Hello all,
Testing stuff virtually over here before taking it to the physical servers.
I found a shortcut for creating a software RAID 10 ("--level=10"), device in CentOS 6.
Looking at the below, I don't see anything about a shortcut for RAID 60. https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/htm l/Storage_Administration_Guide/s1-raid-levels.html
Is RAID 60 an uncommon RAID-configuration, as compared to RAID 10, and this might be why it's missing?
Not too cumbersome to first create two RAID 6-arrays, then add them to a RAID 0, but it does take some extra time. Besides, I haven't found any way to fail a member disk, as is possible to do when using RAID level 10.
Am I missing something here?
On 10/25/2016 05:41 AM, Sorin Srbu wrote:
I found a shortcut for creating a software RAID 10 ("--level=10"), device in CentOS 6.
That's not really a shortcut, per se. RAID10 in Linux is not necessarily similar to RAID1+0. The default, "near" layout is the classic 1+0 layout, but other modes of operation are supported by the RAID10 driver.
Looking at the below, I don't see anything about a shortcut for RAID 60.
Correct. There's no such driver.
Besides, I haven't found any way to fail a member disk, as is possible to do when using RAID level 10.
If you built a RAID0 array of RAID6 arrays, then you'd fail a disk by marking it failed and removing it from whichever RAID6 array it was a member of, in the same fashion as you'd remove it from any other array type.
-----Original Message----- From: centos-bounces@centos.org [mailto:centos-bounces@centos.org] On Behalf Of Gordon Messmer Sent: den 25 oktober 2016 20:54 To: CentOS mailing list centos@centos.org Subject: Re: [CentOS] "Shortcut" for creating a software RAID 60?
On 10/25/2016 05:41 AM, Sorin Srbu wrote:
I found a shortcut for creating a software RAID 10 ("--level=10"),
device in
CentOS 6.
That's not really a shortcut, per se. RAID10 in Linux is not necessarily similar to RAID1+0. The default, "near" layout is the classic 1+0 layout, but other modes of operation are supported by the RAID10 driver.
Thanks for the clarification. Close enough though, for my intended use!
You mention modes however. I don't recall seeing any particular info on that.
Care to elaborate a bit on that, if it's not too OT?
Besides, I haven't found any way to fail a member disk, as is possible
to do
when using RAID level 10.
If you built a RAID0 array of RAID6 arrays, then you'd fail a disk by marking it failed and removing it from whichever RAID6 array it was a member of, in the same fashion as you'd remove it from any other array type.
Aha, thanks!
-----Original Message----- From: centos-bounces@centos.org [mailto:centos-bounces@centos.org] On Behalf Of Gordon Messmer Sent: den 25 oktober 2016 20:54 To: CentOS mailing list centos@centos.org Subject: Re: [CentOS] "Shortcut" for creating a software RAID 60?
That's not really a shortcut, per se. RAID10 in Linux is not necessarily similar to RAID1+0. The default, "near" layout is the classic 1+0 layout, but other modes of operation are supported by the RAID10 driver.
You mention modes however. I don't recall seeing any particular info on that.
Care to elaborate a bit on that, if it's not too OT?
Never mind. Found this to start with.
http://www.ilsistemista.net/index.php/linux-a-unix/35-linux-software-raid-10 -layouts-performance-near-far-and-offset-benchmark-analysis.html?start=1
-----Original Message----- From: centos-bounces@centos.org [mailto:centos-bounces@centos.org] On Behalf Of Gordon Messmer Sent: den 26 oktober 2016 08:25 To: CentOS mailing list centos@centos.org Subject: Re: [CentOS] "Shortcut" for creating a software RAID 60?
On 10/25/2016 10:41 PM, Sorin Srbu wrote:
Never mind. Found this to start with.
Additionally, see the man page for "md".
Gotcha'. Thanks.
On 10/25/2016 11:54 AM, Gordon Messmer wrote:
If you built a RAID0 array of RAID6 arrays, then you'd fail a disk by marking it failed and removing it from whichever RAID6 array it was a member of, in the same fashion as you'd remove it from any other array type.
FWIW, what I've done in the past is build the raid 6's with mdraid, then use LVM to stripe them into a volume group.
-----Original Message----- From: centos-bounces@centos.org [mailto:centos-bounces@centos.org] On Behalf Of John R Pierce Sent: den 26 oktober 2016 07:42 To: centos@centos.org Subject: Re: [CentOS] "Shortcut" for creating a software RAID 60?
On 10/25/2016 11:54 AM, Gordon Messmer wrote:
If you built a RAID0 array of RAID6 arrays, then you'd fail a disk by marking it failed and removing it from whichever RAID6 array it was a member of, in the same fashion as you'd remove it from any other array type.
FWIW, what I've done in the past is build the raid 6's with mdraid, then use LVM to stripe them into a volume group.
What's the advantage doing it that way?
Ease of maintenance maybe?
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Gordon Messmer -
John R Pierce -
Sorin Srbu