hardware raid 10 over raid 5
CASTalk.com Forum Index CASTalk.com
Discussion of DSP, FPGA, storage and embedded system.
 
 FAQFAQ   MemberlistMemberlist     RegisterRegister 
 ProfileProfile   Log in to check your private messagesLog in to check your private messages   Log inLog in 
 
Google
 
Web castalk.com
hardware raid 10 over raid 5

 
Post new topic   Reply to topic    CASTalk.com Forum Index -> Storage System
Author Message
thomaslally
Guest
Posted: Tue Dec 14, 2004 4:40 am    Post subject: hardware raid 10 over raid 5 Reply with quote
Disk space is not a concern, performance and above all failover
capacity are more important to us. I've seen plenty of posts about
RAID 5 and RAID 10 (1 + 0)


But, the people (such as silver Dell tech support)I was asking to are
mostly suggesting me to use RAID 5, especially HARDWARE RAID 5 with hot
spare which is not that slow compared to RAID 10, even for writing.
What do you think?


Thanks


Thomas
Back to top
Faeandar
Guest
Posted: Tue Dec 14, 2004 4:40 am    Post subject: Re: hardware raid 10 over raid 5 Reply with quote
On 13 Dec 2004 16:34:50 -0800, "thomaslally" <juste_ciel@hotmail.com>
wrote:

Quote:
Disk space is not a concern, performance and above all failover
capacity are more important to us. I've seen plenty of posts about
RAID 5 and RAID 10 (1 + 0)


But, the people (such as silver Dell tech support)I was asking to are
mostly suggesting me to use RAID 5, especially HARDWARE RAID 5 with hot
spare which is not that slow compared to RAID 10, even for writing.
What do you think?


Thanks


Thomas

Raid 1+0 is far and away more resilient than raid 5. With true 1+0
you can lose up to half of the drives in the configuration. Now if
you lose both drives of one of the mirrors then your screwed, but
below is an example.

Stripe0 Stripe1
1 1
2 2
3 3
4 4

8 drives in a 1+0 configuration. You can lose any combination of
drives as long as it's not the same drive for Stripe0 and Stripe1.
But you can lose 4 drives in this config, as long as they alternate...

Highly resilient by most standards. Also damn fast.

~F
Back to top
Fatboy40
Guest
Posted: Tue Dec 14, 2004 2:26 pm    Post subject: Re: hardware raid 10 over raid 5 Reply with quote
Faeandar,

This is an interesting post, sorry to hijack it, the chances of loosing say
both drive 1's is slim but if it does happen in a business situation then
things are going to get tricky.

I suppose it's no worse than loosing two drives in a RAID 5 array (and
loosing your parity data).

I'd be interested in your opinion ?.

Thanks, Clive.

"Faeandar" <mr_castalot@yahoo.com> wrote in message
news:ulksr059qoruqfmj3kas4itgnnea9hq86p@4ax.com...
Quote:
On 13 Dec 2004 16:34:50 -0800, "thomaslally" <juste_ciel@hotmail.com
wrote:

Disk space is not a concern, performance and above all failover
capacity are more important to us. I've seen plenty of posts about
RAID 5 and RAID 10 (1 + 0)


But, the people (such as silver Dell tech support)I was asking to are
mostly suggesting me to use RAID 5, especially HARDWARE RAID 5 with hot
spare which is not that slow compared to RAID 10, even for writing.
What do you think?


Thanks


Thomas

Raid 1+0 is far and away more resilient than raid 5. With true 1+0
you can lose up to half of the drives in the configuration. Now if
you lose both drives of one of the mirrors then your screwed, but
below is an example.

Stripe0 Stripe1
1 1
2 2
3 3
4 4

8 drives in a 1+0 configuration. You can lose any combination of
drives as long as it's not the same drive for Stripe0 and Stripe1.
But you can lose 4 drives in this config, as long as they alternate...

Highly resilient by most standards. Also damn fast.

~F
Back to top
thomaslally
Guest
Posted: Tue Dec 14, 2004 9:26 pm    Post subject: Re: hardware raid 10 over raid 5 Reply with quote
What do you think about RAID 5 with a hot spare disk? My primary
concern is safety, reliability. The RAID controllers on our servers
(Dell poweredge 2800 - 2 * 3.6 Xeon - 4GB RAM - 2 * 4 140GB) are fast.
Thanks

Thomas
Back to top
Andrew Gideon
Guest
Posted: Wed Dec 15, 2004 1:57 am    Post subject: Re: hardware raid 10 over raid 5 Reply with quote
thomaslally wrote:

Quote:
What do you think about RAID 5 with a hot spare disk?

Any reason you cannot have RAID 10 with a hot spare available for any of the
mirror pairs?

- Andrew
Back to top
Faeandar
Guest
Posted: Fri Dec 17, 2004 3:21 am    Post subject: Re: hardware raid 10 over raid 5 Reply with quote
On Tue, 14 Dec 2004 09:26:49 -0000, "Fatboy40" <no one here, sorry>
wrote:

Quote:
Faeandar,

This is an interesting post, sorry to hijack it, the chances of loosing say
both drive 1's is slim but if it does happen in a business situation then
things are going to get tricky.

I suppose it's no worse than loosing two drives in a RAID 5 array (and
loosing your parity data).

I'd be interested in your opinion ?.

Thanks, Clive.

No matter what Raid or config you put together it's always possible to
lose data, that's why we still do backups. But Raid 1+0 is much more
available than Raid 5. It's also, generally, alot faster for both
reads and writes, but at a cost (depends on the number of drives
used).

And if you lose the same mirror pair it's not "tricky", it's over.
Get out the backups.

~F

Quote:

"Faeandar" <mr_castalot@yahoo.com> wrote in message
news:ulksr059qoruqfmj3kas4itgnnea9hq86p@4ax.com...
On 13 Dec 2004 16:34:50 -0800, "thomaslally" <juste_ciel@hotmail.com
wrote:

Disk space is not a concern, performance and above all failover
capacity are more important to us. I've seen plenty of posts about
RAID 5 and RAID 10 (1 + 0)


But, the people (such as silver Dell tech support)I was asking to are
mostly suggesting me to use RAID 5, especially HARDWARE RAID 5 with hot
spare which is not that slow compared to RAID 10, even for writing.
What do you think?


Thanks


Thomas

Raid 1+0 is far and away more resilient than raid 5. With true 1+0
you can lose up to half of the drives in the configuration. Now if
you lose both drives of one of the mirrors then your screwed, but
below is an example.

Stripe0 Stripe1
1 1
2 2
3 3
4 4

8 drives in a 1+0 configuration. You can lose any combination of
drives as long as it's not the same drive for Stripe0 and Stripe1.
But you can lose 4 drives in this config, as long as they alternate...

Highly resilient by most standards. Also damn fast.

~F
Back to top
Faeandar
Guest
Posted: Fri Dec 17, 2004 3:21 am    Post subject: Re: hardware raid 10 over raid 5 Reply with quote
On Tue, 14 Dec 2004 15:57:48 -0500, Andrew Gideon
<cR182Driver45@gideon.org> wrote:

Quote:
thomaslally wrote:

What do you think about RAID 5 with a hot spare disk?

Any reason you cannot have RAID 10 with a hot spare available for any of the
mirror pairs?

- Andrew

No reason at all. In fact if you have a Raid set up and no hot spare
you're just asking to get fired.

~F
Back to top
 
Post new topic   Reply to topic    CASTalk.com Forum Index -> Storage System All times are GMT
Page 1 of 1

 
 You cannot post new topics in this forum
You cannot reply to topics in this forum
You cannot edit your posts in this forum
You cannot delete your posts in this forum
You cannot vote in polls in this forum




VoIP Electronics Powered by phpBB