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Brad Fitzpatrick

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RAID [Nov. 25th, 2003|04:09 pm]
Brad Fitzpatrick
LiveJournal uses or has used:

Linux software RAID
AMI/Dell/LSI/whatever MegaRAID
Mylex DAC960 RAID
Adaptec RAID
Intel gdth RAID

They all suck in different ways:

Adaptec corrupted data left and right. We replaced them all. MegaRAID has shitty, closed, unuseable tools and shitty /proc interfaces. Intel gdth is good with nice /proc interfaces, but some tools aren't so quick returning. None of them have anything near a consistent interface. IBM ServRAID seems great, but I think the control binary is closed? Maybe it's not anymore, with IBM being all pro-Linux. That was years ago. Still my favorite RAID array.

I really can't recommend any one of them. No, DAC960 is definitely the best.... no question. But they were bought and that line discontinued. :-(


[User Picture]From: scsi
2003-11-25 04:13 pm (UTC)
ICP Vortex raid card = Crap. They had raid drivers out before Adaptec did back in the days, but it just sucks... I'm suprised that adaptec gave you troubles, I hope it doesnt hit my machines (though I'm using zero channel raid that does not use the aacraid module, I use the i2osomething i believe).. :(
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[User Picture]From: brad
2003-11-25 04:14 pm (UTC)
Wait, which one's ICP Vortex? The gdth one? (they all buy each other and have 400 names)

Why is it crap? We haven't had any problems with it yet.... :-/
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[User Picture]From: scsi
2003-11-25 04:20 pm (UTC)
Im not sure what kernel driver it uses, i'll look and mail ya. It was just horrible in the rare case a drive went bad. The interface was completely useless and confusing, and the tools to manage the raid (while the machine was running) would randomly lock up the raid card.. If you built a standard raid 5 array, and just ran it without any disk issues happening, it was okay (until a drive went out, then you crossed your fingers as you tried to navigate through the crap inteface to replace it)..
This is back from ~99-00, so things might of gotten a wee bit better..
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[User Picture]From: scsi
2003-11-26 08:17 am (UTC)
Its the old gdt driver I think before they merged them with Intel and popped out gdth
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[User Picture]From: krow
2003-11-25 04:13 pm (UTC)
I have had huge problems with Mylex over the years. I once mentioned this in an article on Slashdot and ended up with a long set of comments where others felt the need to express their dislike of them too.

Not sure if MegaRaid and MegaDrive are the same thing, but they once royally screwed me over on hardware that never functioned and died weekly. When I brought it up with them 6 months into the deal they offered to give me a 10% discount on their next product if I exchanged my old hardware for new.

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[User Picture]From: brad
2003-11-25 04:15 pm (UTC)
Who do you recommend, if anybody?

LSI now owns MegaRAID. AMI used to.
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[User Picture]From: krow
2003-11-25 05:04 pm (UTC)
I've not found any I like :(
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[User Picture]From: grumpy_sysadmin
2003-11-25 05:40 pm (UTC)

This will get screened BUT

Limiting myself to PCI-card based RAID, IBM ServeRAID still rocks. Rebuilds quickly on the fly, while the system is running, automatically when you replace a disk, without any software interface at all. (I've done this on an IBM xSeries 345, replacing the built-in SCSI card--which isn't ServeRAID and can only do RAID 0 or 1--with a ServeRAID-4Lx, while the box was still in active Oracle production.) I've only used their control stuff from the BIOS; haven't needed any further interface with it and I've had four machines with ServeRAIDs in production for about a year now. But I also have 24/7 computer operators to page me if there are blinking amber lights, so maybe I'm not in the same place you are.

I try to avoid limiting myself to PCI-card based RAID, though. I've got about 7 TB (useable; 8.67 raw) worth of Xyratex 1 Gb fibre channel arbitrated loop (copper HSSDC connectors) that I'm basically happy with. They've been cranky from time to time, but if you treat them right they're fine (email my lj address if you want details on the history). Xyratex is frequently resold under other names. The use a Mylex DAC9600 for that array. I don't really have complaints about it... but it's a fibre channel controller pair (with seamless hardware failover between the two controllers, assuming you've got something like Veritas running on the host). I've been less-than-impressed with Mylex PCI SCSI cards.

I'm build-time away from playing with 3 (useable; 4 raw) TB of Zzyzx StingRAID (which is actually a Infortrend dual active controller pair set up at least, and probably really an Infortrend chassis). It's als FC-AL, but 2 Gb using actual glass and LC connectors, and it uses SATA disk. From the conversations I've had with references Zzyzx provided, I expect to be basically content using it for backup staging and as disk on a NAS head (for which I'm using a Sun E450 running Solaris 9).

If you're in California and north or on the East Coast (can't speak for the middle time zones) Zzyzx is a good storage reseller to go talk to. On the left coast, tell Chris P. that gr from PA (or email me and get my real name; not putting it here for don't-want-work-to-find-my-lj reasons) sent you. On the East Coast, tell Dave G. the same. They resell Xyratex for real FC-AL arrays (or they did the last time I checked) and they sell "their own" (which is actually rebranded Infortrend) and Nexsan for serial (Infortrend) and parallel (Nexsan) ATA-behind-FC arrays. They also sell Overland tape libraries (they make a good, gracefully expandable, LTO2 library; the Neo 4x00 line).

I just ranted about SAN/NAS stuff over in unixadmin a couple of times. This is the condensed version of those posts.
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[User Picture]From: brad
2003-11-25 05:57 pm (UTC)

Re: This will get screened BUT

Interesting... and thanks for the mention of unixadmin.
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[User Picture]From: funjon
2003-11-25 06:42 pm (UTC)
I know IDE raid isn't popular because "ide is slow" (which is bullshit), but I still haven't run my 3Ware Escalade controllers out of IO bandwidth. I so crave an 8506-12 (12 port SATA) and 12 disks... mmmm, fast.
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[User Picture]From: xunker
2003-11-25 10:10 pm (UTC)

Gotta love the Mylex, except when they suck.

I became a big believer in Mylex in the last few months myself; got one of the super-economy Mylex 170LP controllers that even with its bargain price utterly trounces anything I've used before -- Hardware and software IDE raid and even the cheaper Adaptec scsi raid cards I've tried.

Of course, they are not without their flaws; in my case, the two primary ICs on either side of the card run blisteringly hot even without a load, sometimes locking the machine utterly. Seems to be just a 150/160/170 issue, and I've talked to a few other owners who notice the same thing though, lucky me, I'm one of the few running one in a high-demand application where it actually makes the machine fall down.
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[User Picture]From: octal
2003-11-26 02:09 pm (UTC)
3ware escalade.
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[User Picture]From: brad
2003-11-26 02:21 pm (UTC)
Oh, we use those too.

But I'm mostly talking SCSI.
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