Labels

seedbox (8) bittorrent (7) dedicated server (6) traffic (6) 1gbps (5) rtorrent (5) unmetered (5) bandwidth (4) networking (4) resources (4) 10gbps (3) dedicated seedbox (3) hosting (3) provider (3) rutorrent (3) server admin (3) 100mbps (2) 100tb server (2) copyright (2) dediseedbox (2) peering (2) routing (2) unmetered server (2) adaptec (1) atom (1) autodl-irssi (1) btier (1) cogent (1) comcast (1) congestion (1) datacenter (1) dell (1) deluge (1) disks (1) disruptive (1) dmca (1) doge (1) downbox (1) failure (1) funny (1) hardware (1) howto (1) intel xeon (1) iops (1) irssi (1) kimsufi (1) linux (1) lsi (1) network neutrality (1) promise (1) raid (1) ram (1) rocketraid (1) security (1) software (1) ssd (1) ssd caching (1) storage (1) transmission (1) unlimited server (1) verizon (1) videos (1) webhosting (1) zfs (1)
Showing posts with label server admin. Show all posts
Showing posts with label server admin. Show all posts

12/21/2014

Benefits of a dedicated server

Wondering why you should get a dedicated server instead of shared hosting?
No matter is it seedbox, webhosting etc. but the same benefits stands for dedicated servers, if you can afford that little bit of extra. So let's take a look at them, shall we? :)

Performance, Power

You will gain stable high performance and processing power. Shared services usually have much higher markup and operate on much stronger servers, but also a huge amount of users in case of webhosting.

You will have the CPU, RAM and Disks just for you. In some cases you can even choose emphasis on CPU, Ram or Disks depending upon your particular needs.

Flexibility

On a Dedicated server you can run whatever software you please and are capable of installing and configuring yourself, even obscure little pieces of software.
You can even share your dedicated server if you have the skills to make the shared environment to share the costs of a such server.

Security

No other users sharing the disks, only the software running you choose to: This usually translates into less potential attack vectors, however, you need to make sure your server is secure yourself, but potentially a dedicated server is much more secure if you put in the right tools, keep it updated etc.

Ping and SSH Port

Oh one more thing, changing SSH port and disabling Ping is not security, it's a nuisance and annoyance to the support team, and will slow your support requests, create additional work for the support team, and provides barely no additional security what-so-ever. Any even semi capable hacker will know how to scan for alive hosts without Ping and find the SSH port very trivially with barely no slowdown. Plus if you run a webserver - everyone will know the node is up - so what's the point?
Don't do. Breaking standards and annoying your provider is not worth the 5secs of slowdown a potential attacker will have to find these out in any case.

9/10/2014

Storage software, hardware - the whole industry: It's bullshit

Storage industry changes the idiom: Lies, damn lies and statistics to something new: Lies, damn lies and Storage Industry!

Tbh i would trust more a sleezy sub-1000$ used car dealer than the storage industry after dabbling into for my work into the big storage field. Just some pointers here:

ZFS:
Intermittent hardware failure is almost guaranteed to nuke your data, ZFS never goes to read only mode for one.
Performance sucks, it's the worst design in regards of performance - UNLESS - you need single user sequential. In RAIDZ a single read will usually activate *all* drives in the vdev, seriously, ALL drives? It ruins the IOPS completely. Your other choice is mirroring - which will still remove half of your storage and half of your performance.
Don't believe the lies, ZFS is not the golden bullet solve-it-all, it's pure lies when they say that ZFS outperforms everything and anything - it doesn't because it lacks the IOPS capability.
For sequential one user at a time access it does have huge performance tho, so if that's your usage and you don't mind risking your data - go with it!
ZFS has good SSD caching tho, it's extremely effective. Problem is that it takes weeks to warm up in any sensible capacity. Weeks upon weeks. Yes, it really takes that long to warm. Tho, once it is warm, it does provide the most common data immensively fast.
So ZFS does have it PROs too! :) But for a multi-user setup? If you can handle the loss of IOPS and data risk you might be able to use it.

Older Adaptec Cards, couple gens old:
It seems almost like it has a timer, more time passed since release, more the card "sleeps". Original reviews of the cards gave brilliant reviews and performance, with many years more modern drives today the cards didn't even reach half of the performance from the reviews from release time. Card was SATA II capable.

SATA II Promise cards:
Drive fails? Sorry no go, your system won't boot up and you cannot diagnose the issue. Please try to guess which drive failed.
Further, in JBOD mode you cannot even get serial of a drive in any normal method.

RocketRAID, LSI MegaRaid + Newer AMD FX CPU / Chipset
RocketRaids loose connection to drives every now and then with no reason, not sure if this happens on Intel motherboards as well.
LSI MegaRaid won't let the system boot with Udevd modprobe kill timeouts. Apparently this happens only with newer AMD FX platforms.

Legacy RAID:
Way way too slow recheck, resync times, lacks flexibility etc. for today's huge drives. Otherwise very stable tho, decent performance.

Btier:
Nukes data, corrupting the OS if you have very high load, i would assume a block move from tier to another fails?
This same happens if you try to manually move A LOT of blocks from tier to tier.
Very nice idea tho, just needs some more work.

SSD Caching:
All the usual methods, Flashcache, EnhanceIO etc. sucks and bad, you are lucky to get 2 magnetic drives worth of performance from your expensive SSD cache. It's better to just get more magnetic drives for that array, and use the SSDs completely separately.
All assume you have infinite write speed, and eventually the SSD Cache will work as a SSD Bottleneck, way to solve it is secure erase the SSD and then re-enable caching.

SSDs:
Still need to provision 15%+ of space to sit empty for firmware to handle wear leveling, trim etc. discreetly on the background. Firmwares have huge differences, one SSD might need 25%+ and other is fine with 5%+ for this purpose.
Trim/Discard in many SSD cache packages doesn't actually work.
They also fail. They fail a lot. Infact, just don't use them, ok??
If you plan to use them in any other scenario than traditional disk / raid, they tend to fail super quickly.
As a single desktop drive, or perhaps RAID0 on a server or even RAID5 they work insanely well tho. Haven't tested as journal only device tho.

7/14/2014

Minimizing last gen Dell server power consumption

I got my hands on a used Dell cloud chassis with 4x nodes with 2xQC Intel Xeon CPUs each and 24G ram on each, for total of 96G.

Initially, when first time booting up it consumed 1050-1200W out of the wall. That's insane!
Fans were screaming like hurricane etc.

After a little bit of fiddling, slotting the nodes out and back in again, it stabilized to 690W under 100% CPU load finally. This is still way too much.

No power saving setting in BIOS seemed to help at all. Linux speedstepping was a bit erratic as well.

Took out the 2nd cpu was in my use those are not needed and slotted out half of the ram as well which was dedicated to the 2nd cpu and finally down to 320W under load, measured from the wall!

Now that is sweet: 320W for 4xXeon servers with 12G ECC Ram on each :)