Search results

  1. C

    So I have a Raid 6 array, but is slow. Raid 10 any better?

    I find it strange that no one asks for the RAID engine used - which would make all the difference even despite the use of SMR drives. If there are only contiguous writes, his performance should not be bad at all. But assuming he uses some Windows-based FakeRAID/onboardRAID, performance will be...
  2. C

    software raid, multiple controllers, btrfs

    With static device node i meant that if you change the cabling or connect the drive to another controller, does it automatically pick that up upon reboot, even if you use static nodes like /dev/sda, like on BSD?
  3. C

    LSI 9240-8i RAID0 vs X99 onboard RAID0

    Start using a proper benchmark like CrystalDiskMark instead of ATTO - ancient benchmark. Also, in many cases FakeRAID from using Windows-only drivers (Intel chipset, AMD chipset) results in higher performance, particularly for SSD arrays. Hardware RAID controllers tend to do better in RAID5 and...
  4. C

    Questions about Dell H200 Raid Controller after flashing

    Well, if using the chipset SATA, it may not be supported by the hardware. But if you use an addon controller you use different hardware. So it would be supported. You only need an operating system which has an AHCI driver, on Windows that is msahci.sys and on BSD that is 'ada' driver. On Linux...
  5. C

    software raid, multiple controllers, btrfs

    Does Btrfs on Linux use static device nodes and no 'device tasting' such as ZFS under BSD?
  6. C

    Questions about Dell H200 Raid Controller after flashing

    I recommend you use an AHCI controller as opposed to a SAS controller, for various reasons. Unless you absolute need maximum performance and you require 2GB/s transfers, the PCIe 2.0 x2 interface will give you up to 1GB/s and this should be more than adequate. Try this controller instead...
  7. C

    Hard Drive Powering Off

    @tonyyy: that has nothing to do with spindown. WD Green has Headparking, which means the head that reads and writes is parked and the forces that overcome the permanent magnet are powered down, saving about 0,4 watts of power. It will not do anything about the motor that spins the platters at...
  8. C

    ZFS: 120GB SSD for L2ARC or ZIL?

    And i have responded to those quotes with a response that i believe you have not responded to? The quotes from the Intel representative were ambiguous, stating that Intel S3500/S3700 SSDs would protect writes that 'have been confirmed'. This could refer to writes that have been confirmed by a...
  9. C

    ZFS: 120GB SSD for L2ARC or ZIL?

    Yes i have addressed this with AnandTech editor HellHammer. The same applies to newer Intel SSDs like S3500 and S3700. Only the Intel 320 protects the full write-back which is 256KiB SRAM internally in the chip - the DRAM chip is not used to buffer writes. Losing the data in DRAM however is not...
  10. C

    ZFS: 120GB SSD for L2ARC or ZIL?

    You can use one SSD for both tasks using partitions. Using a non-protected SSD for sLOG (dedicated ZIL) could be the equivalent of having no ZIL at all. You need an SSD with power-safe capacitors that honours the FLUSH command. That is not Samsung or Sandforce or other consumer-grade drives...
  11. C

    New Synology uses Btrfs

    Just like Ext4 was 'production ready' when it was made the default filesystem in Ubuntu a couple years back. The result is thousands of systems with filesystem corruption, and many patches that followed that addressed the corruption bugs. Even ZFS still has corruption bugs; a few months back...
  12. C

    Possibly going to build my own NAS, big Q

    I cannot help you with the casing, but i use J1900 'atom' boards a lot for ZFS servers so may be able to help you with that. I like these boards: ASRock Q1900DC-ITX ASRock N3150DC-ITX - http://www.asrock.com/mb/Intel/N3150DC-ITX/ This last board is basically the same as the former, but...
  13. C

    Possibly going to build my own NAS, big Q

    Why? Why do you need to 'set up a whole new vdev larger than this one' ? You can add two disks in a mirror if you like. I do not recommend it, but it is possible. You can start with 6 disks in RAID-Z2 and add 10 disks in RAID-Z2. But you can just as well do it the other way around. Maybe i...
  14. C

    Possibly going to build my own NAS, big Q

    I can respect that. Still, it somewhat reads to me like: "I have been smoking for 30 years now and it is working well for me". Sure that can be true. But ugh! Smoking is bad. Just like old filesystems are BAD! Everyone should know that. It is simply of a different era. And the problem of uBER is...
  15. C

    Possibly going to build my own NAS, big Q

    Why on earth would you want a proprietary and legacy solution like unRAID if you can use ZFS - by far the best storage technology out there. It has limitations on expansion, but that's about it. Only benefits. All the legacy solutions have major drawbacks. The biggest is that they offer no true...
  16. C

    4x RAID 0 vs M.2

    If you already have them and the performance difference will be extremely minimal, why bother buying something different? Stick with what you have?!
  17. C

    4x RAID 0 vs M.2

    DMI 2.0 is about PCIe 2.0 x4 i believe, so 2GB/s. I believe newer chipsets of Skylake platform have DMI 3.0 which is about the same as PCIe 3.0 x4 so ~4GB/s. The chipset SATA ports generally are the best SATA ports you are able to get. True, but you guys are forgetting that SSDs internally...
  18. C

    Formatting a 3TB MyBook to 512 Cluster Size?

    This concerns sector size, not cluster size. And what drescherjm says is most likely true: it is not the drive but it is the external casing. It increases the sector size of the drive to allow capacities higher than 2TiB without the need for GPT partition scheme. Beware however that removing...
  19. C

    Western Digital Is Trying to Fool You

    Red and Green are physically the same drive, only a tiny vibration sensor is what separates them physically. The Red has minor firmware tweaks (TLER enabled + different headparking setting) and it has additional warranty: 3 years instead of 2 years in the EU or instead of 1 years outside of the...
  20. C

    CRC Error Count

    Could you show me the SMART output of one drive where attribute #198 does have the 'Online' flag set? I would be surprised if you can find one. The name of the attribute indeed can vary, but i think the actual mechanic behind this attribute does not. Only the (offline) period when it is updated...
  21. C

    CRC Error Count

    What exactly is incorrect about it? Just trying to learn from you by the way, not trying to nitpick. :) I can at least confirm that Offline Uncorrectable can trigger without ever having run a SMART test, but only during host reads. Again, it may be possible that individual drives or brands...
  22. C

    CRC Error Count

    They generally are true for all recent consumer-grade drives by a simple function of mathematics. Consumer-grade drives get specified uBER 10^-14. For lower capacities and duty cycles, this results in very few bad secors due to insufficient ECC correcting capability, but with todays drives with...
  23. C

    CRC Error Count

    Well, i explained it in my post, but if you want additional comment on it, here goes: This description is pretty much accurate, but concerns Current Pending Sector instead. Also, it will apply to the first unsuccessful read attempt - often having triggered recovery. But the recovery can be...
  24. C

    CRC Error Count

    Well i have 32GiB RAM at three of my NAS systems which use ZFS. This means memory bitflips will be detected in the form of disk corruption. Not one checksum error has arisen in the many years of service (4-5 years i think). So ECC for RAM is nice but in many circumstances you can do without. If...
  25. C

    Western Digital Is Trying to Fool You

    Well first they hidden the rpm behind IntelliPower which is just a marketing way of not wanting to say they are 5400rpm-class drives. In fact they were so vague in the beginning that many people including reviewsites interpreted this as having a variable RPM. No such drive exists - all drives...
  26. C

    CRC Error Count

    patrickdk, i think that is not really correct. In my experience: ECC corrected means ECC error correction was necessary to read the sector properly (i.e. without bits being flipped/corrupted). Not all reads require ECC, but many reads do since harddrives with high data density have long passed...
  27. C

    Caution! 50% Performance on M.2 SSD's and ITX Boards

    This is no issue for normal desktop usage other than benchmarking. When not used the SSD will return to a very low power state (DIPM/HIPM) and consume about 0.1 watts. This will allow the SSD to cool down. Furthermore, the placement of the M.2 underneath the motherboard will limit heat...
  28. C

    Change from 512 byte sectors to 4k size?

    ZFS uses a dynamic stripesize - and thus can vary from <sectorsize> (usually 512B) to 128KiB, or with large_blocks feature up to 1024K. This does not mean every file will take 128KiB. Stripesize also should not be confused with cluster size. You can have a 1024K stripesize but a 512B cluster...
  29. C

    CRC Error Count

    Those are cabling errors. The fact that you 'see' this in the SMART output is normal; post the SMART output here to get relevant replies. The raw value is the place to look at. If it is above 0, then you had cable errors in the past. It does not mean you still have cabling errors, though. Only...
  30. C

    Change from 512 byte sectors to 4k size?

    This is wrong. I think you mean cluster size, not sector size. That is a major difference. The sectorsize is determined by the storage device, not by the filesystem. Cluster size is a filesystem setting and the SSD/HDD will not care what you select here. Leave it at its default setting.
  31. C

    Change from 512 byte sectors to 4k size?

    Formatting today means initialising the filesystem; what exactly do you mean with 'format to 4k' or 'format to 512 byte' - that is not clear to me. Almost all harddrives and SSDs use 512 byte sectorsize, even though the harddrive uses 4KiB sectors and the SSD uses 8KiB pages. But this remains...
  32. C

    Best SSDs currently?

    Crucial MX200 because you can use it as SLC SSD if you use no more than half its capacity. Only works for the 250GB SATA model and the 250/500GB M.2 models. But better than this you cannot get. Also, Crucial gives you capacitors + MLC NAND memory for less money than Samsung TLC drives. Which is...
  33. C

    SSD Raid 0

    If people want a single larger volume, buying a bigger SSD is the easiest. Also JBOD - also known as concatenating or spanning - will do the same thing, but without the performance benefit RAID0 offers. I in fact do recommend considering buying two smaller SSDs. Besides the small performance...
  34. C

    SSD Raid 0

    Your SSD already uses RAID0 internally - or interleaving - so having two modern SSDs in RAID0 is like moving from a 16-disk RAID0 to a 32-disk RAID0. Your SSD array will get faster - up to twice as fast for both sequential and random I/O - but it cannot improve the most important performance...
  35. C

    NAS o new server

    For ZFS the importance of ECC memory is actually less, because ZFS at least can eventually detect all on-disk corruption caused by RAM bitflips (checksum invalid or data invalid) and can correct many on-disk corruption caused by RAM bitflips. Your client, however, cannot do this and thus might...
  36. C

    NAS o new server

    QNAP is legacy storage - you will not receive the benefits of advanced filesystems like ZFS. Perhaps you can consider a low-end ZFS build instead? They are cheap - cheaper than prebuilt NAS systems, and very low power too. Only costs you a few hours to assemble and setup the thing. Try this...
  37. C

    Any reason a drive should just stop or turn off? FreeBSD/ZFS

    It would, but only if the sector has been physically damaged. In most cases, it concerns unreadable sectors without physical damage. This is due to uBER: uncorrectable Bit-Error Rate which increasingly is becoming a problem as data densities grow but ECC errorcorrection stays the same. So only...
  38. C

    Any reason a drive should just stop or turn off? FreeBSD/ZFS

    By doing this you have destroyed the evidence since running such tests can make pending sectors disappear. It will leave no trace in the SMART data. Next time, secure the SMART data first prior to using any active utility or reading/writing anything from/to the drive. Because right now...
  39. C

    NAS o new server

    A game server generally does not access the texture information and such, but only the essential game data which can be very limited in size. That is, it might still require big files because they contain everything, but it might only access small portions within those huge files. If this is...
  40. C

    Seagate SAS in SM JBOD - lots of read errors (anyone else?)

    Well you have not provided one key reason to pay the premium price for disks with SAS interface. There are also disks of the same class with SATA interface, such as the Velociraptor. Basically a SAS drive with SATA interface. There you also get many of the characteristics that SAS drives have to...
Top