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Comment: Re:How powered off is "powered off"? (Score 4, Interesting) 184

by dshk (#49657239) Attached to: Enterprise SSDs, Powered Off, Potentially Lose Data In a Week
You may be right in case of other equipment, but enterprise grade drives are really better. For example I do not know any consumer SSD which has power loss capacitors (Intel 320 is not produced anymore). Most consumer drives don't contain even those capacitors which would be necessary to prevent the loss of - not the freshly written but the - old(!) data in case of a power loss. Consumer HDDs lied (or lying?) about sync, they confirm sync before they actually save the data to disk. And I am sure that consumer SSDs do something similar, because consumer SSD are usually faster (although their speed frequently fluctuates to extreme extents) than their corresponding enterprise variants, which is impossible in a safe way without power loss protection capacitors.

Comment: What it really says... (Score 5, Interesting) 184

by dshk (#49657151) Attached to: Enterprise SSDs, Powered Off, Potentially Lose Data In a Week

The relevant table is on 27. page.

In short: if you use the SSD in a cold environment AND store it in hot environment than you may lose data quite quickly. Quicker than two weeks.

Client drives are also affected, but the data loss occurs slighly later. I guess reason of the difference is that enerprise drives assume a higher work temperature.

So the advice is that if you use the SSD in your air conditioned basement in a good case then do not store your SSD on the sun for extended periods.

And no, I do not use spinning media as a backup. I use tapes. Using spinning media for proper backups is almost impossible. See

Comment: toy anyway (Score 1, Interesting) 65

by dshk (#49654873) Attached to: Samsung's SSD 840 Read Performance Degradation Explained
It has no power loss protection, so now it could lose data much faster. It should be good for worthless data but that is all. I am not sure if it has at least small capacitors, the half-assed power loss mitigation technique which does not protect new flushed data, but at least prevents the loss of old, unrelated data.

Comment: Re:Where is the support for ECC RAM? (Score 3, Informative) 166

by dshk (#49636507) Attached to: AMD Outlines Plans For Zen-Based Processors, First Due In 2016
What are you talking about? All AMD server boards support ECC. In contrast to Intel, AMD always puts every feature into every processor of the same generation. AMD does not dumb down artificially even its cheapest processor. That is one of the thing I like in AMD processors. I do not have to check which random feature is disabled in a particular processor. Even some desktop AMD motherboards have ECC support, like the SABERTOOTH 990FX.

Comment: Compared to tape (Score 1) 71

by dshk (#49246801) Attached to: Google Nearline Delivers Some Serious Competition To Amazon Glacier
I thought that our tape backup system is luxury, for such a small company. Quite the contrary, it seems that tape is very cheap. Back of the envelope calculation: Our daily full backup is about 600 gigabytes. We are using 6 pieces of LTO-3 tapes for the last days and 1 for each month, plus 1 for each year. That is about 23 tapes in use. Total of 23Ã--600GB is 13800GB, 138 dollar each month on Google Nearline, which is 1700$ per year. The total cost of the tape drive, the tapes and the SCSI adapter was less than 1700$. And I expect that to work for at least 5 years, not 1. That means that for backup tape is 80% cheaper. Of course deduplication would reduce the data amount to a few percentage of its current size. But then we would lose the plenty of redundancy we have with tapes. Google Nearline is offsite, that is good, or actually, that is required for backup. Offline copies are required too, and that is where the entire thing fails for this purpose. Google nearline is online storage from a backup point of view. In other words it cannot be used for backup. It can be part of a backup strategy, though. It could be good for saving backup copies of family photos, if the account password is managed very cautiously. Otherwise I do not see the use cases for this service, but I am sure there are some.

Comment: Re:Shyeah, right. (Score 1) 284

by dshk (#48472589) Attached to: Is LTO Tape On Its Way Out?
I moved to the opposite direction, from disks to tapes. We are a small IT company with less than 10 employees, mostly developers, no dedicated sysadmin, but quite a few servers. We had no previous experiences, so our backup "methodolody" is only slowly improving in ad-hoc ways. First we had backups of critical data stored on online disks. Source code and a very few other things. No configuration files, no database. There were only ad-hoc copies of the latters. After a while I started to backup more data, and started to use a centralized backup software (namely Bacula). Backups were still written to online disks. Everything was online, and we are reguralry attacked by hackers. Not a good combination. In the next step I tried to occassionally copy the online backups to offline disks. That did not really worked. Copyying all backups were time consuming, and I usually forgot it or do not have time for it. Large hard disks are still not that cheap, and they cannot be simply taken out the server and put back. The drives must be mounted on a tray, which require additional costs and work. Most people forget that if I have a 300 GB dataset, then I need about 30 * 300 GB backup space. There are tricks to reduce that, but that makes everything more difficult, more time consuming, less safe. I started to use tapes 2 years ago, after I recognized that our backup software supports that better. I thought that tape for us will always be a luxury, but it makes things much simpler. Equipment cost was definitely not a motivation. And indeed that is what happened, now everything is super simple. Bacula tells me what tape should I put into the drive, or if I need to buy a new tape. We have offline copies and multiples copies recorded at different dates. We can retrieve and compare data from 1 day ago, 2 days, one week, one month one yeat, whaterver I want. That is a nice safety, much-much better than we had previously. Bacause tapes are cheaper, I do not mind adding new data to backup and new tapes, just to make things simple. The funny thing is that I believe we shortly reach the point when our very simple, very safe, tape based backup system will be actually cheaper than the equal hard disk based, even if I do not count labour, only equipment. I am sure that a larger organization with real sysadmins can do it better, but I am quite happy with our current state.

Comment: Article is valid, answers are stupid (Score 2) 265

by dshk (#48132539) Attached to: Ask Slashdot: Why Can't Google Block Spam In Gmail?
The submitter does NOT complain about Google's ability to catch spam! He asks why Gmail does not REJECT obvious spam. Rejecting an email means that - in this case the Gmail - server does not even accept it. In such cases the sender gets back a Delivery Status Notification from his own server, telling him that his email did not go through because of such and such error. An important point here is that the email is not lost without any notification. The sender can try to contact the recipient in another way. Actually this may be better than putting the email into a spam folder if that is not monitored regularly, or at all. Yes, this is a valid question, but almost none have undersood it.

Comment: Re: it solves some unicode issues (Score 1) 774

by dshk (#48112243) Attached to: Systemd Adding Its Own Console To Linux Systems

I do not understand this complaint about unix configuration either. I am a relatively new Linux user (about 5 years, compared to 20 years on Windows), and I find the Unix configuration system is far-far better than the mess in Windows. Everything is in the /etc/ directory. In the rare cases when I install a tarball instead of a package, the configuration files are in /opt//conf. I manage about about 50 virtual servers, it really works well.

Text configuration files are easily managed by standard command line tools, including diffing and merging changes during upgrade, and non-interactive modifications.

Comment: Re:How quickly will they run back to Oracle? (Score 1) 198

by dshk (#47872385) Attached to: UK's National Health Service Moves To NoSQL Running On an Open-Source Stack

So, when you have an operation and they wind up performing a sex reassignment surgery instead of an appendectomy due to the lack of atomicity, consistency, isolation and durability in their database, you would be OK with it?

Demagogy. Your example has nothing to do with ACID. Such a case would inditate wrong data entry or a client software bug.

By the way, such errors do occur. Even in systems where the database is ACID.

I have not read the article, but I guess they store either very frequent data (measurements) in NoSQL, or large data (3D images). Depending on nonfunctional requirements, neither is possible at all, or cost-effective with RDBMS.

Comment: Re:No. (Score 1) 368

by dshk (#47871057) Attached to: Report: Microsoft To Buy Minecraft Studio For $2bn+
I haven't wanted to hurt anybody's feelings. We also have four Ubuntu desktops and two Ubuntu laptops in our house, including both old and current high-end machines. However, I believe it is quite unusual when it turns out that 15% of some group of teenagers uses Linux, and it must have some rational reason. I am sure that there are other reasons too, like my son's advocacy, but having old PCs are likely a reason.

Comment: Re:No. (Score 1) 368

by dshk (#47869955) Attached to: Report: Microsoft To Buy Minecraft Studio For $2bn+

I believe you make my point stronger by showing that even with such small resources and incompetent developers, it was possible to create the most moddable game (ever?). Without actually putting any effort into moddability... That made it possible to spend all of their limited resources on a good game design. That is not a small feat.

I worked in both C and Java for many years, and regarding moddability, no, it is not possible to beat Java using C with equal resources. My son's code regurly replace builtin Minecraft classes, runtime, without a significant effort, if the existing extension system does not provides (yet) the necessary hooks for him.

Comment: Re:Partial consistency is... inconsistency! (Score 2) 198

by dshk (#47869845) Attached to: UK's National Health Service Moves To NoSQL Running On an Open-Source Stack
I am a server side developer for 14 years on a single system. We use MySQL but still not its ACID table types. After so much time maybe I am in the position that I can state, that, no, most of our data does not require ACID. Even which would require it theoretically is doing fine after 14 years.

What we would indeed need, is the multi-datacenter capability. Which you get for free with Cassandra... We also sorely needed performance a few years ago (15k SAS drives was slow after an internet hiccup for example), but SSD drives helped in that. Again we could get infinite scalability with Cassandra for free.

You must choose in such a situation: either the - only theoretically needed - ACID, or the actually performing and highly available NoSQL with its additional operations, coding burden?

Don't panic.