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  • Best Practices - updated: which domain types should be used to run applications

    - by jsavit
    This post is one of a series of "best practices" notes for Oracle VM Server for SPARC (formerly named Logical Domains). This is an updated and enlarged version of the post on this topic originally posted October 2012. One frequent question "what type of domain should I use to run applications?" There used to be a simple answer: "run applications in guest domains in almost all cases", but now there are more things to consider. Enhancements to Oracle VM Server for SPARC and introduction of systems like the current SPARC servers including the T4 and T5 systems, the Oracle SuperCluster T5-8 and Oracle SuperCluster M6-32 provide scale and performance much higher than the original servers that ran domains. Single-CPU performance, I/O capacity, memory sizes, are much larger now, and far more demanding applications are now being hosted in logical domains. The general advice continues to be "use guest domains in almost all cases", meaning, "use virtual I/O rather than physical I/O", unless there is a specific reason to use the other domain types. The sections below will discuss the criteria for choosing between domain types. Review: division of labor and types of domain Oracle VM Server for SPARC offloads management and I/O functionality from the hypervisor to domains (also called virtual machines), providing a modern alternative to older VM architectures that use a "thick", monolithic hypervisor. This permits a simpler hypervisor design, which enhances reliability, and security. It also reduces single points of failure by assigning responsibilities to multiple system components, further improving reliability and security. Oracle VM Server for SPARC defines the following types of domain, each with their own roles: Control domain - management control point for the server, runs the logical domain daemon and constraints engine, and is used to configure domains and manage resources. The control domain is the first domain to boot on a power-up, is always an I/O domain, and is usually a service domain as well. It doesn't have to be, but there's no reason to not leverage it for virtual I/O services. There is one control domain per T-series system, and one per Physical Domain (PDom) on an M5-32 or M6-32 system. M5 and M6 systems can be physically domained, with logical domains within the physical ones. I/O domain - a domain that has been assigned physical I/O devices. The devices may be one more more PCIe root complexes (in which case the domain is also called a root complex domain). The domain has native access to all the devices on the assigned PCIe buses. The devices can be any device type supported by Solaris on the hardware platform. a SR-IOV (Single-Root I/O Virtualization) function. SR-IOV lets a physical device (also called a physical function) or PF) be subdivided into multiple virtual functions (VFs) which can be individually assigned directly to domains. SR-IOV devices currently can be Ethernet or InfiniBand devices. direct I/O ownership of one or more PCI devices residing in a PCIe bus slot. The domain has direct access to the individual devices An I/O domain has native performance and functionality for the devices it owns, unmediated by any virtualization layer. It may also have virtual devices. Service domain - a domain that provides virtual network and disk devices to guest domains. The services are defined by commands that are run in the control domain. It usually is an I/O domain as well, in order for it to have devices to virtualize and serve out. Guest domain - a domain whose devices are all virtual rather than physical: virtual network and disk devices provided by one or more service domains. In common practice, this is where applications are run. Device considerations Consider the following when choosing between virtual devices and physical devices: Virtual devices provide the best flexibility - they can be dynamically added to and removed from a running domain, and you can have a large number of them up to a per-domain device limit. Virtual devices are compatible with live migration - domains that exclusively have virtual devices can be live migrated between servers supporting domains. On the other hand: Physical devices provide the best performance - in fact, native "bare metal" performance. Virtual devices approach physical device throughput and latency, especially with virtual network devices that can now saturate 10GbE links, but physical devices are still faster. Physical I/O devices do not add load to service domains - all the I/O goes directly from the I/O domain to the device, while virtual I/O goes through service domains, which must be provided sufficient CPU and memory capacity. Physical I/O devices can be other than network and disk - we virtualize network, disk, and serial console, but physical devices can be the wide range of attachable certified devices, including things like tape and CDROM/DVD devices. In some cases the lines are now blurred: virtual devices have better performance than previously: starting with Oracle VM Server for SPARC 3.1 there is near-native virtual network performance. There is more flexibility with physical devices than before: SR-IOV devices can now be dynamically reconfigured on domains. Tradeoffs one used to have to make are now relaxed: you can often have the flexibility of virtual I/O with performance that previously required physical I/O. You can have the performance and isolation of SR-IOV with the ability to dynamically reconfigure it, just like with virtual devices. Typical deployment A service domain is generally also an I/O domain: otherwise it wouldn't have access to physical device "backends" to offer to its clients. Similarly, an I/O domain is also typically a service domain in order to leverage the available PCI buses. Control domains must be I/O domains, because they boot up first on the server and require physical I/O. It's typical for the control domain to also be a service domain too so it doesn't "waste" the I/O resources it uses. A simple configuration consists of a control domain that is also the one I/O and service domain, and some number of guest domains using virtual I/O. In production, customers typically use multiple domains with I/O and service roles to eliminate single points of failure, as described in Availability Best Practices - Avoiding Single Points of Failure . Guest domains have virtual disk and virtual devices provisioned from more than one service domain, so failure of a service domain or I/O path or device does not result in an application outage. This also permits "rolling upgrades" in which service domains are upgraded one at a time while their guests continue to operate without disruption. (It should be noted that resiliency to I/O device failures can also be provided by the single control domain, using multi-path I/O) In this type of deployment, control, I/O, and service domains are used for virtualization infrastructure, while applications run in guest domains. Changing application deployment patterns The above model has been widely and successfully used, but more configuration options are available now. Servers got bigger than the original T2000 class machines with 2 I/O buses, so there is more I/O capacity that can be used for applications. Increased server capacity made it attractive to run more vertically-scaled applications, such as databases, with higher resource requirements than the "light" applications originally seen. This made it attractive to run applications in I/O domains so they could get bare-metal native I/O performance. This is leveraged by the Oracle SuperCluster engineered systems mentioned previously. In those engineered systems, I/O domains are used for high performance applications with native I/O performance for disk and network and optimized access to the Infiniband fabric. Another technical enhancement is Single Root I/O Virtualization (SR-IOV), which make it possible to give domains direct connections and native I/O performance for selected I/O devices. Not all I/O domains own PCI complexes, and there are increasingly more I/O domains that are not service domains. They use their I/O connectivity for performance for their own applications. However, there are some limitations and considerations: at this time, a domain using physical I/O cannot be live-migrated to another server. There is also a need to plan for security and introducing unneeded dependencies: if an I/O domain is also a service domain providing virtual I/O to guests, it has the ability to affect the correct operation of its client guest domains. This is even more relevant for the control domain. where the ldm command must be protected from unauthorized (or even mistaken) use that would affect other domains. As a general rule, running applications in the service domain or the control domain should be avoided. For reference, an excellent guide to secure deployment of domains by Stefan Hinker is at Secure Deployment of Oracle VM Server for SPARC. To recap: Guest domains with virtual I/O still provide the greatest operational flexibility, including features like live migration. They should be considered the default domain type to use unless there is a specific requirement that mandates an I/O domain. I/O domains can be used for applications with the highest performance requirements. Single Root I/O Virtualization (SR-IOV) makes this more attractive by giving direct I/O access to more domains, and by permitting dynamic reconfiguration of SR-IOV devices. Today's larger systems provide multiple PCIe buses - for example, 16 buses on the T5-8 - making it possible to configure multiple I/O domains each owning their own bus. Service domains should in general not be used for applications, because compromised security in the domain, or an outage, can affect domains that depend on it. This concern can be mitigated by providing guests' their virtual I/O from more than one service domain, so interruption of service in one service domain does not cause an application outage. The control domain should in general not be used to run applications, for the same reason. Oracle SuperCluster uses the control domain for applications, but it is an exception. It's not a general purpose environment; it's an engineered system with specifically configured applications and optimization for optimal performance. These are recommended "best practices" based on conversations with a number of Oracle architects. Keep in mind that "one size does not fit all", so you should evaluate these practices in the context of your own requirements. Summary Higher capacity servers that run Oracle VM Server for SPARC are attractive for applications with the most demanding resource requirements. New deployment models permit native I/O performance for demanding applications by running them in I/O domains with direct access to their devices. This is leveraged in SPARC SuperCluster, and can be leveraged in T-series servers to provision high-performance applications running in domains. Carefully planned, this can be used to provide peak performance for critical applications. That said, the improved virtual device performance in Oracle VM Server means that the default choice should still be guest domains with virtual I/O.

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  • USB Drive Warm Boot Issue. Cold boot = Perfect. Warm boot = "No boot sector found on USB device"

    - by Dan
    I'm experiencing a boot/reboot quirk similar to, yet somewhat different from others posted here. I have two Western Digital "Passport" external USB2 drives (160GB and 320GB) with Ubuntu 11.10 installed. The BIOS on my laptop is set to boot USB drives before the internal drive, and it works well. Either drive will cold-boot Ubuntu 11.10 perfectly. However, at times the computer must be restarted (warm boot) to have software updates or other changes take effect. When I warm-boot the computer, the computer goes through its normal shutdown/restart, then the usual BIOS tests, at which time the USB drive is selected momentarily (as normal), and that's when the trouble starts. I get a "No boot sector found on USB device", and the computer proceeds to boot Windows from the internal drive. If I press F12 early during the restart sequence (allows manual selection of the boot sequence), USB is still shown before the internal drive on the sequence list (as it should be). If I highlight "USB" and press ENTER, I still get a "No boot sector..." error message, but the external USB drive then proceeds to boot Ubuntu normally. I have a third external USB drive (Western Digital 160 GB Media Center) that cold-boots and warm-boots perfectly, so I know everything in the computer is set up properly. It also tells me Ubuntu is set up correctly on the drives, as all three drives were done identically, and at the same time. I've tried formatting the Passport drives NTFS and FAT32, but it didn't change anything. If I power-down the computer, then start it up again, it will boot Ubuntu from either of the Passport drives perfectly - every time. It's as if during a warm boot the Passport drives are somehow looking for the boot loader in the wrong location on the drive - yet either drives works when booting from a cold start. Not a show-stopper .. but frustrating. Computer is a Dell XPS M1530, A12 BIOS (latest), but I don't think the computer plays into the issue because one of the three drives works at all times. It's only the two WD Passport models at issue here. Thanks!

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  • Windows Server Backup "Reading Data; please wait..."

    - by Reafidy
    On windows Server 2008 R2 I have recently added the windows server backup (WSB) feature. Opening WSB I get the message "Reading Data; please wait...". This message fails to go away, even after leaving the server for over 12 hours. I also notice in the task manager that svchost.exe (username: networkservice) is using all available processing power. So I terminated that process and then WSB comes on-line. However after restarting the server and WSB the issue reoccurs. WSB also fails to recognize my store-in-go flash drive (2gb). What is the underlying problem here?

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  • Windows Server 2003 - Handling hundreds of simultaneous downloads

    - by Paul Hinett
    At the moment I have a single server with 4 1TB hard disks, daily I haver over 150 MP3 music files uploaded (around 80mb each). At busy periods there is over 300 people streaming / downloading these mixes all at once, 75% of the activity is on the most recently uploaded stuff which is all on a single hard disk. My read speads on the hard disk are very low due to such high activity of 200+ reads all happening at the same time on a single hard disk (ran some tests with HDTach). What would be a logical solution to solve this, a couple of ideas I had are: Load balance with another server Install faster hard disks (what are best these days? SCSI / SATA) Spread the most accessed files over the 4 drives so it is sharing the load between all 4 disks, instead of all the most accessed (most recent) all on the most recently installed drive. Obviouslly load balance is the most expensive option, but would it dramatically help? Some help on this situation would be great!

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  • DBan not working because disk has bad sectors?

    - by canadiancreed
    Attempting to wipe the drive of a laptop that I have before it's sold, and normally use DBAN to do so. However this time it starts and then finishes instantly with the following message. "DBAN finished with non-fatal errors This is usually cause by disks with bad sectors" Have tried multiple flags such as noverify to force it to skip this check (it doesn't show bad sectors in the OS scan in windows). but the error always comes back. This is the only time that I've seen this message, as every other of the few drives I've used this software on usually take 3-5 hours to do their job.

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  • Windows XP SP3 on Macbook Has Limited Disk Space

    - by Mikey.B
    Hi Guys, I setup Windows XP SP3 on a 40 GB partition using bootcamp (partition formatted for NTFS). For some reason, the hard drive properties only show ~3 GB of space available. Funny thing is though, I've hardly installed anything on the system... and if I open the windows explorer, select all directories, and check properties, it appears that I'm only using 11 GB of space. What gives? I thought there might be hidden files/folders so I enabled the option to show it but still nada. Has anyone come across this before? Any suggestions for how to proceed here?

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  • Windows 7 won't recognize backup set can I script extracting the files in some other way?

    - by datatoo
    The Windows 7 Backup/Restore created multiple backup sets and I was able to restore the oldest version, but not the most recent, which is not seen by the application. I do see all of the zip files and there are hundreds in later versions. Is there a way to extract each of these correctly outside of the regular restoration method? Perhaps scripting an extract of each day one after another? further clarifying The backup files were all made to an external drive. The original computer died completely, power supply, drives everything. I am trying to reconstruct as much as possible and the only backup set recognized is 6 months older. This was recovered over a new install, but unzipping thousands of zip files is not really a simple unzip copy project as the original paths are not a simple thing to reconstruct.

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  • How to fix corrupted filesystem (shows as RAW) in USB device?

    - by Erico Yan
    I would like to ask if you know how to fix a corrupted USB? I've tried the diskpart command but it didn't work. The media is write protected. Do you have any idea that is much better? I need to fix it because I have important files in my flash drive. I really need to retrieve it. I saw that the file system is seen as RAW and is unaccessible. I tried error checking, but it requires you to format it. I tried data recovery software but all files come out corrupted. My USB is Imation 4GB. Any suggestions?

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  • What Raid should I use for Website Static Files / Content

    - by Simon
    I'm building a Web server (IIS7) and would like to know the best practice for storing static content and the uploaded files of website's users (predominantly pictures, but also other documents like pdf's). I will keep the operating System on a Raid 1 array. Where should I be keeping the actual website's pages & files, it's own static content, and that of it's users? Should I be placing this content on a seperate raid array, and if so which type? I was considering using SLC SSD's (Such as the Intel's X25-e) but the following issues came to light. Will the SLC SSD's give any improvement over a 2.5" 15k SAS Drive for this type of content? If I did use SSD's, I'm under the belief I would still need to use Raid for redundancy, yet I've heard Intel X25-e's don't support TRIM. Does this scrap them as a legitimate option?

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  • Replacement Alternative for Dell FY606 in a Poweredge T105

    - by Mike C
    I have recently upgraded my Poweredge T105 server to use a SAS 6/ir RAID controller. Unfortunately, I did not realize at the time that adding the card would cause the BIOS to complain about a missing hard drive fan. This warning requires that a user press F1 to continue, which is disastrous in a server environment. I have searched all over found that the specific part I need is a Dell FY606 fan. However, I have yet to find a suitable retailer that covers this part. I have contacted Dell and they do not have this part in stock. Are there any alternative models of a fan that I could use in place of an FY606? Seems like a pretty straightforward part, just a fan that connects to a 4-pin power connector on the motherboard.

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  • Beeping Hard Disk - Seagate 250GB Momentus 5400.6

    - by Pez Cuckow
    I have been trying to repair a laptop that simply beeps instead of booting. After taking it apart I have now realised that it is the hard disk beeping. I know that may sound strange but I guarantee that is what it is! (Currently powered on it's own with a Sata Mains lead). The beeping is slightly faster than one per second there is a link to this recording. This recording was made resting the mic on the hard disk while it was sat on a table on it's own, there are no speakers anywhere near, the sound is coming from the hard disk. Does anyone know what this beep means? Is the hard drive just dead, or is it fixable and the data recoverable? Many thanks,

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  • How to boot Windows XP using the image file(not the extracted image file)

    - by Nrew
    Is it possible to boot from an iso image file itself. Because when you burn it, it gets extracted. Because in linux you can just place the .iso file in a removable media and boot from it without extracting. Is it possible to make something like that in windows? What I'm saying is related to this: http://wintoflash.com/forum/viewtopic.php?f=5&t=312 Something like creating a flash drive which has the ability to install multiple os. They have something like this in pendrivelinux but I can't find it anymore. But that boot manager can only install linux. And other live cd's used in cleaning the system. That's why I'm asking if its possible to make a custom windows xp or windows 7 installer so that the image file alone can boot.

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  • Used HDD/ran DiskSmartView/40,000 Power-on-hours?? should i trust it w/ my data, or take it back and bitch?

    - by David Lindsay
    I just bought a used hard drive from a University Surplus Store. Decided to run DiskSmartView to make sure it wasn't ready to fail. 40,000 power-on-hours I don't know if I feel like trusting my data to something that used. I really dont know if thats unreasonably old, but when i compare it to the POH reading i get when testing my other hdds its more than 3x older (my others have 2110 hours, 6150 hours, etc.. It's a Western Digital, so that gives me a little bit of hope(WDC WD4000KD-00NAB0). I could sure use someone else's opinion here. Thanks, DAVE

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  • Windows XP Installation issue - cannot find hard disk

    - by Marco
    A friend of mine gave me a laptop with Windows 8 installed and nothing else. I don't like it so I am trying to remove it by installing Windows XP. I have a windows XP installation CD that I have used before and worked fine, but didn't work when I tried to install it on the Windows 8 machine. It keeps telling me I don't have a drive to install to. Then I log into Windows 8 again and install check partitions. I found 2 and tried to make a new one but it will only let me make one of 69mb. Next, I tied to find a way to go back to XP with BCD install and try to set the boot loader for XP but it wasnt there. Somehow I deleted the bootloader for Windows 8 and now it asks me for a recovery tool for media. I am not familiar with the laptop specs, but it is a Toshiba with about 250GB storage, and above 1GHz processor.

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  • Why Both 8GB USB Flash Drives Have Different Integrities?

    - by Boris_yo
    USB 3.0 SuperTalent Express DUO 8GB recently had its partition corrupted and declared itself "write-protected" and I was told in chat by @sidran32 that this usually means that flash drive gone bad due to writing cycles limit being reached. Having this thumbdrive for over a year being used infrequently, I was in doubt and referred to SuperTalent's support. I was given recovery tool which I executed but it failed first time prompting me to reinsert it. After that, I formatted it with Windows 7 integrated format utility since recovery tool offered to do this as well which was successful. The problem as I have noticed is with integrity of SuperTalent: Compare above to SanDisk's Micro Cruzer 8GB: Am I missing something? Both thumbdrives are of 8GB and have same FAT32 file system.

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  • Error in using DBAN on HDD

    - by John Watson
    I am using DBAN to erase HDD. DBAN is loaded from a CD and BIOS Boot order has been set to favour CD drive. On starting laptop, system boots from CD and DBAN interface can be seen. DBAN detects two storage devices, HDD and the SD Card. My HDD IS 320GB but DBAN says 298GB. It erases the SD card but when i try to erase HDD, it gives following error. DBAN finished with non-fatal errors. *ERROR /dev/sdb (process crash) *ERROR /dev/sda (process crash)

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  • Laptop HDD failure imminent?

    - by Andrei Rinea
    I have an HP Compaq 615 laptop with an 160 GB 7200 rpm HDD. Hasn't been dropped or shaken, in fact it almost always stayed on my desk. I've treated it as nice as I could. The other day, however, my OS froze and I could hear a repeated clink-clink-clink coming from the HDD zone of the laptop. I had to switch off hardware-ly the laptop and re-start it. It worked very well after, including now. However I backed up immediately the core data on my USB drive and ordered an external USB HDD for periodic backups. Will it die soon or it was just a "blip"?

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  • DBan not working because disk has bad sectors? [migrated]

    - by canadiancreed
    Attempting to wipe the drive of a laptop that I have before it's sold, and normally use DBAN to do so. However this time it starts and then finishes instantly with the following message. "DBAN finished with non-fatal errors This is usually cause by disks with bad sectors" Have tried multiple flags such as noverify to force it to skip this check (it doesn't show bad sectors in the OS scan in windows). but the error always comes back. This is the only time that I've seen this message, as every other of the few drives I've used this software on usually take 3-5 hours to do their job.

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  • Defragment an Exchange Volume

    - by IceMage
    The Scenario: I use a dedicated volume (RAID volume) to store all of my data for my Exchange 2007 server. Today, out of curiosity, I decided to check up on how fragmented the files on this data volume were. To my surprise, the answer is extremely. So, a three part question: First and Foremost, SHOULD I defragment this volume (after a full backup of course)? Be specific as to why not if I should not, or reasons I absolutely should if I should. Second, about how much time should I allow for during this maintenance period per gigabyte. The drives are all 7200 RPM SATA drives on a Hardware RAID 5 controller (Perc 5i/6i, can't remember), the files are extremely fragmented. (Over 5000 file fragments per gigabyte). Third, is there something wrong here? It seems to me like the drive shouldn't be this fragmented. Could something be configured incorrectly that could be causing this to happen?

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  • Restoring factory image of HP Laptop

    - by Ahmed
    I use a HP G62. I am unable to use my recovery disk to restore to factory settings. I had no problems earlier until I created an additional partition which I hear might have changed my hard disk to dynamic. How do I get back to 'normal'? I don't mind formatting the disk. I just want my factory OS back. .............. i get an error message at about 69 percent telling me that the restoration process failed. I'm using the factory image disks i created using the hp recovery manager. I have tried formating the hard drive clean and then restoring woth the cd, it didn't work. I was always able to restore before i created that partition.

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  • Cannot see main user profile directory on old vista hdd on win7

    - by chaoskreator
    I have an old laptop HDD that ran Vista that I need to get some pictures and movies off of. I've attached it via SATA cable to my new Win 7 (64 bit) machine and it mounts fine, except I can't see the main user profile in the D:\Users directory. I've changed ownership and permissions for the D: drive to my C:\ Username but still no luck. I read something about it being caused by the UAC being active on the Vista machine. Is this true? Is there a way to disable this and gain access to the main profile without putting it back into the old laptop (it's fried and won't boot)?

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  • Ubuntu not showing disk

    - by ojek
    I have a laptop which had broken windows 7 installed on it. I created a ubuntu live usb and tried installing ubuntu over that win7. After a few minutes, I got an error message, so I needed to restart the computer. Now the laptop says that there is no bootable device - reasonable message given that there was an error during linux installation. But: Bios can see my hard drive, When I start ubuntu in live mode, and try either sudo fdisk -l or gparted, it doesn't show any hard disk drives. I am 90% sure that hdd is broken, but it is wierd that bios can see it, and ubuntu doesn't. How can I be 100% sure about that hdd? Is there any additional way of detecting my hdd from ubuntu?

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  • On booting my laptop warns me about failure of hard disk is imminent...can it be repaired or to be replaced..?

    - by nrb
    when I am booting my laptop (Lenovo G550) it gives an error message prior to that.. SMART Failure Predicted on Hard Disk O:Hitachi HTS543225l9A300-(PM) Warning : Immediately back up your data and replace your hard disk drive. Afailure may be imminent. Press F1 to continue.. Once it started, it runs smoothly, I also verified its status by running some internal HDD tests by Hard Disk Senitel software..It shows no bad sector , no virus, no damage , normal temperature ... it suggests every thing is OK except its health... Now my question is that then what is the wrong with it..? It may be wrong with plates (dusty) or the read/write heads...then can I go for repair it or replace it...? My system now reminds me every half an hour to resolve this problem since last 10 days... Help me.

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  • How to speed up rsync?

    - by Jakobud
    I'm running rsync to sync a directory onto my external USB HDD. It's about 150 gigs of data. 50000+ files I would guess. It's running it's first sync at the moment, but its copying files at a rate of only 1-5 MB/s. That seems incredibly slow for a USB 2.0 enclosure. There are no other transfers happening on the drive either. Here are the options I used: rsync -avz --progress /mysourcefolder /mytargetfolder I'm running Ubuntu Server 9.10.

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