Internal Raid
Floriana Grundy
The ThinkSystem RAID 940 family of PCIe 4.0 12 Gbps SAS RAID controllers are high-performance RAID-on-chip (ROC) adapters for connectivity to drives internal to the server. These adapters support RAID levels 0, 1, 10, 5, 50, 6 and 60, and include an extensive list of RAS and management features.
This product guide provides essential presales information to understand the ThinkSystem RAID 940-8i, 16i and 32i adapters and their key features, specifications, and compatibility. This guide is intended for technical specialists, sales specialists, sales engineers, IT architects, and other IT professionals who want to learn more about the adapters and consider their use in IT solutions.
The ThinkSystem RAID 940 family of PCIe 4.0 12 Gbps SAS RAID controllers are high-performance RAID-on-chip (ROC) server adapters for connectivity to drives internal to the server. These adapters support RAID levels 0, 1, 10, 5, 50, 6 and 60, and include an extensive list of RAS and management features.
The RAID 940 Series adapters all have a PCIe 4.0 host interface which doubles the bandwidth between the server and the adapter, compared to the previous generation RAID 930 adapters. This improves overall performance of the storage subsystem by supporting up to 3 million IOPS (JBOD mode) and up to 3 million IOPS in RAID (random reads).
RAID on Chip-based controllers such as the RAID 940 adapters have a dedicated processor that offloads all RAID functions from the server's CPU. With hardware acceleration for RAID 5 and 6 operations plus up to 8 GB dedicated memory for caching, the 940-8i, 16i and 32i offer the ultimate performance for ThinkSystem servers.
The table includes feature codes for the RAID 940 adapters to be ordered with the Tri-Mode feature enabled. Tri-Mode enables the support of SAS, SATA and NVMe drives to be connected to the adapter, as described in the Features section.
For example if a 3TB drive has 3 platters. Why cant there be 3 heads and on onboard RAID controller IN the drive case with error correction, so we get 1TB or 2TB of effective storage space (less space), but now the drive itself is 2 or 3 times more reliable
No one is going to do this because we already have RAID. RAID is preferable to RAIP (Redundant Array of Independent Platters) because you can replace the failed drive, you can scale as you need and you tune your RAID type for your purposes.
I think that there are few mechanical devices with better reliability than hard drives. HD manufactures deserve some serious kudos. What they do is truly amazing. HDs are constantly improving and their reliability is truly amazing.
Doing internal drive parity would actually decrease drive reliability by increasing wear and tear for the same workload and would dramatically slow the drive (just as parity RAID does today.) Plus, if implemented like RAID 5 is today, it would introduce all of the same weird risks that parity RAID has.
I am having some problems searching and sorting data on my internal RAID drive. I have a Mac Pro tower (10.12.4) with five internal drives. One is a SATA SSD connected via PCIe as my boot disk (name: Server OS). The other four drives are in a software RAID 10 (name: Server RAID, set up by disk utility). Some time recently (within the last month, I believe, but I am not positive), I lost the ability to search for files on the Server RAID disk.
Basically, whenever I search within folders in the disk, I get this searching icon: But the window looks like this forever, and the search never turns up a single match. Something else I noticed is that anything that is on this disk and is tagged (using the color labels built in to macOS) does NOT turn up when I sort by the tagged colors in Finder. When I run this task in automator: I get this error:
Other tidbits: I am the only user and administrator of this computer. I have tried rebooting it and reinstalling macOS. I HAVE tried getting spotlight to reindex* (see note at bottom) but without success. Recently, I have (relatively recently) made the following changes to my system:
*Note regarding reindexing of Spotlight: To reindex Spotlight, I went to System Preferences -> Spotlight -> Privacy. I added the Server RAID disk to the list of things for spotlight to ignore, then quit System Preferences. I reopened System Preferences, and did the same thing in reverse. I monitored my CPU usage for about 3 minutes afterwards, and it didn't increase, making me think that spotlight actually DIDN'T reindex.
Finally, an answer! I contacted Apple Support with the problem soon after I made this post. Two weeks and many hours of phone and chat support later, we seem to have found an answer. The problem appears to have been with the indexing at the root level (which is why reindexing from System Preferences didn't work), likely caused by the macOS 10.12.4 software update. The solution was simple:
The ViconNet NVR Shadow is a high-capacity network video recorder that enables you to simultaneously capture, view and store high-quality, high resolution voice, video and data for a comprehensive security solution. It provides scalable, internal RAID 5 or 6 storage for medium and large-scale installations. The ViconNet NVR Shadow helps security organizations reduce system ownership costs, streamline operations and deliver more effective security.
Built for reliability, usability, and low cost of ownership
Proven in daily operation in thousands of customer installations worldwide, ViconNet NVRs feature an embedded operating system designed for enhanced security and superior reliability. The ViconNet video management software (VMS) that powers the ViconNet NVR Shadow, provides a standards-based open platform that allows integration with IP cameras, including megapixel cameras, encoders and IP edge devices from numerous, industry-leading manufacturers. The internal RAID 5 or 6 storage provides abundant capacity and the assurance that your data will always be secure and protected. The removable drive configuration (4-bay, 8-bay or 24-bay) makes it easy to hot-swap drives without having to remove the unit from the rack.
Powerful VMS Software
ViconNet VMS provides outstanding functionality and an intuitive interface for administrators, security managers and system operators anywhere on the network. Multi-site users, in particular, benefit from the efficiency of enterprise management options.
Scalability
The ViconNet NVR Shadow provides scalable, internal RAID 5 or 6 storage for medium and large-scale installations. The system is designed to scale to thousands of cameras with additional ViconNet NVRs, Kollector DVRs or any of the ViconNet VMS products.
1) is it even possible? I have been studying about raids for some time and didnt found why this shouldnt work (just that the slower hdd will be bottleneck, but I dont care about that) But than I read somewhere that internal hdd is "dynamic" and external not, so it cant be used for booting up system (I dont really what is this about)
2) Do the partitions in the raid need to be at the exactly the same place? I know they have to be the same size, but will it matter if I will make RAID from e.g. /dev/sda1 primary part. at the begining of disc and /dev/sdb5 logical part. at the end of disc (e.g. I would not do that, just because I also want to have my win partition on internal HDD, but I don't want to raid it too. It has about 20 GB just for games and I don't want to put it at the end of disc, because of disc head traveling, I will rather have static data (movies, music, images... ) at the end of disc (I tried it in VBox and it worked fine)
3) is there any difference between having one big raid partition with lvm on top of it vs having separated raid 1 for every partition? (will lvm adds to CPU usage? latency? will be many raid partitions a little safer than having one partition?)
I think it could theoretically be possible, but it's going to be horribly slow. If your machine can boot from USB, you should be able to boot from an external disk, but that can be thrown off by additional usb disks (that steal the disk label before it gets it).
It might be an issue if you have one single RAID partition and have bad sectors, but this is just a theory on my part.. I tend to make multiple smaller RAID partitions, as errors on that partition won't take out one half of your raid partition, just the part with errors.
RAID must not be used, no matter how say another thing, if your data is really important, RAID does not warranty data is correctly written to disks (it can not know if data on a sector is correct or has been altered, no checksum is calculated, no hash, etc).
Personally i am using RAID-0 with three disks (PATA about 28MiB/s and each SATA about 45MiB/s), so i get arround 105MiB/s (adding the PATA reaches the bottleneck since PCI-32 33MHz can not sustain the three HDDs bandwith 2xSATA+1xPATA plus all cards, and gain by adding PATA is only 15MiB/s, but all counts), also more, adding the PATA causes the SATAs to not be used at max bandwidth, so they work on relax, also the PATA works on relax way since bottleneck is at PCI bus, so the HDDs have some time to cold them selfes (something most people do not care about)... why i use so fast HDDs that they are doing nothing half of the time? just to not over heat them and no need to have them on refrigerated room! Also to enlarge their live really a lot!
Migrating to ZFS do not get things better? Oh, yes and no; since compresion is ON it gains a lot, now (with compressible data) i can sustain a near 105MiB/s (compressed data) and since compression is near 2.5:1 i can read/write real uncompressed data at more than 261MiB/s on best cases.
c80f0f1006