Comments on: RAID reliability calculations http://storageadvisors.adaptec.com/2005/11/01/raid-reliability-calculations/ Storage Solutions for Real World IT Professionals Sat, 21 Nov 2009 05:45:31 +0000 http://wordpress.org/?v=1.5.2 Comment on RAID reliability calculations by: Neil http://storageadvisors.adaptec.com/2005/11/01/raid-reliability-calculations/#comment-363625 Sun, 18 Oct 2009 21:33:24 +0000 http://storageadvisors.adaptec.com/2005/11/01/raid-reliability-calculations/#comment-363625 Coldfusion ... Yes RAID 1 is a very valid RAID level, and with the size of disks available today it can supply a useful system to a large number of organisations. My only concern with this RAID level is performance (which is not terribly good due to only 2 spindles in the system). However, take a look at our new MAXIQ caching module. In combination with a RAID 1 it can give your webservers a ginormous kick in the pants when it comes to performance without compromising on the integrity (safety) of your data. Ciao Neil Coldfusion …

Yes RAID 1 is a very valid RAID level, and with the size of disks available today it can supply a useful system to a large number of organisations. My only concern with this RAID level is performance (which is not terribly good due to only 2 spindles in the system).

However, take a look at our new MAXIQ caching module. In combination with a RAID 1 it can give your webservers a ginormous kick in the pants when it comes to performance without compromising on the integrity (safety) of your data.

Ciao
Neil

]]> Comment on RAID reliability calculations by: ColdFusion Developer http://storageadvisors.adaptec.com/2005/11/01/raid-reliability-calculations/#comment-363546 Sat, 17 Oct 2009 06:00:23 +0000 http://storageadvisors.adaptec.com/2005/11/01/raid-reliability-calculations/#comment-363546 Good article. I've always been a fan of RAID 1 on my primary work machine and for each of my web servers. It seems to be the sweet spot in terms of reliability and cost benefit. Good article. I’ve always been a fan of RAID 1 on my primary work machine and for each of my web servers. It seems to be the sweet spot in terms of reliability and cost benefit.

]]> Comment on RAID reliability calculations by: Mike http://storageadvisors.adaptec.com/2005/11/01/raid-reliability-calculations/#comment-32941 Fri, 09 Feb 2007 20:13:06 +0000 http://storageadvisors.adaptec.com/2005/11/01/raid-reliability-calculations/#comment-32941 Just wanted to drop a thank you note to Ernst. Much appreciated. Thanks, Mike Just wanted to drop a thank you note to Ernst. Much appreciated.
Thanks,
Mike

]]> Comment on RAID reliability calculations by: Mike http://storageadvisors.adaptec.com/2005/11/01/raid-reliability-calculations/#comment-18535 Wed, 15 Nov 2006 14:55:27 +0000 http://storageadvisors.adaptec.com/2005/11/01/raid-reliability-calculations/#comment-18535 Tom, Thanks for checking. I too am a bit surprised over the low MTBF rating. The component reliability assessment thing probably uses a Belcore tool that adds up the component FIT rating. Disk drives certainly have come a long ways in terms of reliability and I guess I expected RAID Cards to keep pace. I found this additional info. The published MTBF for the new LSI SAS RAID controller is 200,000 Hrs. Wow is that low! I did see others anywhere from 1M hrs to 1.75 hr MTBF. I may go ahead and use 1M hr in my model for now. Thanks, Mike Tom,

Thanks for checking. I too am a bit surprised over the low MTBF rating. The component reliability assessment thing probably uses a Belcore tool that adds up the component FIT rating. Disk drives certainly have come a long ways in terms of reliability and I guess I expected RAID Cards to keep pace. I found this additional info. The published MTBF for the new LSI SAS RAID controller is 200,000 Hrs. Wow is that low! I did see others anywhere from 1M hrs to 1.75 hr MTBF. I may go ahead and use 1M hr in my model for now.

Thanks,
Mike

]]> Comment on RAID reliability calculations by: Ernst Lopes Cardozo http://storageadvisors.adaptec.com/2005/11/01/raid-reliability-calculations/#comment-18414 Tue, 14 Nov 2006 16:30:12 +0000 http://storageadvisors.adaptec.com/2005/11/01/raid-reliability-calculations/#comment-18414 The answers to the question of colntroller MTBF are quite amazing. Google found http://www.intel.com/support/motherboards/server/sb/cs-020405.htm, which shows MTBF for various Intel controllers at 40 degree Celsius to run from a low 0.284 Mh (milion hours) to 2.2 Mh. Both the low values and the difference of almost an order of magnitude are suprising. These numbers suggest that in calculating the time to data loss (TTDL) the RAID hardware must be taken into account. The answers to the question of colntroller MTBF are quite amazing. Google found http://www.intel.com/support/motherboards/server/sb/cs-020405.htm, which shows MTBF for various Intel controllers at 40 degree Celsius to run from a low 0.284 Mh (milion hours) to 2.2 Mh. Both the low values and the difference of almost an order of magnitude are suprising. These numbers suggest that in calculating the time to data loss (TTDL) the RAID hardware must be taken into account.

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