lingered at 20-30 MB/sec which isn't much given that it went up to 80 MB/sec for the first disk. + +However, after some more research, I found [this comment](https://www.cyberciti.biz/tips/linux-raid-increase-resync-rebuild-speed.html#comment-20767) +which explained how the system only speeds up to `speed_limit_max` when there's no other disk I/O +going on and otherwise keeps the speed at `speed_limit_min`. That made sense as the default +`speed_limit_min` is `10000` (or 10 MB/sec) and I already increased it to `20000` yesterday. + +Why the Synology thought there was other activity and kept the transfer speed down, I don't know. + +But now I increased the minimum speed further to 60 MB/s: + + sysctl -w dev.raid.speed_limit_min=60000 + +And suddenly the reshaping speed also increased to around 60 MB/sec. I slightly increased it +further until I ended up at a value of `90000` (90 MB/s) and a real speed of around +80-90 MB/sec. + +This cut the remaining time down from 12 hours to 3. + *[MiB]: Mebibyte (1024 KiB), similar to Megabyte (1000 kB)