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  • "Misaligned partition" - Should I do repartition (how?)

    - by RndmUbuntuAmateur
    Tried to install Ubuntu 12.04 from USB-stick alongside the existing Win7 OS 64bit, and now I'm not sure if install was completely successful: Disk Utility tool claims that the Extended partition (which contains Ubuntu partition and Swap) is "misaligned" and recommends repartition. What should I do, and if should I do this repartition, how to do it (especially if I would like not to lose the data on Win7 partition)? Background info: A considerably new Thinkpad laptop (UEFI BIOS, if that matters). Before install there were already a "SYSTEM_DRV" partition, the main Windows partition and a Lenovo recovery partition (all NTFS). Now the table looks like this: SYSTEM_DRV (sda1), Windows (sda2), Extended (sda4) (which contains Linux (sda5; ext4) and Swap (sda6)) and Recovery (sda3). Disk Utility Tool gives a message as follows when I select Ext: "The partition is misaligned by 1024 bytes. This may result in very poor performance. Repartitioning is suggested." There were couple of problems during the install, which I describe below, in the case they happen to be relevant. Installer claimed that it recognized existing OS'es fine, so I checked the corresponding option during the install. Next, when it asked me how to allocate the disk space, the first weird thing happened: the installer give me a graphical "slide" allocate disk space for pre-existing Win7 OS and new Ubuntu... but it did not inform me which partition would be for Ubuntu and which for Windows. ..well, I decided to go with the setting installer proposed. (not sure if this is relevant, but I guess I'd better mention it anyway - the previous partition tools have been more self-explanatory...) After the install (which reported no errors), GRUB/Ubuntu refused to boot. Luckily this problem was quite straightforwardly resolved with live-Ubuntu-USB and Boot-Repair ("Recommended repair" worked just fine). After all this hassle I decided to check the partition table "just to be sure"- and the disk utility gives the warning message I described.

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  • Deduping your redundancies

    - by nospam(at)example.com (Joerg Moellenkamp)
    Robin Harris of Storagemojo pointed to an interesting article about about deduplication and it's impact to the resiliency of your data against data corruption on ACM Queue. The problem in short: A considerable number of filesystems store important metadata at multiple locations. For example the ZFS rootblock is copied to three locations. Other filesystems have similar provisions to protect their metadata. However you can easily proof, that the rootblock pointer in the uberblock of ZFS for example is pointing to blocks with absolutely equal content in all three locatition (with zdb -uu and zdb -r). It has to be that way, because they are protected by the same checksum. A number of devices offer block level dedup, either as an option or as part of their inner workings. However when you store three identical blocks on them and the devices does block level dedup internally, the device may just deduplicated your redundant metadata to a block stored just once that is stored on the non-voilatile storage. When this block is corrupted, you have essentially three corrupted copies. Three hit with one bullet. This is indeed an interesting problem: A device doing deduplication doesn't know if a block is important or just a datablock. This is the reason why I like deduplication like it's done in ZFS. It's an integrated part and so important parts don't get deduplicated away. A disk accessed by a block level interface doesn't know anything about the importance of a block. A metadata block is nothing different to it's inner mechanism than a normal data block because there is no way to tell that this is important and that those redundancies aren't allowed to fall prey to some clever deduplication mechanism. Robin talks about this in regard of the Sandforce disk controllers who use a kind of dedup to reduce some of the nasty effects of writing data to flash, but the problem is much broader. However this is relevant whenever you are using a device with block level deduplication. It's just the point that you have to activate it for most implementation by command, whereas certain devices do this by default or by design and you don't know about it. However I'm not perfectly sure about that ? given that storage administration and server administration are often different groups with different business objectives I would ask your storage guys if they have activated dedup without telling somebody elase on their boxes in order to speak less often with the storage sales rep. The problem is even more interesting with ZFS. You may use ditto blocks to protect important data to store multiple copies of data in the pool to increase redundancy, even when your pool just consists out of one disk or just a striped set of disk. However when your device is doing dedup internally it may remove your redundancy before it hits the nonvolatile storage. You've won nothing. Just spend your disk quota on the the LUNs in the SAN and you make your disk admin happy because of the good dedup ratio However you can just fall in this specific "deduped ditto block"trap when your pool just consists out of a single device, because ZFS writes ditto blocks on different disks, when there is more than just one disk. Yet another reason why you should spend some extra-thought when putting your zpool on a single LUN, especially when the LUN is sliced and dices out of a large heap of storage devices by a storage controller. However I have one problem with the articles and their specific mention of ZFS: You can just hit by this problem when you are using the deduplicating device for the pool. However in the specifically mentioned case of SSD this isn't the usecase. Most implementations of SSD in conjunction with ZFS are hybrid storage pools and so rotating rust disk is used as pool and SSD are used as L2ARC/sZIL. And there it simply doesn't matter: When you really have to resort to the sZIL (your system went down, it doesn't matter of one block or several blocks are corrupt, you have to fail back to the last known good transaction group the device. On the other side, when a block in L2ARC is corrupt, you simply read it from the pool and in HSP implementations this is the already mentioned rust. In conjunction with ZFS this is more interesting when using a storage array, that is capable to do dedup and where you use LUNs for your pool. However as mentioned before, on those devices it's a user made decision to do so, and so it's less probable that you deduplicating your redundancies. Other filesystems lacking acapability similar to hybrid storage pools are more "haunted" by this problem of SSD using dedup-like mechanisms internally, because those filesystem really store the data on the the SSD instead of using it just as accelerating devices. However at the end Robin is correct: It's jet another point why protecting your data by creating redundancies by dispersing it several disks (by mirror or parity RAIDs) is really important. No dedup mechanism inside a device can dedup away your redundancy when you write it to a totally different and indepenent device.

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  • Can't boot to Ubuntu 11.10 after installation with Windows 7

    - by Tylor
    I just installed Ubuntu 11.10 on a machine with Windows 7 already installed. I want to setup the dualboot environment. I have a block of unallocated disk space at the end of the disk (some blog post suggested to do so). Then I started installing Ubuntu 11.10 on that part of disk. I installed the boot loader to /boot partition and the installation finished successfully. However, after installation, Ubuntu 11.10 doesn't show up on boot menu. Then I searched on Internet and I used EasyBCD to add a grub2 boot to boot menu. After this, the boot entry does show up in the boot menu, however it only boot into some sort of grub console. I tried many times, and it doesn't work. It looks like the boot loader is not properly installed? I only have one 1.5TB disk and the first 800GB is NTFS partition with Windows 7. Does this work?

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  • How can I fix the screen blurred while installing Ubuntu 12.10 Bate1

    - by Marslo
    I installed Ubuntu 12.10 Bate1 yesterday, but the screen blurred always shows after selecting Install Ubuntu on a Hard Disk option and before waiting for the installation interface. Click here to check the screenshot. The method of installation is by U-disk, the name of Ubuntu 12.10 is quantal-desktop-i386.iso (the download link is from Universal-USB-Installer), and Universal-USB-Installer was used to write the Ubuntu 12.10 into U-disk. PS. Ubuntu 12.04 could be installed successful on my computer!

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  • Enablement 2.0 Get Specialized

    - by mseika
    Oracle PartnerNetwork Specialized program is releasing new certifications on our latest products, and partners are invited to be the first candidates.Oracle Taleo Enterprise Cloud Service 2013 Specialization – Now Active!This specialization recognizes partner organizations that are proficient in positioning, selling and implementing Taleo’s Enterprise Talent Management solutions.Taleo's Talent Management Cloud helps organizations attract, develop, motivate and retain human capital to improve performance and drive growth. Oracle’s Taleo Enterprise Cloud Service 2013 Specialization encompasses the following products: Oracle Taleo Performance Management Cloud Service, Oracle Taleo Recruiting Cloud Service and Oracle Taleo Performance Management Cloud Service.Topics covered in this Specialization include: Selling and positioning Taleo’s Talent Management Cloud; Functional and Technical positioning. Implementation tracks are included for Taleo Performance Management Cloud Service, Oracle Taleo Recruiting Cloud Service and Oracle Taleo Performance Management Cloud Service. Oracle partners who achieve this Specialization are differentiated in the marketplace through proven expertise in Oracle Taleo Enterprise Cloud Service.New Certified Implementation Specialist Exam in Production! Oracle Taleo Recruiting Cloud Service 2013 Certified Implementation Specialist (1Z0-474) All Beta exam participants will receive their exam scores as of beginning of July 2013. The successful candidates will receive their certificates starting mid-July 2013. Take the exam now at a near-by Pearson VUE testing center!Contact Us Please direct any inquiries you may have to Oracle Partner Enablement team at [email protected].

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  • Enablement 2.0 Get Specialized

    - by mseika
    Oracle PartnerNetwork Specialized program is releasing new certifications on our latest products, and partners are invited to be the first candidates.Oracle Taleo Enterprise Cloud Service 2013 Specialization – Now Active!This specialization recognizes partner organizations that are proficient in positioning, selling and implementing Taleo’s Enterprise Talent Management solutions.Taleo's Talent Management Cloud helps organizations attract, develop, motivate and retain human capital to improve performance and drive growth. Oracle’s Taleo Enterprise Cloud Service 2013 Specialization encompasses the following products: Oracle Taleo Performance Management Cloud Service, Oracle Taleo Recruiting Cloud Service and Oracle Taleo Performance Management Cloud Service.Topics covered in this Specialization include: Selling and positioning Taleo’s Talent Management Cloud; Functional and Technical positioning. Implementation tracks are included for Taleo Performance Management Cloud Service, Oracle Taleo Recruiting Cloud Service and Oracle Taleo Performance Management Cloud Service.Oracle partners who achieve this Specialization are differentiated in the marketplace through proven expertise in Oracle Taleo Enterprise Cloud Service.  New Certified Implementation Specialist Exam in Production! Oracle Taleo Recruiting Cloud Service 2013 Certified Implementation Specialist (1Z0-474) All Beta exam participants will receive their exam scores as of beginning of July 2013. The successful candidates will receive their certificates starting mid-July 2013.   Take the exam now at a near-by Pearson VUE testing center!Contact Us Please direct any inquiries you may have to Oracle Partner Enablement team at [email protected].

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  • Enablement 2.0 Get Specialized

    - by mseika
    Oracle PartnerNetwork Specialized program is releasing new certifications on our latest products, and partners are invited to be the first candidates.Oracle Taleo Enterprise Cloud Service 2013 Specialization – Now Active!This specialization recognizes partner organizations that are proficient in positioning, selling and implementing Taleo’s Enterprise Talent Management solutions.Taleo's Talent Management Cloud helps organizations attract, develop, motivate and retain human capital to improve performance and drive growth. Oracle’s Taleo Enterprise Cloud Service 2013 Specialization encompasses the following products: Oracle Taleo Performance Management Cloud Service, Oracle Taleo Recruiting Cloud Service and Oracle Taleo Performance Management Cloud Service.Topics covered in this Specialization include: Selling and positioning Taleo’s Talent Management Cloud; Functional and Technical positioning. Implementation tracks are included for Taleo Performance Management Cloud Service, Oracle Taleo Recruiting Cloud Service and Oracle Taleo Performance Management Cloud Service. Oracle partners who achieve this Specialization are differentiated in the marketplace through proven expertise in Oracle Taleo Enterprise Cloud Service.New Certified Implementation Specialist Exam in Production! Oracle Taleo Recruiting Cloud Service 2013 Certified Implementation Specialist (1Z0-474) All Beta exam participants will receive their exam scores as of beginning of July 2013. The successful candidates will receive their certificates starting mid-July 2013. Take the exam now at a near-by Pearson VUE testing center!Contact Us Please direct any inquiries you may have to Oracle Partner Enablement team at [email protected].

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  • Enablement 2.0 Get Specialized

    - by mseika
    Oracle PartnerNetwork Specialized program is releasing new certifications on our latest products, and partners are invited to be the first candidates.Oracle Taleo Enterprise Cloud Service 2013 Specialization – Now Active!This specialization recognizes partner organizations that are proficient in positioning, selling and implementing Taleo’s Enterprise Talent Management solutions.Taleo's Talent Management Cloud helps organizations attract, develop, motivate and retain human capital to improve performance and drive growth. Oracle’s Taleo Enterprise Cloud Service 2013 Specialization encompasses the following products: Oracle Taleo Performance Management Cloud Service, Oracle Taleo Recruiting Cloud Service and Oracle Taleo Performance Management Cloud Service. Topics covered in this Specialization include: Selling and positioning Taleo’s Talent Management Cloud; Functional and Technical positioning. Implementation tracks are included for Taleo Performance Management Cloud Service, Oracle Taleo Recruiting Cloud Service and Oracle Taleo Performance Management Cloud Service.Oracle partners who achieve this Specialization are differentiated in the marketplace through proven expertise in Oracle Taleo Enterprise Cloud Service.New Certified Implementation Specialist Exam in Production! Oracle Taleo Recruiting Cloud Service 2013 Certified Implementation Specialist (1Z0-474) All Beta exam participants will receive their exam scores as of beginning of July 2013. The successful candidates will receive their certificates starting mid-July 2013. Take the exam now at a near-by Pearson VUE testing center!Contact Us Please direct any inquiries you may have to Oracle Partner Enablement team at [email protected].

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  • Is it OK to create all primary partitions.?

    - by james
    I have a 320GB hard disk. I only use either ubuntu or kubuntu (12.04 for now). I don't want to use windows or any other dual boot os. And i need only 3 partitions on my hard disk. One for the OS and remaining two for data storage. I don't want to create swap also. Now can i create all primary partitions on the hard disk. Are there any disadvantages in doing so. If all the partitions are primary i think i can easily resize partitions in future. On second thought i have the idea of using seperate partition for /home. Is it good practice . If i have to do this, i will create 4 partitions all primary. In any case i don't want to create more than 4 partitions . And i know the limit will be 4. So is it safe to create all 3 or 4 primary partitions. Pls suggest me, What are the good practices . (previously i used win-xp and win-7 on dual boot with 2 primary partitions and that bugged me somehow i don't remember. Since then i felt there should be only one primary partition in a hard disk.) EDIT 1 : Now i will use four partitions in the sequence - / , /home , /for-data , /swap . I have another question. Does a partition need continuous blocks on the disk. I mean if i want to resize partitions later, can i add space from sda3 to sda1. Is it possible and is it safe to do ?

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  • UbuntuStudio 12.04 does not boot after install - no "intrd" image

    - by user72705
    After installing Ubuntu Studio 12.04 from DVD onto the fourth hard disk, it fails to boot, even when explicitly choosing the fourth hard disk as the boot device. I have SUSE 11.2 on the first 2 SCSI disks (which form a RAID) and Studio64 on the 1st IDE disk (that is, the third disk). Looking at the /boot directory on the Ubuntu partition, I see there is no initrd image. Editing the GRUB configuration file to include (hd3,1)/vmlinuz and of course (hd3,1)/initrd should fix the problem. But still GRUB gives a file not found error. This appears to me that, no mkintrd during the booting process (checked with LiveCD) runs like in OpenSUSE. How do I create the initrd to make Ubuntu bootable.

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  • Grub not loading after Windows 8 Install

    - by RazorXsr
    My system was configured to dual boot Ubuntu 12.04.1 LTS and Windows 7. Today I got my hands on the MSDN release of Windows 8 and I installed it over my Windows 7. Now the computer just boots to Windows 8 directly without loading the GRUB screen. So I followed the steps as suggested in: https://help.ubuntu.com/community/RecoveringUbuntuAfterInstallingWindows. Running this command: ls -l /dev/disk/by-label/ gives the following output: total 0 lrwxrwxrwx 1 root root 10 Sep 11 07:51 Entertainment -> ../../sda2 lrwxrwxrwx 1 root root 10 Sep 11 02:45 PENDRIVE -> ../../sdb1 Also fdisk -l command gives this as the output: Disk /dev/sda: 320.1 GB, 320072933376 bytes 255 heads, 63 sectors/track, 38913 cylinders, total 625142448 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x1246aa23 Device Boot Start End Blocks Id System /dev/sda1 * 2048 319582199 159790076 7 HPFS/NTFS/exFAT /dev/sda2 319582208 602906623 141662208 7 HPFS/NTFS/exFAT /dev/sda3 602908672 625135615 11113472 83 Linux Disk /dev/sdb: 1939 MB, 1939865600 bytes 64 heads, 63 sectors/track, 939 cylinders, total 3788800 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0xc3072e18 Device Boot Start End Blocks Id System /dev/sdb1 * 2248 3788799 1893276 c W95 FAT32 (LBA) So I assume that I have to run this: sudo grub-install /dev/sda3 to get GRUB up and running. But I am getting this error: /usr/sbin/grub-probe: error: cannot find a device for /boot/grub (is /dev mounted?). Can anyone please guide me in the right direction? The current Ubuntu installation is far too customized to my needs to lose it to a boot manager issue! Any help is much appreciated!

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  • Ubuntu 12.04 USB (HP)

    - by xShadoWolf
    I have put ubuntu 12.04 on a USB (Kingston 8GB) and I go to install and I can't it gives options for erase and something else I have 4 primary partitions win7 for my main partition and 3 created by HP HP_TOOLS, HP_RECOVERY and SYSTEM To get to my point how do I install ubuntu on HDD I have a HP probook 200 notebook PC. Can I remove any partitions? When I do sudo fdisk -l This Comes Up Disk /dev/sda: 500.1 GB, 500107862016 bytes 255 heads, 63 sectors/track, 60801 cylinders, total 976773168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x3ed7e7b0 Device Boot Start End Blocks Id System /dev/sda1 * 2048 409599 203776 7 HPFS/NTFS/exFAT /dev/sda2 409600 946591743 473091072 7 HPFS/NTFS/exFAT /dev/sda3 946591744 976560127 14984192 7 HPFS/NTFS/exFAT /dev/sda4 976560128 976771119 105496 c W95 FAT32 (LBA) Disk /dev/sdb: 7803 MB, 7803174912 bytes 122 heads, 58 sectors/track, 2153 cylinders, total 15240576 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0xc3072e18 Device Boot Start End Blocks Id System /dev/sdb1 * 8064 15240575 7616256 c W95 FAT32 (LBA)

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  • No Windows Option on Boot

    - by Okoning
    I've installed Ubuntu alongside Windows but at first didn't have a boot option menu. So, I installed bootrepair and ran it. This succeeded in granting me a GRUB boot option menu, but Windows isn't on it. Here is the bootrepair report: http://paste.ubuntu.com/8098527 Can anyone tell me what might be wrong? EDIT: I ran sudo fdisk -l and this is the output: Disk /dev/sda: 500.1 GB, 500107862016 bytes 255 heads, 63 sectors/track, 60801 cylinders, total 976773168 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00023fe0 Device Boot Start End Blocks Id System /dev/sda1 * 2048 960096255 480047104 83 Linux /dev/sda2 960098302 976771071 8336385 5 Extended /dev/sda5 960098304 976771071 8336384 82 Linux swap / Solaris Disk /dev/sdb: 32.0 GB, 32015679488 bytes 255 heads, 63 sectors/track, 3892 cylinders, total 62530624 sectors Units = sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 512 bytes I/O size (minimum/optimal): 512 bytes / 512 bytes Disk identifier: 0x00000000 Device Boot Start End Blocks Id System /dev/sdb1 * 32 62530623 31265296 c W95 FAT32 (LBA)

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  • Stop Windows boot

    - by Parley Applegate
    Installed Ubuntu over a Windows8 trial. After installation, Windows8 still tries to boot. Wiped disk clean with Acronis and reinstall Ubuntu. Windows8 still tries to start, but goes to blank screen. Ubuntu never tries to boot. Naturally live mode works fine. What do you think of wiping disk again, install Windows7 and try using GRUB approach or do you know how to remove Windows from the cleaned disk?

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  • Can't install Ubuntu 11.10 on a seperate disk partition. I have a log file. Please help!

    - by les02jen17
    Before I installed Ubuntu, I resized my C: drive (which has my Windows 7 OS). Prior to resizing, I even defragged the said drive. I tried using Wubi to install it on the created partition, but I receive an error. I have the log file and I would post it but it's too long and the site won't let me. :(So anyway, I wasn't able to install it, so I uninstalled it. Upon uninstalling Wubi and Ubuntu, I tried installing it by having the CD to my CD ROM. The installation was a success, however, upon rebooting I can neither boot to Ubuntu OR Windows 7. I get stuck in an infinite bootloop. I hope you can help me out! :(

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  • How DBAs Can Tune Distributed IBM DB2 Applications

    Many critical business applications now execute in an environment separate from that of the enterprise database server. The database administrator often finds monitoring and performance tuning of these "distributed" applications to be especially difficult. This article looks at common performance issues of distributed applications and presents advice to assist the IBM DB2 database administrator in mitigating performance problems.

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  • MySQL December Webinars

    - by Bertrand Matthelié
    We'll be running 3 webinars next week and hope many of you will be able to join us: MySQL Replication: Simplifying Scaling and HA with GTIDs Wednesday, December 12, at 15.00 Central European TimeJoin the MySQL replication developers for a deep dive into the design and implementation of Global Transaction Identifiers (GTIDs) and how they enable users to simplify MySQL scaling and HA. GTIDs are one of the most significant new replication capabilities in MySQL 5.6, making it simple to track and compare replication progress between the master and slave servers. Register Now MySQL 5.6: Building the Next Generation of Web/Cloud/SaaS/Embedded Applications and Services Thursday, December 13, at 9.00 am Pacific Time As the world's most popular web database, MySQL has quickly become the leading cloud database, with most providers offering MySQL-based services. Indeed, built to deliver web-based applications and to scale out, MySQL's architecture and features make the database a great fit to deliver cloud-based applications. In this webinar we will focus on the improvements in MySQL 5.6 performance, scalability, and availability designed to enable DBA and developer agility in building the next generation of web-based applications. Register Now Getting the Best MySQL Performance in Your Products: Part IV, Partitioning Friday, December 14, at 9.00 am Pacific Time We're adding Partitioning to our extremely popular "Getting the Best MySQL Performance in Your Products" webinar series. Partitioning can greatly increase the performance of your queries, especially when doing full table scans over large tables. Partitioning is also an excellent way to manage very large tables. It's one of the best ways to build higher performance into your product's embedded or bundled MySQL, and particularly for hardware-constrained appliances and devices. Register Now We have live Q&A during all webinars so you'll get the opportunity to ask your questions!

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  • ???????/?????!?????????????????

    - by user788995
    ????? ??:2012/01/23 ??:??????/?? ??????????????????????????????????Disk I/O???????????????????Disk I/O???????????????????????????????????????????????????? ??????????????????????????????????????????????????????? / ?????????????????Appendix ????????? ????????????????? http://otndnld.oracle.co.jp/ondemand/otn-seminar/movie/120106_D-12_Disk_1.wmv http://otndnld.oracle.co.jp/ondemand/otn-seminar/movie/mp4/120106_D-12_Disk_1.mp4 http://www.oracle.com/technetwork/jp/ondemand/db-technique/d-12-disk-1484778-ja.pdf

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  • PostgreSQL, Foreign Keys, Insert speed & Django

    - by Miles
    A few days ago, I ran into an unexpected performance problem with a pretty standard Django setup. For an upcoming feature, we have to regenerate a table hourly, containing about 100k rows of data, 9M on the disk, 10M indexes according to pgAdmin. The problem is that inserting them by whatever method literally takes ages, up to 3 minutes of 100% disk busy time. That's not something you want on a production site. It doesn't matter if the inserts were in a transaction, issued via plain insert, multi-row insert, COPY FROM or even INSERT INTO t1 SELECT * FROM t2. After noticing this isn't Django's fault, I followed a trial and error route, and hey, the problem disappeared after dropping all foreign keys! Instead of 3 minutes, the INSERT INTO SELECT FROM took less than a second to execute, which isn't too surprising for a table <= 20M on the disk. What is weird is that PostgreSQL manages to slow down inserts by 180x just by using 3 foreign keys. Oh, disk activity was pure writing, as everything is cached in RAM; only writes go to the disks. It looks like PostgreSQL is working very hard to touch every row in the referred tables, as 3MB/sec * 180s is way more data than the 20MB this new table takes on disk. No WAL for the 180s case, I was testing in psql directly, in Django, add ~50% overhead for WAL logging. Tried @commit_on_success, same slowness, I had even implemented multi row insert and COPY FROM with psycopg2. That's another weird thing, how can 10M worth of inserts generate 10x 16M log segments? Table layout: id serial primary, a bunch of int32, 3 foreign keys to small table, 198 rows, 16k on disk large table, 1.2M rows, 59 data + 89 index MB on disk large table, 2.2M rows, 198 + 210MB So, am I doomed to either drop the foreign keys manually or use the table in a very un-Django way by defining saving bla_id x3 and skip using models.ForeignKey? I'd love to hear about some magical antidote / pg setting to fix this.

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  • Adding more RAM at different speeds? Will it impact performance as much as to make it worse than without adding it?

    - by user1676874
    I got a new laptop with 4GBs of ram, expandable to 8GBs. It has 1 4GB stick DDR3 PC3-12800 at 1600Mhz. I can't seem to find another one exactly the same locally, the closest I've found is 1 4GB stick DDR3 PC3-10600 at 1333Mhz. So my question is, I know they will both run at the slowest speed, so even if I have more available RAM it will become slower. Is the performance loss big enough to make the upgrade not worth the hassle?

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