RAID 1 failure

[stek]

Several years ago I was converting a bunch of AIFF files to MP3 and found that my VMS Alpha system running on a U320 SCSI was about 3 times the speed of my iBook running on a Firewire 400 drive. Same version of same program, same CPU clock speed on both systems, and as near as makes no difference same CPU consumed on both platforms.

Everything else on the Mac slowed to a crawl, but on the VMS box, the desktop felt just as snappy as on an empty system. At the time my conclusion was that VMS has a better process scheduler. I suspect you are seeing the same with AIX.

With a pile of CDs to get onto my iPod, it was a no brainer which system I used for the MP3 conversion.

Think it's because the SCSI controller is relieving the CPU of I/O related tasks and maybe because even the Mac now is basically a PC (is it?) - these high end Unix/Alpha/MIPS systems have been designed with stonking great buses to shift data about and no fecking IRQs. For me that's why I don't think Linux will ever replace the true mission-critical back-end environment, not so much Linux itself, just the servers are basically PC's.

Ten years ago I had an SGI 02 - it had unified memory, and it could do full screen video at stonking framerates, and it was old then. I miss it - the old Toaster, but the build quality was so bad - one day it fried itself

[doodab]

Think it's because the SCSI controller is relieving the CPU of I/O related tasks and maybe because even the Mac now is basically a PC (is it?) - these high end Unix/Alpha/MIPS systems have been designed with stonking great buses to shift data about and no fecking IRQs. For me that's why I don't think Linux will ever replace the true mission-critical back-end environment, not so much Linux itself, just the servers are basically PC's.

Ten years ago I had an SGI 02 - it had unified memory, and it could do full screen video at stonking framerates, and it was old then. I miss it - the old Toaster, but the build quality was so bad - one day it fried itself

Also worth remembering that the SCSI disks are probably 10k or 15k RPM, that firewire 400 drive is at best 7.2k and maybe as slow as 5.4k RPM and the 1394 bus throughput is limited to 45-50MB/s or so.

A high end modern PC (or mac) has stonking memory and IO bandwidth though, even compared to the dream machines of yesteryear.

[Sysman]

]

Think it's because the SCSI controller is relieving the CPU of I/O related tasks and maybe because even the Mac now is basically a PC (is it?) - these high end Unix/Alpha/MIPS systems have been designed with stonking great buses to shift data about and no fecking IRQs. For me that's why I don't think Linux will ever replace the true mission-critical back-end environment, not so much Linux itself, just the servers are basically PC's.

I do miss those high end systems for sustained heavy I/O loads. On the Linux side I came across a serious performance problem this week with Ubuntu 10.10, so bad that I was on the point of going back to Windows and just lobbing hardware at the issue:

Script To Automatically Apply the "200 Lines Kernel Patch" Alternative In Ubuntu
background at Ubuntu bugs: Heavy Disk I/O harms desktop responsiveness

I applied this yesterday and it really does work. This also explains why I wasn't seeing this behaviour under Linux Mint, for Mint 10 already has that patch (Mint didn't quite suit the requirements for what I am doing at the moment).

Other reading has given me the impression that the Linux crowd, for all their hard work and good ideas, don't really understand hefty I/O - see my file systems thread for a link to arguments within the Linux community. I suspect that this is an area where the Enterprise editions do better though.

Ten years ago I had an SGI 02 - it had unified memory, and it could do full screen video at stonking framerates, and it was old then. I miss it - the old Toaster, but the build quality was so bad - one day it fried itself

In contrast the engineering on DEC kit was outstanding. I once saw a PDP literally scorched by an aircon failure and once cooled down it still booted up. But as history tells us, no marketing and too expensive.

[stek]

In contrast the engineering on DEC kit was outstanding. I once saw a PDP literally scorched by an aircon failure and once cooled down it still booted up. But as history tells us, no marketing and too expensive.

To be fair to SGI I still have an Octane 2, only a small squat box, but weights a ton, made from cast iron almost! Also have an SGI Fuel, PC-quality, noisy in a cheapo-type way, whereas the Octane hums nicely.

Best of all is the IBM Intellistation 285, RS6000, really heavy, arrived on pallet, totally fast though, at least twice as fast as the Sun Ultra 45 I also have.

Geektastic or what!

[VectraMan]

I've got two currently and am planning on building another. I've got a LVM with six partitions sitting on top of the RAID 5 as well. What went wrong in your case?

I was trying to install Ubuntu, but the regular install wouldn't recognise the system, but there's a different more manual install I had to use followed by lots of terrifying command line stuff to install an "experimental" driver for the RAID. That worked, but the intention was to dual boot with Windows and with both on there I absolutely could not get the loader to boot into Linux (Windows 7 worked fine). I even posted on the Ubuntu forums, and got zero replies.

In the end I gave up, and wondered why I was bothering with Linux in the first place.

[Sysman]

To be fair to SGI I still have an Octane 2, only a small squat box, but weights a ton, made from cast iron almost! Also have an SGI Fuel, PC-quality, noisy in a cheapo-type way, whereas the Octane hums nicely.

Best of all is the IBM Intellistation 285, RS6000, really heavy, arrived on pallet, totally fast though, at least twice as fast as the Sun Ultra 45 I also have.

Geektastic or what!

Somebody has to do it. In hindsight I'm glad I didn't put an offer in for a pair of Vaxes which were palleted up. The decider was that my office at the time was on the fourth floor

[Sysman]

I was trying to install Ubuntu, but the regular install wouldn't recognise the system, but there's a different more manual install I had to use followed by lots of terrifying command line stuff to install an "experimental" driver for the RAID. That worked, but the intention was to dual boot with Windows and with both on there I absolutely could not get the loader to boot into Linux (Windows 7 worked fine). I even posted on the Ubuntu forums, and got zero replies.

Too many of these Linux distros seem to assume that you only have one disk and that if you already have Windows on your system you want to shrink that partition and put Linux alongside. The Ubuntu Alternative Download gets past this but can be tediously complicated - if you want to do something non-standard, you have to specify everything else as well. I got away with a simpler mode which allowed me to specify LVM.

In the end I gave up, and wondered why I was bothering with Linux in the first place.

To round out my CV is one answer. That I prefer command line control over point and click methods for a lot of stuff is another.

[escapeUK]

gets past this but can be tediously complicated - if you want to do something non-standard, you have to
specify everything else as well.

Ive always said, its only free if your time is worth nothing.

[Sysman]

Ive always said, its only free if your time is worth nothing.

That's another snag with it - you keep coming across the Free Software zealots.

I really don't mind paying for software that is decent.

[lilelvis2000]

I was trying to install Ubuntu, but the regular install wouldn't recognise the system, but there's a different more manual install I had to use followed by lots of terrifying command line stuff to install an "experimental" driver for the RAID. That worked, but the intention was to dual boot with Windows and with both on there I absolutely could not get the loader to boot into Linux (Windows 7 worked fine). I even posted on the Ubuntu forums, and got zero replies.

In the end I gave up, and wondered why I was bothering with Linux in the first place.

Oh if you are trying to dual boot WIndows an Linux and also share the RAID I'd say you'll be in for a rough ride. You'd be better virtualising Windows inside Linux and sharing NFS mounts as drives in the WIndows Instance.

I used Linux because I didn't have much cash t fork out for SBS and I wasn't interested in Exchange anyway. So I have a Samba PDC, e-mail server in smarthost mode, LDAP, CUPS, WebDAV and webmail. It took some time but I have had plenty of that on my hands recently.