On Thu, Nov 08, 2001 at 03:36:28PM -0800, nate wrote: > David Priban said: > > What exactly is the issue you are talking about? > > I was just about to build a system using 6410 raid 5 :( > > > > Also couple of weeks ago 3ware announced it is going to > > discontinue Escalade line of products. This makes me wonder > > if this issue will ever get fixed. > > Just checking 3ware website and the announcement is not there > > any more. Just a broken link. I really hope they changed > > their minds... > > > well i don't know how to describe it. for a long time they had > me confused wether it was IBM 75GXP drives causing problems or > 3ware(turned out it was both). the western regional sales guy > called me(and my boss) a couple months ago(at the request of > my vendor) and told me the situation. not much details other then > there is a known problem in the raid5 implimentation on all of > their cards. they thought they had it fixed in the 7000 series > which i recieved one, only to be later told do NOT use it as it > apparently had a worse problem. one of my systems completely crapped > out, and we dropped it off at the vendor, 3ware cameon site and looked at > it(don't know what they did), they said > they will have a fix soon(this was back in september), last > i heard the fix was due mid november 2001. that to me doesn't > mean it will work though. i have since switched from 4x80GB > maxtors in RAID5 (was originally 4x75GB IBMs) to 6x80GB > maxtors in raid 10. i asked my vendor to let me know in 6 months > if the raid5 stuff on 3ware works and i will switch back > then if it does. > > the people at 3ware will probably admit to you if you contact > them of the problem in raid5 i don't believe they are trying > to keep it secret. their raid10 and raid0 systems apparently > have been in running/production for about 18 months longer > then raid5 and have no known problems. > > i don't know the details of the problem in raid5 and can't > really describe the symtoms as what i was suffering from was > crappy disks(75GXP, had 5 fail in 30 days), and the raid > card itself.
I remember reading about these problems a little while back when I was considering using the 3ware raid cards - I too was very interested in RAID 5. I may however got this mixed up with Promise - check reviews of the cards for full accuracy! From what I can remember, 3ware originally designed the cards for RAID 0, 1, 10 only. The hardware on the card can do these modes well and fast as it is done properly in the logic on the card. They then realised that the demand for RAID 5 was great and so kludged together a software version - the XOR calculations were done by the embedded OS on the card rather than the raw logic. Thus the performance is much worse. Since then they've always been tweaking it to try to get it to work properly - and as we've heard, it doesn't. If you're going to be setting up a dedicated fileserver then you will probably not get a severe performance hit if you just use software RAID 5 in the kernel - i've been using it here for some months with no problems: just follow the HOWTOs and it's not really too difficult to set up. If you can afford it then go for a SCSI solution - it'll work. :-) Matthew -- Matthew Sackman Nottingham, ENGLAND --------------------------------------------------------------------- The contents of this email are intended for the indicated recipient(s) only. This may or may not be indicated in the above email as it is enormously easy to fake email addresses (see the relevant RFCs). For security reasons this email is likely to be gnupg signed. On the other hand it may not be if I forgot to do so. In any case, if you are reading this on a Windows based computer then there was no point in me doing so (provided that I remembered) as your computer is most likely being used by yourself and 2.8 other people at the same time (normally without your consent). No responsibility will be accepted by anyone for any of the contents of this email. So tough. If in doubt, go compile Mozilla. --------------------------------------------------------------------
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