Recent content by sub.mesa

Assuming you do a memtest prior to storing data, and you check the zpool status output for corruption regularly, I see no need for the emphasis on requiring ECC memory. Yes, ECC is a good idea for pretty much all computers. But despite some articles that suggest ZFS is very vulnerable to...

On BSD platforms there are the tunables. vfs.zfs.zil_disable vfs.zfs.zil_replay_disable However, disabling ZIL altogether is not recommended and I believe this tunable was removed in recent releases. It's not really required now that you can tune sync write behavior on specific filesystems...

Indeed. Is this thing actually for sale? It would be an excellent choice for a highend yet compact ZFS NAS server.

SLOG is nothing more than storing the ZIL on a dedicated drive. Without SLOG, your ZIL would be stored on the main pool instead. Sync=disabled means the sync writes will not be written to ZIL (intent log) first. Whether you are using SLOG (dedicated ZIL) or using regular ZIL, will not matter in...

You mean 'ad0-9' or 'ada0-9' I presume? I do recommend to flash your LSI controller in IT-mode firmware. IR will work, but may have side effects the IT doesn't have. The IR-mode firmware uses a different driver for the LSI2008 SAS controller chip. Whether you flash it or not, any disks...

If you do your research you will know Samsung is missing a few protections that other SSDs do have. Probably you would want to consider the M500 from Crucial as well. It is both cheaper than Samsungs offerings and offers more protections. It only offers lower sequential write speeds, but in many...

Today Sandforce isn't as bad as it used to be; all the OCZ consumers were used as guinea pig to iron out all the Sandforce bugs. But even with a stable controller, OCZ manages to screw up. For example by overclocking the controller for some extra benchmark results, but potentially higher RMA...

OCZ is nothing but a disaster for consumers, which get tricked by fake specifications and are awarded inferior products for the same price as honest and proper products. It's surprising how much second chances consumers award to OCZ, even though they are being ripped off multiple times. The...

A brand new SSD - even 25nm TLC one - will have about 10 years of retention when you start using it. Only when the flash degrades, will the retention drop significantly. When all the write cycles have been exhausted - on paper at least - you should still have 12 months of retention. So it...

Legacy RAID engines treat disks as either good or bad; nothing in between. A disk with terabytes of data but one tiny sector that cannot be read, is considered to be a failed disk from the viewpoint of the RAID engine. Of course, that is why you should not use legacy RAID, but instead migrate...

If by 'DMA errors' you mean UDMA CRC Error Count, then you replaced your drives for nothing; UDMA CRC Errors mean cabling errors and most likely are not the fault of the drive in question. @Topicstarter; i see no CrystalDiskInfo screenshot, just some pasted data. If it's right, then you've...

@omniscence, striping RAID can linearly increase IOps as queue depth grows, and for writes it requires less queue depth to scale. Of course, desktop appliations are limited in IOps and the SSD is much to fast for the system to really use all interleaving channels optimally.

Probably you are using Areca with non-TLER drives with uBER of 10^-14 or something like that. That is asking for trouble. Areca = legacy RAID. Your data is not gone however, once you clear the bad sectors on the disks you can reattach the detached disk and at least get a degraded array. I...

Not sure what the pricing is in your area, but here in Europe the M500 is a tad cheaper. But it packs extra protection in terms of power-safe capacitor array that can prevent retroactive datacorruption on SSDs. All SSDS based on NAND flash are vulnerable without power protection. People who...

TLER is no more than a workaround for faulty RAID engines. There is no reason a good RAID5 engine would need TLER. ZFS RAID-Z is one example; and the differences between RAID-Z and RAID5 are irrelevant to the harddrive. Upon reading an unreadable sector on a harddrive, the harddrive would...