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A real answer, though. Yes, there's a potential for latency or a performance hit from running your storage in a VT-d passthrough. But think about the practical aspects. Your system isn't going to be IOPS-bound in the first place. There are several levels of abstraction in this storage, and the fact that you're using VMs at all indicates that you're okay ...


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I don't recommend this type of passthrough setup anymore. It's a lose-lose on most counts, especially with reliability and performance. It can certainly be done, but the safest solution (especially with a hypervisor like ESXi) is to just use a supported RAID controller and local storage. If you want ZFS storage, build a standalone ZFS storage system.


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"t" == Terabytes. Move the decimal three places to the right, and you have 12GB.


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I received an answer from microsoft support which sort of makes sense. Anyway for future searches: No matter what the platform, the editions (not Web/Biz) provides capacity to ensure the DTU and response constraints as specified by https://azure.microsoft.com/en-us/documentation/articles/sql-database-benchmark-overview/#metrics (look at the ...


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Running PHP is expensive, in terms of CPU usage and RAM. Any time you can avoid invoking the PHP interpreter, you should. Caching is the primary way you do this, so long as the content isn't custom generated for every user. My little AWS t2.micro can serve around 2500 pages per second from its Nginx cache, but about 20 pages per second if PHP (HHVM) has to ...


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I would start with updating all firmware versions to the latest available, including the BIOS, iDRAC/Lifecycle Controller. This is more likely an issue with the power usage & performance settings in the BIOS though. Check out the Performance and Power Tuning doc for Dell 12th gen servers for details.


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I have 2 Win2K12-R2 T320's with same hardware, firmware and drivers. Yesterday one became painfully slow - no Windows updates installed in weeks. After running a DSET with no hardware errors: Dell tech recommended Going into the BIOS on the T320, go into System Profile Settings and change 'Performance per Watt' to 'Performance' Rebooted and server is ...


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It turns out the difference in response length is a methodological one. I didn't notice the Apache server was returning all 301 codes during this test, because the URLs were being re-written. I had to change the server URL and path to exactly match what the re-write rules enforce. After that, the content lengths matched up perfectly, and the Apache server ...


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It's possible to set on the kernel command line with e.g. elevator=deadline. I don't know for sure, but I consider it very unlikely that the default changed between 573.3.1 and 573.8.1 of Red Hat's 2.6.32 kernel. You can inspect your kernel command line by reading /proc/cmdline.


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HTTPS does slow your website down despite all claims to the contrary. This is because the client and server need to negotiate the SSL/TLS ciphers before it can start. However after that, the slowdown is negligible for most sites, and there are massive benefits to SSL. Additionally the default is http, so someone entering that for a https-only site will need ...


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You could enable HTTP/2, which will reduce the number of connections for compatible browsers, reducing page load time. This won't reduce latency for that connection though. Demo here. See also this question - latency is key in this situation. I ran a speed test against my https server in Sydney, Australia. Testing from another Sydney server the SSL ...


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As user the-wabbit suggests, there is request-merging going on. You can see that in the column avgrq-sz, the average request size - which shows a significant increase. Now 'await' is the time spent in the queue plus the time spent servicing those requests. If a small request, let's call it 'x', is merged with a couple of other requests (y and z, issued ...


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a. Have you check wait state of the running query ? Select * from sys.sysprocesses will do b. is there any resource governor in place ? c. have you use recompile hint to test it ? d. have you check the query plan ? e. have you tried to force the plan to run in paralel mode using dbcc cpuweight ? f. have you update the statistics of the tables?


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Even though this might be a bit late, you may try what I did: remove all mss, mtu, etc related options do a port scan at your institution and selected a UDP port, generally 53 GRE /123 NDP ports should be open: Add these lines to your server config (ref here) #possible bandwidth increase sndbuf 393216 rcvbuf 393216 push "sndbuf 393216" push "rcvbuf ...


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There's quite a few things to consider, because frames are not consistent in size, they can vary from 84 bytes to 1500~ Therefore you can't do a bits per second to packets per second conversion unless you assume all packets are the maximum size or do an average based on a sample. This article might help: ...


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Finally, I've managed to resolve it. In bug of 5.6.10 version I've found a solution: to comment line table_definition_cache = 1K Although I have version 5.6.27 it works greatly. Now MySql consumes less than 70MB.


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The answer is the dreaded "it depends." SQL Server performance is based on many things, but the biggest things are usually memory and disk I/O. SQL likes to put as much of the database as possible into memory. You didn't say how big the databases are, nor how busy. If they're two 50 MB databases that get a couple of queries a day, put them anywhere ...


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Use the 10 Gb/s link. Otherwise you restrict the VMs to 1 Gb/s when communicating with multiple clients or with other VMs (communication to other VMs should be through the virtual switch and not the physical NIC). If your network card supports it, use VMQ and / or SR-IOV. Ideally you should create an SR-IOV virtual NIC inside every VM. Most cards should be ...


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1 x 10Gb link for performance. Otherwise if a single server needs to use 1.1Gbs to another server it can't because most load balancing systems use destination MAC or IP (Which would be the same). This also eliminates issues where links are busier then other links because of the same fact, if the hash works out to be on the same link they end up on the same ...



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