EqualLogic PS5000E array creation issue

[Thuleman]

Yeah, I do have support, but it's 5-day, and the weekend just about started.

I initialized the box, created a group ..., and was not given a choice to create arrays?!
By group policy I am using Raid5, it created one hot spare, and it made 3.06TB available for LUN creation.

The unit holds 16 250GB drives. One hot spare means 15 left. One for parity, 14 left, which should add up to 3.5 TB. I conclude that it was smart enough to create three 5-disk arrays, hence there are 12 usable drives (one to hot swap, three to each array for parity), which would result in 3 TB usable space, close enough to the 3.06 TB reported?

Anyone have a unit like that can could confirm?

 

[Razlak]

Base 10 (What hard drives are sold as) to Base 2 (What computers use) conversion factor....

14 x 250GB (Base 10 bytes)=3,500,000,000,000

3,500,000,000,000 / 2^40 = 3.18TB (Base 2 Bytes)

I'm guessing the rest is lost to some formatting overhead.

 

[Thuleman]

Razlak was of course correct.

After spending some time on the phone with the EQL folks I learned that the PS5000E can not be carved up into multiple arrays. The way their controller works is that it can't properly optimize IO if multiple arrays are present.

That's that.

 

[AreEss]

$60,000 for less than half the performance and less than 10% of the features of an $8k 2.5TB SAS shelf on an LSI 8480.

Too late to demand your money back? They only get worse. I demo'd one before the Dell buyout.

EDIT: BTW, because of the way EqualLogic formats things, you lose more than the typical single parity disk overhead. (Also, I have the wrong notes here. But trust me, those things are abysmal at their pinnacle. You can do better for much much less.)

 

[Thuleman]

No one ever got fired for buying a Cisco router, eh? Same applies here. There was no time to demo the unit, cash had to be spent. GSA vendor was called, system was specced out and bought, done and done. The PS5000E with 16x 250GB drives and one year of support set us $22K back.

Sure, a whitebox clubbed together SAN would have been less expensive, but if something doesn't work it's easy to sell "Well, it's a Dell thing!" rather than "Uhm ...., yeah ... I bought this stuff, not sure, this cable goes there, pretty sure about that ..., the one setting worked yesterday, not sure why it doesn't work today, weird ...", you get the idea. SAN prices are what they are, it's the cost of doing business.

I actually set the unit up as RAID50 now, when I need the space I can convert on-the-fly to RAID5. Not sure which features you are talking about when comparing the LSI to the PS5000E but besides the inability to create multiple arrays (which made sense to me from a controller design and big-picture perspective), I didn't find anything yet that I'd consider missing. Then again, I am not a storage expert by a long shot. The PS5000E is the iSCSI SAN for Dummies, works for me.

From my call today I also gathered that they are about to release new firmware to add RAID6 support.