This piece of code performs verification. I don’t know whether it is available in a precompiled form though.
But consider that:
Any data that is bad, but the satellite no longer expects the node to store it, will be garbage collected anyway, usually within two weeks.
Out of the files that the satellite does expect the node to store, if there’s >4% of bad files, the node will be disqualified anyway.
So running this kind of data scan could maybe save you <4% of disk space. Doesn’t get you much for potentially days of constant I/O and reduced node performance.
This was discussed many, many times. Short answer, for the reasons I point above there’s little value in doing so. Storj’s built-in redundancy covers this case very well from system perspective, and even for a node operator recovering few megabytes of disk space is rarely worth the I/O necessary to perform the scan.
Sorry to hear that your drive has got read failure.
After you migrate all data you can from it, you can give it a few read/write passes using Spinrite (paid commercial program). I say after, because it takes a long time to scan entire drive using Spinrite. There may be some alternatives to this procedure (like zeroing, reading and repeating by hand), but none are that good, in my experience.
Right now, I suggest migrating all data as soon as possible, to keep your storj node online on a good drive. No point continuing serving storj from bad drive, it may get worse and corrupt more data. Just shut it down and start copying everything. You don’t get disqualified for many days (up to weeks, I don’t know exactly but I am sure someone here in the forums can say how long), so you have plenty of time to migrate everything.
Why not? On the contrary, Storagenode is the perfect use case to keep using bad drive, and thus prolong its useful life. Few gigabytes of bad data won’t have any impact on the storagenode. This is not true in literally any other conceivable usecase.
If that was, against all advice, a dedicated storj drive — I would continue running it.
Sending it back to get erased and recertified would result in too much carbon emissions and is 100% unnecessary. If the disk spins up — keep using it.
Very interesting point of view, thanks for sharing. Definitely worth considering for OP.
Rather than sending it somewhere, I was thinking of migrating data out, and then fixing it, before deploying again in storj. Fixing bad sectors is possible with software I mentioned earlier. But there’s no guarantee that bad sectors will not start growing in other areas, of course.
It’s not necessary after we implemented an autoupdater inside the container. However, the base image still can be updated (to take the security updates from the upstream). So it’s better to use it.
Because it need to audit millions of pieces for the same price as a repair (if it ever would be triggered, the customer may just delete their data before the number of the healthy pieces would fall below the repair threshold). The satellite is doing a random pieces audits from random nodes, if it would spent all its time for the one node - it’s too expensive. It’s better to disqualify your node if the audit score would fall below 97%. Much more cheaper.
It’s not. The work is done by the satellite. It must extract pieces from the segments and filter them by your node and do so millions times (how much pieces on your node? it contain only one piece from 80 for each segment). It almost never doing so, it works with segments, not pieces. It requests an audit for the segment (so, to several nodes), see a difference? Yes, the audit workers will finally ask for exact pieces, but they are a distributed service (after the distributed satellite), so they can allow themselves to do so. Even they do not audit each piece in the segment, only the required minimum to understand, is the segment still healthy or need to be repaired?
This does not make sense on so many levels… starting from the fact that chia, as a bunch of others cryptographic currencies, is just glorified gambling, while chia also wastes resources keeping disks occupied with garbage nobody wants and resulting in more disks produced and used. And gambling in any form is far from being “amazing” in any context. And besides, chia definitely has audits. Otherwise people could blackhole the data.
FYI: SMART tests only run when the drive is idle. In storj, the drive is never idle, therefore we can deduce that a long SMART test on a big drive will never finish.
Disclaimer: Never = before the next drive poweroff, ie host system restart due to OS updates.
This is not accurate. Smart test will use spare IOPS. Stoj produces minuscular IOPS, like 20-30, and the remaining 200-300 are available to run the self-test. Disks have massive processors, firmware developers figured out load balancing. But this is moot point because there is no reason to run these tests in the first place.
Responding to the comment I missed earlier:
Smart test does not fix anything. It’s a reporting tool.
Why? What if under your normal use they are not growing but when reading the whole surface 10 time they do? Will you keep the disk? Your filesystem can scrub, use that. Unlike smart surface scan, filesystem scrub can actually repair data. This is its purpose. SMART can’t predict drive failure. Crystal ball hasn’t been invented yet. If drive can read and write data – use it. If it does not – replace it. It does not matter what SMART says. It’s not a rocket science.
This is 100% waste of electricity and performance. When you encounter them with actual data – then the filesystem will fix it. Which should be during your monthly filesystem scrub.
No.
A drive has 200-300 IOPS. A SMART test will be paused for a very short time (ms) when even 1 of those IOPS is used. The drive will only continue the SMART test when the IOPS are at zero (for those few ms).
Even though we all miss that guy that kept asking for sources, here it is, straight from the smartctl manual:
selftest - [SCSI] the self-test log for a SCSI device has a slightly different format than for an ATA device. For each of the most recent twenty self-tests, it shows the type of test and the status (final or in progress) of the test. SCSI standards use the terms "foreground" and "background" (**rather than ATA's corresponding** "captive" and "**off-line**") and "short" and "**long**" (rather than ATA's corresponding "short" and "extended") to describe the type of the test.
The test we are talking about (per the quote above) is the ATA offline extended test. See below:
The second category of testing is called "offline" testing. This type of test can, in principle, degrade the device performance. The '-o on' option causes this offline testing to be carried out, automatically, on a regular scheduled basis. Normally, the disk will suspend offline testing while disk accesses are taking place, and then automatically resume it when the disk would otherwise be idle, so in practice it has little effect. Note that a one-time offline test can also be carried out immediately upon receipt of a user command. See the '-t offline' option below, which causes a one-time offline test to be carried out immediately.
Wrong. SMART tests can trigger the drive to reallocate bad sectors when detected. While it doesn’t physically repair anything, it does fix the issue by marking bad sectors and moving data to spare ones. It’s not just a reporting tool.
Well, okay, this is about storj. But from a hard disk’s perspective, chia is even more low load and balky disk tolerant. And yeah, it’s crypto, and has very little real world use, but it used to generate significant revenue from drives, and can still generate a teeny tiny bit.
The load on a chia drive is, really, almost nothing. It looks like 0% on a performance monitor. once in a while the sytem will look up data on one particular file that’s it. most of the used data is cached metadata.
the only time a file is “audited” is if it passes a filter check, then it’s integrity is checked to see if it win’s a block. This is a very rare occurrence (happened to me 3 times over years with a tiny farm).;;;;;;;;;;;;;;;;;;;;
any given chia plot is disposable, and they are fungible. if a file is corrupt, you can delete it and create a new plot in available disk space.
the first two drives I ever used for chia were two failing drives that had several thousand bad sectors each. And they worked fine. I only retired them when I either ran out of ports completely or they became uneconomical to run due to electricity cost.
You just literally described the algorithm the firmware uses to only utilize available IOPS; and now is this a counter argument?
Single backtick ` is “preformatted text”. You wanted “quotation”, it’s this symbol >. I can’t scroll for half an hour to read that.
These are counters with thresholds. 10 failures good. 100 failures — pre-fail. 200 failures — failed. And yet, disk is perfectly usable, minus those 200 failures.
These won’t tell you whether those failures will stabilize or avalanche tomorrow. Specifically because crystal ball wasn’t invented. Smart is useless.
If we start analyzing nicks — what does yours say about you? Could not take two seconds to write two words, had to throw a cat on a keyboard? Poor animal.
I didn’t actually: what you are saying I said: “if the drive uses 1 out of the 200 IOPS, the other 199 will go to SMART test.”
What I (and the smartctl manual) actually said: As long as there is ANY activity on the drive (ie either 1 out of the 200 IOPS, or 200 out of the 200 IOPS) THERE IS NO SMART TEST BEING RUN WITH THE REMAINING IOPS. The drive’s IOPS MUST be at 0 for some time (a few ms) in order for the SMART test to continue.
My random, cat-generated nick is untied from my personality, unlike yours it seems, it describes you well, to the degree that my previous post has been flagged and hidden because it hurt someone’s feelings.
My random, cat-generated nick is untied from my personality, unlike yours it seems, it describes you well, to the degree that my previous post has been flagged and hidden because it hurt someone’s feelings.