Message: 31 Date: Tue, 15 May 2007 11:25:42 +0800 From: Feizhou feizhou@graffiti.net Subject: Re: [CentOS] Re: Anaconda doesn't support raid10 Message-ID: 46492836.3010808@graffiti.net
<snip> <the reliability factor has been proven to be the same across the board. <You must have missed the thread on the Google report on various drives <that they use
Feizhou: Yes, I did not see that. If the MTBF's are the same, then the Performance specs you provided are what one needs to go with, when choosing components. If Google has posted Failure rates, for the drives they use, that would be more meaningful than MTBF by the drive manufacturer, for that particular drive model.
Questions: Is it your belief that all PATA/SATA/SCSI drives made by one manufacturer have the same MTBF? (I find that hard to believe. However, that might be the case.....) Also, is it your belief that these drives, made by different manufacturers, all have the same MTBF?
Who says? You? I like to have an online offsite RAID backup server. Is there an ONE TRUE WAY OF BACKUP?
No. Obviously, there is no one true way of backup. Everyone's needs are different. Your online off site RAID backup server is one way. Backups *must* be off site, in the event of a catastrophic problem.
Thank you, for sharing your time and knowledge with the list! Lanny
Lanny Marcus wrote:
Questions: Is it your belief that all PATA/SATA/SCSI drives made by one manufacturer have the same MTBF? (I find that hard to believe. However, that might be the case.....) Also, is it your belief that these drives, made by different manufacturers, all have the same MTBF?
I believe that there's not enough difference to matter. There is always enough of a chance of a failure that you have to be prepared for it and pretty much all of the vendors have made bad batches. But, these days they are good enough that if you don't abuse them with flakey power or high temperatures, 80% or more will last until you want to replace the equipment for some other reason (5 years or more). The ones that fail will pick random times to do it, though.
Les Mikesell wrote:
Lanny Marcus wrote:
Questions: Is it your belief that all PATA/SATA/SCSI drives made by one manufacturer have the same MTBF? (I find that hard to believe. However, that might be the case.....) Also, is it your belief that these drives, made by different manufacturers, all have the same MTBF?
I believe that there's not enough difference to matter. There is always enough of a chance of a failure that you have to be prepared for it and pretty much all of the vendors have made bad batches. But, these days they are good enough that if you don't abuse them with flakey power or high temperatures, 80% or more will last until you want to replace the equipment for some other reason (5 years or more). The ones that fail will pick random times to do it, though.
and fluctuating temperatures. That is what the Google report and another one found that drastically reduced life expectancy. Running drives at 60 degrees centigrade may or may not induce death in a month (cannot remember whether they continued long after cooling was rectified) so long as the temperature is stable. Fluctuating temperatures even at 30-35 range can kill a disk faster than a stable high temperature. Ain't it nice that smartctl alerts you of a change in temperature?
Lanny Marcus wrote:
Message: 31 Date: Tue, 15 May 2007 11:25:42 +0800 From: Feizhou feizhou@graffiti.net Subject: Re: [CentOS] Re: Anaconda doesn't support raid10 Message-ID: 46492836.3010808@graffiti.net
<snip> <the reliability factor has been proven to be the same across the board. <You must have missed the thread on the Google report on various drives <that they use
Feizhou: Yes, I did not see that. If the MTBF's are the same, then the Performance specs you provided are what one needs to go with, when choosing components. If Google has posted Failure rates, for the drives they use, that would be more meaningful than MTBF by the drive manufacturer, for that particular drive model.
They noted that there was no particular difference in failure rates whether they are high performance industrial drives or consumer drives. Basically they said that manufacturers claims of MBTF amounted to naught. It was the operating environment that determined the failure rate of drives, namely, fluctuating temperatures.
Questions: Is it your belief that all PATA/SATA/SCSI drives made by one manufacturer have the same MTBF? (I find that hard to believe. However, that might be the case.....) Also, is it your belief that these drives, made by different manufacturers, all have the same MTBF?
Bad batches aside, no I do not believe that different drives from different manufacturers have the same MTBF. Case in point are the IBM 'glass' Deskstars. However, I personally choose Seagate drives and I have not had problems with them. In my previous job at an ISP, they used maxtors and western digital drives and I did not notice any particular brand being more troublesome (firmware and controller incompatibilities excepted) nor do I get the impression that they were better or worse than Seagate. I have no comment on newer manufacturers like Hitachi.
Due to the fact that those boxes run 24/7, I believe that that enabled consumer drives to last longer than they would due to less temperature fluctuations.
-
Feizhou -
Lanny Marcus -
Les Mikesell