lance_corporal_jones
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SBS Server - RAID1 vs RAID5 for reliability
Hi Guys
I've been working with servers for a while (mostly for small business customers), when ordering new servers (Always Dell) I normally go for a mirror (2 drives) for the OS and RAID5 (with 3 drives) for the Data, the data is always backed up to tape or external USB/NAS drives as well and not totally reliant on RAID for backup purposes.
My query is, is RAID5 actually reliable?, I meet a lot of techs and some have told me they have had bad experiences with RAID5 where one drive goes down and putting in a new drive doesnt actually rebuild the data so now they only use RAID mirrors.
Secondly (and more importantly) if I did have a server with RAID1 and one of the drives failed, if for some reason the controller failed as well and I could not put in a new controller of similar type will the drive work as a standalone drive?, or put another way does the hard drive have data on it that relies on the RAID controller in any way or can I put it on another completely different bare metal system and see 100% of the data.
I've been working with servers for a while (mostly for small business customers), when ordering new servers (Always Dell) I normally go for a mirror (2 drives) for the OS and RAID5 (with 3 drives) for the Data, the data is always backed up to tape or external USB/NAS drives as well and not totally reliant on RAID for backup purposes.
My query is, is RAID5 actually reliable?, I meet a lot of techs and some have told me they have had bad experiences with RAID5 where one drive goes down and putting in a new drive doesnt actually rebuild the data so now they only use RAID mirrors.
Secondly (and more importantly) if I did have a server with RAID1 and one of the drives failed, if for some reason the controller failed as well and I could not put in a new controller of similar type will the drive work as a standalone drive?, or put another way does the hard drive have data on it that relies on the RAID controller in any way or can I put it on another completely different bare metal system and see 100% of the data.
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ASKER
Thanks for the answers guys.
leew, just to clarify, are you saying in most cases I should be able to take a RAID1 mirror drive and put it in a completely different system and access the data? (just want to confirm theres nothing special done to the data that makes it unreadable)
leew, just to clarify, are you saying in most cases I should be able to take a RAID1 mirror drive and put it in a completely different system and access the data? (just want to confirm theres nothing special done to the data that makes it unreadable)
Yes, in most cases (every case I've personally experienced - not that I've had to do this often). I say most because in a prior question, another expert suggested that SOME controllers, DO do something special to the drive config.
ASKER
Thanks leew and also rindi for your input, I think I will start going with RAID1 for future Dell servers.
I'll leave this question open a little while longer as its always good to get more input of peoples experiences, if none are received by end of this week I'll accept the multiple answers.
I'll leave this question open a little while longer as its always good to get more input of peoples experiences, if none are received by end of this week I'll accept the multiple answers.
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Backups are ALWAYS important... but the experiences I had with various SUPPOSEDLY good RAID cards, INCLUDING Adaptec, LSI Logic, and others left me with a bad taste in my mouth. The idea behind RAID is to increase uptime - NOT act as a backup - so backup is, to an extent, irrelevant to the question. When you have a RAID 5 go down because a hiccup on the SCSI bus, this is BAD.
I'll back track a *LITTLE* - RAID 5 on a nice, high-end SAN is fine. Never had a problem with a RAID 5 on the fiber channel SAN I used to manage and I had several RAID 5s on that. That taste (and subsequently hearing about 3WARE cards where I used to work failing on SATA and PATA RAIDs) has left me tainted to the point where I don't want to risk it on anything less than Fiber Channel.
I'll back track a *LITTLE* - RAID 5 on a nice, high-end SAN is fine. Never had a problem with a RAID 5 on the fiber channel SAN I used to manage and I had several RAID 5s on that. That taste (and subsequently hearing about 3WARE cards where I used to work failing on SATA and PATA RAIDs) has left me tainted to the point where I don't want to risk it on anything less than Fiber Channel.
You could see the data you would have to so a repair on the server mostly change the sid and reomce the raid controller driver.
CT