19
votes
Accepted
SAS / SATA max number of connected disks vs performance
SATA/SAS are not like hubs, rather they work much like a network switch. This means that a single SATA/SAS port provides the entire advertised bandwidth, independently from the other ports.
In other ...
- 49.1k
11
votes
Accepted
How can I connect a SAS drive to USB?
Such device finally exist CXRT SAS to USB adapter CXRT-USB3. You can find it on Amazon, eBay and couple other places. There are 2 downsides in my opinion. It’s almost 100 times more expensive than ...
- 126
11
votes
Accepted
HP ProLiant DL380 G7 LFF - Is every SAS HDD compatible?
HPE HDDs will have custom firmware so "ordinary" HDDs even from OE HDD vendor will work just fine (and you'll even keep your warranty, please see my link below) but you won't have special features ...
- 13.8k
11
votes
Accepted
Can we upgrade Dell's basic Server R240 (which still uses HDD 7200RPM) to an SSD?
On Dell's R210, R220 and T130 I've successfully used Sandisk's consumer grade SSDs for years. I've done this with PERC's H410 and H710 controllers.
It will be a matter of controller and controller's ...
- 1,709
9
votes
Can we upgrade Dell's basic Server R240 (which still uses HDD 7200RPM) to an SSD?
Yes, you can swap HDDs <-> SSDs the way you want. Moreover, it's OK to use non-Dell branded SSDs inside Dell servers, you won't receive support (of course!) and some functions won't work like LEDs, ...
- 13.8k
9
votes
NFS SATA vs SAS for VMware datastore?
You missed two things:
15k (and partly 10k) drives were almost killed by entreprise SATA SSD;
HDD IOPs are strongly limited by random access, rather than interface bandwidth.
Modern high perf ...
- 49.1k
8
votes
Accepted
hp proliant not recognizing emc sas drives
You can make this work with some effort. Normally, I'd be all like, "Use HP drives", but the fact that you're using a G7 ProLiant means that many of the firmware restrictions don't apply from either ...
- 198k
8
votes
Accepted
3Gbps SSDs in RAID1 VS 6Gbps SAS Drives in RAID1 - Performance Difference?
In most scenarios, including common virtualization workloads, the SSDs will outperform the HDD drives due to lower latency and higher IOPS.
The link speed is a lot less relevant than latency or IOPS ...
- 971
8
votes
Difference between hard drives
Yes, that is correct. There are multiple reasons for this:
SAS drives are sold less, leading to scale effects.
They are actually more reliable
These 1.2 GB 2.5" are 10k RPM drives, so they are ...
- 99.1k
8
votes
Accepted
How much PCI-E bandwidth can my SAS HDD array make use of?
Ah, did you ever bother to get away from the theoretical numbers? You state so nicely...
18 x SAS3 maximum at peak: (1.2 x 18) = 21.6 GB/sec
Yeah. Now show me a single hard disc (and you talk about ...
- 51.8k
7
votes
Performance Difference SAS vs. SATA?
This is a late answer, but I would like to add my opinion.
From a pure speed standpoint, a nearline drive (as the ones OP considered) will performs practically the same both using the SATA interface ...
- 49.1k
6
votes
How can I connect a SAS drive to USB?
While we can all appreciate the occasional advice on backup strategies and their importance, there are things that even Tivoli won't help you with, so to answer the actual question, in short:
To ...
- 4,426
6
votes
Erasing Server RAID Hard disks (SAS and SATA) for decomissioning
Finally I got the solution.
According to Fujitsu "LSI Logic MegaRAID SCSI WebBIOS Configuration Utility" User's guide, virtual disk initialization can be a good start to remove data from the disk:
...
- 9,061
6
votes
Accepted
3ware 9650se not recognizing SAS drives, what else should I check?
Unfortunately, 9650se is SATA controller and therefore it doesn't support SAS drives.
- 4,564
6
votes
Accepted
How to connect two Dell storage arrays to a to a Dell Poweredge server (daisy chain vs direct)?
You can stack the MD unit that way; (In the image its 3 MD, but you can see how)
For your openmanage question, yes, it can be used remotly, but be sure to set the routing correctly in the management ...
- 16.9k
5
votes
hp proliant not recognizing emc sas drives
is there something we are missing or is this hopeless?
They're not supported, HP puts a specific firmware on their disks that provides a lot of additional diagnostic data over an off-the-shelf disk. ...
- 102k
5
votes
Accepted
LSI 9211-8i won't boot in KVM
In case anybody stumbles upon this: the solution to such a problem is to set rombar=0 in the PCI passthrough in your vm.conf:
hostpci0: 06:00.0,rombar=0
(whereas 06:00.0 is the relevant slot you want ...
- 66
5
votes
Accepted
Accidental SAS cable removal
TL;DR: If you accidentally removed a SAS cable from your server then install storcli and run
storecli /call show
note the correct controller and enclosure and the nrun
#!/bin/bash
# Use your ...
- 265
5
votes
Accepted
what is the difference between a sas controller and a sas raid controller?
A SAS controller (HBA, Host Bus Adapter) on its own has no RAID ability. It just presents however many disks are plugged in to the underlying operating system, and it's the OS's job to figure out what ...
- 69k
5
votes
Accepted
SAS RAID5 Disk failure, replacement enclosure not matching
You can use the old enclosure and put new disk in to that enclosure, i had done same for my Dell R620
Ensure you not misplace any screws and fit all screws
- 436
5
votes
SAS RAID5 Disk failure, replacement enclosure not matching
These are the two different drive tray/carrier/sled designs. The Gen8+ Smart Carrier is on the left. The G7 style is on the right.
You can swap the bare drive into the Gen8 carrier and be fine.
- 198k
5
votes
How to use 12 HDDs with the Supermicro BPN-SAS3-826EL1 backplane?
If you have the -EL1 backplane, you should be able to see all 12 drives, even with a single cable from the RAID card to the expander backplane. If you don't, something's wrong with the backplane or ...
5
votes
SAS Drive Upgrade
Do backup of the whole RAID1 volume.
Replace drives and create a new RAID1
Restore backup to "new" RAID1 volume
- 9,066
4
votes
Use of 2.5" Laptop Drives in a Server?
Apparently everyone saying to use enterprise drives...just because...are mistaken.
There are several articles from companies that have actually done this vs just making stuff up.
In short: ...
- 51
4
votes
Anyone seen a meaningful SAS vs SATA comparison/benchmark?
So much misinformation here!
I can't imagine a meaningful benchmark between SAS and SATA and I wouldn't bother looking for one. This is like benchmarking a six passenger minivan versus high-speed ...
- 41
4
votes
ZFS best practices with hardware RAID
Everybody tells that ZFS on top of RAID is a bad idea without even providing a link. But the developers of ZFS - Sun Microsystems even recommend to run ZFS on top of HW RAID as well as on ZFS mirrored ...
- 317
4
votes
Accepted
What's the top normal S.M.A.R.T. temperature for HGST Helium Ultrastar 8TB 7200 RPM SAS 12Gb/s enterprise drives?
Anything under 55-60 C should be ok. Anyway, what is really dangerous for a mechanical drive are repeated thermal excursions, where the drive become hot and rapidly cools. Equally dangerous are ...
- 49.1k
4
votes
How can 8 SAS lanes support 1024 disks?
This is due to SAS support for expanders.
Basically, an expander is akin to a port multiplier / network switch, where a single upstream SAS connection can be expanded in up to 255 different downstream ...
- 49.1k
4
votes
hp proliant not recognizing emc sas drives
Having worked with HP servers since G2 days I just thought I'd throw my two pence worth in.
I have done a lot of unusual things with HP servers for Dev and training purposes. A HP SAS crontroller (...
- 41
4
votes
Accepted
Poor performance with Linux software raid-10
Edit:
Your dd oflag=direct observations might be due to power management issues. Use PowerTOP to see if your CPU's C-states are switched too often above C1 under write load. If they are, try tweaking ...
- 40.8k
Only top scored, non community-wiki answers of a minimum length are eligible