Gentoo Archives: gentoo-user

From: Paul Hartman <paul.hartman+gentoo@×××××.com>
To: Gentoo User <gentoo-user@l.g.o>
Subject: Re: [gentoo-user] Comparing RAID5/6 rebuild times, SATA vs SAS vs SSD
Date: Fri, 20 Sep 2013 22:44:14
Message-Id: CAEH5T2MDPTnmCTR+-arWao6UivuSc8aQu1Gp1urH-ODZSae8Pw@mail.gmail.com
In Reply to: [gentoo-user] Comparing RAID5/6 rebuild times, SATA vs SAS vs SSD by Tanstaafl
1 On Fri, Sep 20, 2013 at 6:20 AM, Tanstaafl <tanstaafl@×××××××××××.org> wrote:
2 > Hi all,
3 >
4 > Being that one of the big reasons I stopped using RAID5/6 was the rebuild
5 > times - can be DAYS for a large array - I am very curious if anyone has
6 > done, or knows of anyone who has done any tests comparing rebuild times when
7 > using slow SATA, faster SAS and fastest SSD drives.
8 >
9 > Of course, this question is moot if using ZFS RAID, but not every situation
10 > or circumstance will allow it...
11
12 I don't have an all-out comparison, but at least a data point for you
13 with somewhat cheap and recent hardware. I have a new (2 months old)
14 home RAID6 made out of:
15
16 6 Western Digital Red 3TB SATA drives
17 LSI 9200-8e SAS JBOD controller
18 Sans Digital TR8X+B SAS/SATA enclosure w/ SFF-8088 cables
19
20 I created a standard linux software RAID6 using mdadm, resulting in
21 11TB of usable space (4 data drives, 2 parity).
22
23 A couple weeks ago one of the drives died. I hot-swap replaced it with
24 a new one (with no down-time) and the rebuild took exactly 10 hours.
25
26 Under normal operation, the speed of the array for contiguous
27 read/writes is about 600MB/sec, which is faster than my SSD (single
28 drive, not RAIDed).
29
30 FWIW

Replies

Subject Author
Re: [gentoo-user] Comparing RAID5/6 rebuild times, SATA vs SAS vs SSD Tanstaafl <tanstaafl@×××××××××××.org>