Serial Attached SCSI (SAS) is a computer bus used to move data to and from computer storage devices such as hard drives and tape drives. SAS depends on a point-to-point serial protocol that replaces the parallel SCSI bus technology that first appeared in the mid 1980s in data centers and ...

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63
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8answers
6k views

How can a single disk in a hardware SATA RAID-10 array bring the entire array to a screeching halt?

Prelude: I'm a code-monkey that's increasingly taken on SysAdmin duties for my small company. My code is our product, and increasingly we provide the same app as SaaS. About 18 months ago I moved ...
40
votes
3answers
47k views

What are the merits of SAS vs SATA drives? [closed]

What are the merits of buying SAS drives over SATA drives, or vice versa?
27
votes
2answers
6k views

Why are enterprise SAS disk enclosures seemingly so expensive?

I will begin by stating that I do not believe this is a duplicate of Why is business-class storage so expensive?. My question is specifically about SAS drive enclosures, and justifying their expense. ...
26
votes
10answers
21k views

Cheapest way to connect 20-24 Sata II HDDs in a budget storage server? [closed]

I need to assemble a high density storage server for as cheap as possible. It's been a while for me and the last systems I integrated didn't even have Sata yet... During my Research I of course ...
14
votes
1answer
468 views

Sanity check on 40TB server configuration

I've got 40 years in computing, but I've never had to build a server quite like this one, so this might be a n00b question. I have a client that is going to offer ultra-high def music files for ...
13
votes
4answers
13k views

Anyone seen a meaningful SAS vs SATA comparison/benchmark?

I hear lots about SATA being slower than SAS but I've only found 1 decent benchmark. http://blog.whitesites.com/SAS-RAID-0-VS-SCSI-RAID-0-VS-SATA-Benchmarks__633689244191943184_blog.htm In this, SAS ...
11
votes
5answers
2k views

ZFS best practices with hardware RAID

If one happens to have some server-grade hardware at ones disposal, is it ever advisable to run ZFS on top of a hardware-based RAID1 or some such? Should one turn off the hardware-based RAID, and run ...
10
votes
4answers
3k views

Any experience with SATA SAS Interposer Cards?

Driven by the current price difference between SATA and SAS disks on one side and the potentially bad behaviour of SATA disks in bigger storage arrays on the other side, I have found so-called ...
10
votes
1answer
683 views

Performance Difference SAS vs. SATA?

Can not find that anywhere it seems. What is the expected performance difference in a storage backend scenario that is heavily parallellized in access (like a SAN, Virtualization host storage etc.) ...
9
votes
3answers
28k views

SAS vs. Nearline/MDL SAS - What is the difference?

As subject I guess, looking at SAN's and most vendors offer 10k or 15k "proper" SAS drives, many also offer 7.2k MDL/Nearline SAS drives. Does anyone have an authoritative explanation of the ...
9
votes
7answers
23k views

SCSI vs SATA? Is SCSI “actually” better? [closed]

Well, I was talking with a guy about servers the other day. I was a bit shocked whenever I asked him if there was any significant difference between SCSI and SATA and why he always uses SCSI. (note, ...
9
votes
1answer
2k views

Improving SAS multipath to JBOD performance on Linux

I'm trying to optimize a storage setup on some Sun hardware with Linux. Any thoughts would be greatly appreciated. We have the following hardware: Sun Blade X6270 2* LSISAS1068E SAS controllers 2* ...
8
votes
2answers
419 views

Are branded backplanes useable without specific controllers?

I can't find a disk enclosure which I like, so I'm going to build a custom one (if nothing else, that'll teach me to be picky...). I've got a few HP SAS backplanes lying about, but I'm wondering if ...
7
votes
5answers
786 views

ML350 G5 - upgrade hot swap drives to 6 Gb/s?

I support a non profit. They got an ML350 G5 donated to them and I immediately put it to good use for them :) It came with four HP 300GB 15K SAS drives - and of course, they have all now failed. I ...
7
votes
2answers
14k views

How can I connect a SAS drive to USB?

I have a Dell T710 with Seagate Cheetah 15k.7 SAS disks. If the T710 motherboard dies, I'll need to resort to one of my nightly off-site backups and salvage the journal/logfile from the SAS disk to ...
7
votes
2answers
4k views

LSI 9285-8e and Supermicro SC837E26-RJBOD1 duplicate enclosure ID and slot numbers

I am working with 2 x Supermicro SC837E26-RJBOD1 chassis connected to a single LSI 9285-8e card in a Supermicro 1U host. There are 28 drives in each chassis for a total of 56 drives in 28 RAID1 ...
6
votes
3answers
14k views

SAS vs Near-line SAS vs SATA

I'm unsure about the differences in these storage interfaces. My Dell servers all have SAS RAID controllers in them and they seem to be cross-compatible to an extent. The Ultra-320 SCSI RAID ...
6
votes
5answers
8k views

SAS or SATA for 3 TB drives?

We are looking to purchase new 3 TB enterprise-grade drives and can buy either SAS or SATA models. AFAIK, SAS generally gives better performance than SATA, but searching for benchmarks I found ...
6
votes
8answers
2k views

What are SAS external storage options (Promise, Infortrend, SuperMircro, …)?

We are looking for a ~32T external storage solution for two 48-core AMD servers. These will be used for a small Linux OpenVZ cloud for CPU intensive web-servers and data warehousing. Dual path with ...
6
votes
1answer
5k views

How exactly does a SAS SFF-8087 breakout cable work? + RAID/connection questions

Please let me know if my question does not makes any sense as I am not sure if I am interpreting it correctly from my thoughts due to my lack of technical knowledge on this. If I am using a ...
6
votes
3answers
992 views

Dell MD1000 and an x4 SAS connector throughput / layout

I'm trying to get my head around how a multi lane x4 SAS connector works in a DAS system such as the Dell MD1000. I understand that each lane is 3Gbps, and that multiple hard drives can share a lane. ...
6
votes
1answer
2k views

replace controller, add second controller, or use expander?

I have a Proliant DL380 G6 that I am re-purposing as a Hyper-V host for a new, off-site data center that will host our DR services. The server currently has a P410i controller with the 512MB BBWC ...
6
votes
1answer
3k views

Do SAS expanders work transparently with SAS controllers?

I'm new to SAS expanders and I'm trying to get things right. I understand that SAS expanders, when used with SAS controllers which supports expanders, allows you to utilise the full capacity of ...
5
votes
4answers
10k views

Performance differences between 2.5“ vs. 3.5” SAS

What real performance gains/losses are there on 2.5" vs. 3.5" 15k SAS drives. Are folks really seeing seek differences, &c?
5
votes
2answers
622 views

Nearline SAS on SATA controllers

I know that SAS drives cannot operate on a SATA controller. I know that SATA drives can operate on a SAS controller. But can Near-Line SAS drives, being SATA drives with a SAS controller, be used on ...
5
votes
2answers
9k views

What is a RAID Controller's Sideband Cable used for?

I have some Adaptec SAS raid controllers and the fanout cable comes with an extra cable called a SideBand but I am curious what it does? I know it plugs into the backplane, but other than that I ...
5
votes
1answer
183 views

26 hard drive limit on x86 servers, IBM x3650, Dell PE 2950, Dell PE 2850, where is my limitation?

This is in regard to mass HDD wiping/testing. The software I use, WipeDrive Pro 5 and 7, both fall victim. I originally thought it was a limitation of the software, but after speaking with the ...
5
votes
1answer
8k views

Are 6Gb/s SAS drives compatible with 3Gb/s SAS interfaces?

Are SAS 3Gb/s controllers (SAS1) forward compatible with newer SAS2 drives specified at 6Gb/s? The controller I have in mind is an LSI SAS1064. I know that SAS2 controllers are backwards compatible ...
4
votes
6answers
4k views

Use of 2.5" Laptop Drives in a Server?

We're acquiring several 1U servers with (8) 2.5" drive slots. Although we can use either SATA or SAS, there is a large price variance as soon as you order 16 or 24 of these drives, so we are looking ...
4
votes
5answers
2k views

How should I sanitize a SAS drive that I removed from a RAID 5 Array?

I had a disk experience a predictive failure. As a result, I removed the drive and replaced it. Now that I have the drive removed, I would like to sanitize it. What is the easiest way to go about ...
4
votes
3answers
1k views

Why do servers have SAS instead of SSDs? [closed]

I was wondering why do servers still come with SAS disks instead of SSD disks? I know that SAS are faster than normal hard drives but they are still much slower than SSDs. I think they are more ...
4
votes
4answers
2k views

Is it normal for a SAS drive to have a few bad blocks, or should I replace my drive ASAP?

I have a drive—part of a RAID 1 mirror—that has two bad blocks. Adaptec Storage Manger e-mailed me when it detected the blocks. It shows 4 medium errors for that drive, but state is still “optimal”. ...
4
votes
2answers
1k views

SAS enclosure doesn't restart - MSA60

I just inherited a HP StorageWorks MSA60 (this is a direct-attach SAS enclosure). I had to move it to another shelf so I turned off the computer which was using it. I also pulled the 2 power cords off ...
4
votes
3answers
558 views

What type of SAS/SATA cables do Dell SAS6/iR and SAS5/iR controller cards use?

I'm considering buying a bunch of these to upgrade our servers at work (with SATA drives, not true SAS). We are out of ports to plug disks into, and these cards are decently supported and cheap. The ...
4
votes
2answers
2k views

Beginner SAS and server questions

I am a c++ programmer and database administrator looking to expand my knowledge of server administration and maintenance. I have read the Wikipedia pages and several other documents I found by ...
4
votes
4answers
2k views

SAS Expanders for DIY JBOD Arrays

I am researching making a DIY SAS array much like the Dell MD1000. My understanding is that these devices do not contain a RAID controller, instead they present all the drives on in SAS domain to the ...
4
votes
1answer
6k views

Mixing dual and single port SAS disks

I have a HP DL380 G5 with 8x146GB single port SAS SSF disks (DG146ABAB4). A couple of them have failed and I can't find any new single port disks anymore. They all seem to be dual port. I'm wondering ...
4
votes
2answers
197 views

Difference between SAS multilane, direct-attached HDD and expander backplane?

What's the difference between multilane, direct-attached HDD and expander for SAS backplanes? Supermicro chassis description page Direct attached HDD backplane (TQ version), multilane ...
4
votes
2answers
181 views

SAS internal cable compatability

In the office, we've elected to whitebox go with a commodity approach to a certain class of server we'll eventually need a lot of. It's time to consider picking up a few more. It has been a year since ...
3
votes
4answers
4k views

HP D2700 enclosure and SSDs. Will any SSD work?

I've got an HP D2700 enclosure that I'm looking to shove some 2.5" SSD drives in. Looking at the prices of HP's SSD drives vs something like an Intel 710 and even something less 'enterprisey', there's ...
3
votes
6answers
262 views

Way to inexpensively temporarily increase storage on production servers?

We have a set of 6 servers in production for storing some massive databases. Right now they have 280Gb of disk space striped and mirrored across 15K SCSI Drives, our existing database fills them to ...
3
votes
3answers
1k views

Are all SAS drives hot-swappable?

Can get a 300GB Cheetah 15K SAS 3.5 disk for quite a bit cheaper through another supplier vs. Dell's out-of-warranty depot (for an aging PowerEdge server). Specs are identical, wondering if there's ...
3
votes
3answers
269 views

HP SAS hdd in non-HP server

I wonder if I could re-use some HP SAS drive in a non-HP server. Description: 146GB 2.5" Serial Attached SCSI (SAS) SFF 3G Single Port Hot-Plug 10K HDD Option Part# 431958-B21 Spare Part# 432320-001 ...
3
votes
1answer
338 views

Connecting our first tape drive (SAS) to SATA bus

Our small team is considering buying our first tape drive for backups. However, we are still lacking serious enterprise-grade servers and have to rely temporarily on SATA drives in our rigs. Cost ...
3
votes
1answer
327 views

Mixing 15K rpm SAS with 7.2K rpm SATA on Dell PowerEdge R610

Is it possible to mix 15K rpm SAS with 7.2K rpm SATA on Dell PowerEdge R610 on the same RAID configuration (Raid 5)? Is the SAS' speed going to drop to follow the lowest speed (the SATA speed)? and ...
3
votes
1answer
869 views

Can I mix SAS and SATA2 drives on one controller?

I've read here that I can't mix SAS and SATA2 drives on the same controller - is that really true? I understand I shouldn't mix on the same channel, but the same card!? For example, when I plug my ...
3
votes
1answer
222 views

Are PCIe v2 RAID controllers backward compatible with PCIe V1?

I am looking to add a PCIe V.2 RAID controller (LSI SAS 9280-4i4e) to an older Intel server (SR2500) which has PCIe V.1 slots. Does anyone have any experience with using RAID controllers designed for ...
3
votes
1answer
117 views

Are FC and SAS DAS devices standard enough?

Before I ask my questions, here is some background info that may or may not be useful: For the first time I find myself needing a DAS solution. My priority is data through-put in a single direction. ...
3
votes
4answers
663 views

ZFS server hardware questions

I'm a photographer by trade and I've yet to find a method I'm happy with for archiving my work. Currently I'm looking at building a NAS server using OpenSolaris, so I can use ZFS. That way I can take ...
3
votes
2answers
3k views

Solaris Multipathed I/O - Physically Removing a Disk

I am a Solaris newbie. I have a Solaris 10u8 machine that is running an attached J4400 and some internal drives. We're using multipathed SAS I/O (stmsboot; mpathadm), so the device mount points have ...