Questions tagged [sas]

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 workstations, and it uses the standard SCSI command set.

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Are SSD drives as reliable as mechanical drives (2013)?

SSD drives have been around for several years now. But the issue of reliability still comes up. I guess this is a follow up from this question posted 4 years ago, and last updated in 2011. It's now ...
hookenz's user avatar
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110 votes
8 answers
23k 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 our ...
Stu Thompson's user avatar
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47 votes
3 answers
53k 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?
username's user avatar
  • 4,785
39 votes
7 answers
65k 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 ...
cnst's user avatar
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30 votes
2 answers
16k 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 Enterprise Storage so expensive?. My question is specifically about SAS drive enclosures, and justifying their expense. ...
Sam Elstob's user avatar
26 votes
2 answers
64k 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 ...
Damainman's user avatar
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24 votes
4 answers
74k 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 ...
dave's user avatar
  • 343
21 votes
2 answers
1k 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 ...
Peter Rowell's user avatar
18 votes
3 answers
17k 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.) ...
TomTom's user avatar
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16 votes
3 answers
77k 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 ...
Dai's user avatar
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15 votes
3 answers
55k 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 ...
flooble's user avatar
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15 votes
6 answers
20k 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 ...
boatcoder's user avatar
  • 548
13 votes
3 answers
23k views

So you really can push a SATA2 disk into a SAS backplane?

There's only one SAS, right? Serial attached SCSI? The female connectors: SATA2 looks like: ------------| |------- And SAS looks : ------------+-+------- For me, the SATA2 male connector looks ...
isync's user avatar
  • 701
13 votes
2 answers
32k 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 can'...
Chad Grant's user avatar
13 votes
6 answers
13k 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 SATA-to-...
korkman's user avatar
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13 votes
7 answers
34k 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, I'...
Earlz's user avatar
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12 votes
3 answers
99k views

HDD: performance differences between 7.2k SATA and 15k SAS

What is the rule of thumb in performance characteristics and differences between 7200rpm (SATA/SAS) and 15000rpm (SAS) hard disc drives of the same generation?
cnst's user avatar
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10 votes
1 answer
4k 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* ...
user avatar
9 votes
5 answers
12k 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 ...
SyRenity's user avatar
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9 votes
5 answers
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Can we upgrade Dell's basic Server R240 (which still uses HDD 7200RPM) to an SSD?

Today I was shopping for the most basic dell rack server which is the R240. Ironically, they are still using HDD 7200 RPM, with no option for SSD in their selection; and we're approaching 2020! ...
user1034912's user avatar
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9 votes
3 answers
32k 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 ...
katie's user avatar
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9 votes
2 answers
21k 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 ...
sbrattla's user avatar
  • 1,598
8 votes
8 answers
18k 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 ...
Anthony's user avatar
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8 votes
4 answers
18k 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 ...
growse's user avatar
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8 votes
3 answers
43k views

Can SAS drives be used with SATA controllers?

Can I buy SAS drives on my SATA Controller? What is the compatibility and restrictions about mixing these?
Jason's user avatar
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8 votes
2 answers
625 views

Storage server - Swapping SAS HBA card for a different model

TL;DR Server's original SAS HBA (PCIe card) does not support transparent passthrough, which is desired, as I want the OS to manage the disks (ZFS). At my company, we have an Intel SSR212MC2 server (...
Nubarke's user avatar
  • 210
8 votes
2 answers
1k 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 ...
carlpett's user avatar
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7 votes
5 answers
35k views

Will any SAS drive work in a Dell PowerEdge server?

If I bought a Dell 2950 or 2650, for example, and it has no drives in it (from say an auction). Will any SAS drive I get work in it? I ask because they vary so much in price. Some drives are $150 ...
johnny's user avatar
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7 votes
3 answers
15k views

SAS / SATA max number of connected disks vs performance

I would like to understand following things: When I have a motherboard with SATA 6Gb/s and 8 ports, does it mean that every single port is able to provide 6Gb/s speed to disk that is connected over ...
Petr's user avatar
  • 324
7 votes
5 answers
2k 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 ...
EricEE's user avatar
  • 73
7 votes
3 answers
6k views

SAS Expander backplane performance drops when more than 8 drives are active?

We are using an LSI 9211-8i raid controller (flashed in IT mode) in a PCI-e 2.0 x8 slot. It's connected to a supermicro SAS 836EL1 backplane with 1 SFF-8087 cable. We have 16 drives installed. When ...
Jorne's user avatar
  • 123
7 votes
5 answers
8k 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 ...
Jacob Groundwater's user avatar
7 votes
3 answers
2k views

3Gbps SSDs in RAID1 VS 6Gbps SAS Drives in RAID1 - Performance Difference?

I have bought two Intel DC S4500 480 SSDs (comes with 5 year warranty) to use with a HP G7 DL360 1U Server in RAID1. Unfortunately after purchasing the disks, I figured out that the integrated P410i ...
Tonmoy's user avatar
  • 235
7 votes
1 answer
7k views

How do you connect more than 4 drives to a LSI 9361-4i MegaRAID controller?

I’m fairly new to proper hardware RAID having only used it in pre-built server machines before, but on the recommendation of some friends who work for datacentres I’ve bought an LSI 9361-4i MegaRAID ...
Benjamin Nolan's user avatar
7 votes
3 answers
44k views

ProLiant DL380p not recognising HP hard drives on boot

I have two ProLiant DL380p rack mounted small factor servers. I have installed the following drives onto both servers: 1x 240GB SSD drive (Crucial NOT HP branded) 2.5" SATA 7.2k rpm 1TB (HP-branded) ...
tommed's user avatar
  • 299
7 votes
1 answer
10k 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 ...
longneck's user avatar
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7 votes
2 answers
9k 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 ...
Andy Shinn's user avatar
  • 4,271
6 votes
4 answers
17k 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?
Jé Queue's user avatar
  • 363
6 votes
8 answers
3k 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 ...
Aleksandr Levchuk's user avatar
6 votes
2 answers
3k views

HP ProLiant DL380 G7 LFF - Is every SAS HDD compatible?

I am just starting to get into server hardware, so please bear with me. I bought a HP ProLiant DL380 Generation 7 with a LFF drive cage and I do not know which SAS drives are actually compatible. ...
Sandrogo's user avatar
  • 163
6 votes
2 answers
23k 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 ...
Garry Harthill's user avatar
6 votes
3 answers
4k 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. ...
Eric C. Singer's user avatar
6 votes
1 answer
2k views

How to connect two Dell storage arrays to a to a Dell Poweredge server (daisy chain vs direct)?

I purchased two Dell MD1000 storage arrays together with a Dell Poweredge 1950 server and need help setting them up (I am a complete novice to SAN/iSCSI). The Poweredge server has two SAS SFF-8470 ...
Greg's user avatar
  • 1,677
6 votes
1 answer
18k views

What is a maximum useful length of a SATA/SAS cable?

The server in question is DELL PowerEDGE SC1435. I am thinking about buying a LSI 1068e based card with two internal SFF-8087 ports. I intend to use the machine with external multiple hard disk ...
SaleB's user avatar
  • 63
6 votes
2 answers
17k 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 ...
Ryan's user avatar
  • 177
5 votes
5 answers
5k views

Would using SAS disks instead of SATA disks make sense over NFS for a VMWare datastore?

We are deciding whether to use SATA or SAS aggregates on our Filer for our VMWare datastore. We will be using NFS to connect the VMWare hosts to storage. Doesn't seem to make sense to use SAS disks ...
Belmin Fernandez's user avatar
5 votes
4 answers
7k 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”. ...
Nate's user avatar
  • 2,366
5 votes
3 answers
14k 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 ...
gravyface's user avatar
  • 14k
5 votes
2 answers
3k 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 ...
Bertrand SCHITS's user avatar
5 votes
1 answer
4k views

Recovering data from a failed SAS drive? (RAID0...yes, I know)

We have a HP DL360 server with a P400 controller, which has two 72GB 10K SAS drives in a RAID 0 configuration (yes, I know...RAID 0). The HP Model number for the drives is DG072A8B54 Recently, one ...
victorhooi's user avatar

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