SGI: Discussion

I kind of like the Seagate Cheetah 15K series. I'm only using the 15K.3, 15k.4 and 15K.5 series. They have FD bearings are aren't louder than a consumer SATA disk.

I know others (Ian M. ?) like Maxtor disks.

I'm also a fan of these drives
They can be bought quite cheaply on eBay as well (a while ago I got two used 15K.3 drives for £20 shipped).

^ ^^ Do you guys use your Fuels much ? Mine used to do this little trick that made me poop my pants every time : for no apparent reason the scsi root disk (I forget the brand) would go away. This would happen while it was running. It would not reboot, could not find the disk, etc etc.

You can imagine this was not pleasant.

I discovered that all I had to do was turn the machine off, connect the drive to a different header thingy on the cable, and reboot. It was then fine. It would run happily for a random amount of time between two days and six months then decide to do that again. Plug the drive back into the original socket, it was again fine.

Changed the cable. Same behavior.

The only thing I can think is that the cables on those things are really bad ? But even that doesn't seem to be a good answer.

Other than that the Fuel was reliable but ... talk about dirty underwear

I haven't had this happen to me (*knock on wood*), although sometimes the root drive made the case resonate (really annoying sound), but that went away after I moved it to another slot

Yeah I'm a big fan of the Maxtor Atlas II 15k series, just make sure you get the Atlas II series, much quieter and a little bit faster. I've picked up 73gb drives for $20-$25 off eBay, the 146gb drives are the harder to find for that price point.

I managed to grab an 800MHz CPU and 4GB of RAM to upgrade my Fuel but wasnt able to locate suitable SCSI drives.

I was looking around locally to try and find the drives instead of ordering on eBay. Its alot harder than I was expecting.. Found a bunch of SCA 80pin drives which I picked up for future but no one had 50pin or 68pin.

Yesterday, I found 2 of the Cheetah 15k drives and 2 Atlas II drives which are on order and should be arriving in a few days. Once those arrive I can finally start to setup the computer and install IRIX on it.

Thanks to all of you for your suggestions.

I think my Indigo2 IMPACT might be up for grabs soon.

Adapters that attach to the 80-pin SCA interface and provide a 68-pin SCSI interface are usually not to hard to come by. Here's one (for $3) from the top of a google search - I'm sure you can find others....
http://www.amazon.com/Sca-Ultra-Scsi-Lv ... 36-4228154

I did find those but held of on resorting to them unless I couldnt locate the native 68pin drives. I'd rather not have the extra electronics in there if I dont need them.

If you have other SGI machines, the 80 pin drives with an adapter are more versatile. With 80 pin drives you can swap them into an O2 or Octane very easily for various purposes. A 68 pin drive can't do that.

An 80 pin data drive running xfs could be used in a Linux box as well. If it's a server-style computer it will have 80 pin sockets. It's easy to put an adapter on an 80 pin drive for a 68 pin cable but difficult to fit that setup into a computer intended for use with sca drives.

The electronics are less than minimal. It's a couple of chips and two connectors and there's plenty of room for them inside the Fuel case. Not so in the other direction.

It's actually just a passive converter (two connectors and a PCB), so there's no reason not to use one

I have a cheap $2 one from China in my Fuel and it works great.

I go SCA and an adapter pretty much all the time now. Used SCA drives are very cheap and pretty new, and you can get the "universal" 50/68 -> SCA adapters that will allow you to move your drives to almost any machine. Older versions of IRIX won't always read newer versions of XFS, but you can use EFS or even tar to the device for a fast file transfer. Also works for IRIX installs.

Your cables are more likely to fail than the adapter.

Mine has a resistor. That's probably why it was $3

Ahh.. so there isn't much electronics that could fail... I try to keep things as simple as possible to reduce points of failure. I have a few 68pin and 80pin drives for now but at least I know I can resort to these instead of procuring more 68pin HDs.

$1 for a resistor, that's a ripoff !

Careful on the models, some drives are "more" server-oriented and have features that make deskside installation unpleasant (unles you enjoy screeching noise every couple seconds):

http://forums.nekochan.net/viewtopic.php?f=3&t=16726200

I just checked and mine has a pull-up resistor too, you got ripped off


You can actually turn that off if you have a PC that can run the Seagate tools (or whatever that software is called nowadays). The firmware is the same on all drives, there are just special user-settable flags, which tell it which mode to work in.

It should be possible to change those flags from IRIX as well, but you'll have to mess around with some low-level tools and spend some time reading the drive documentation to find which bits you have to change (I love it how SCSI drive manufacturers put _everything_ in the manual).

White face tax Sometimes I am just too lazy to bargain.

There's was a sub-reddit for most other operating systems, Irix was missing, so i created one: http://www.reddit.com/r/irix - Now we are no longer under-represented - added links to nekochan.

great

An older post, but...




Ahh that's a distant memory. I guess you must be thinking of way back when I had a Maxtor Atlas 15K II 147GB as my Fuel's
system disk. Was nice, but I upgraded later to a Fujitsu 300GB 15K which was even quicker, but now my Fuel/900 has the system
disk split across a 60GB SSD in an ARS-2160 bridge box, and a 120GB SSD connected to an LSI SAS3442X-R card, so all
accesses to /var and /usr are waaaay quicker than any of the SCSI disks (which includes all user account files, though my 'ian'
account is on its own 120GB SSD anyway):



Access speed to the root file system is also much quicker than a SCSI disk for small request size random I/O, which is
the limiting factor for general responsiveness, though the max sequential I/O is limited by various factors (but not that
relevant since most accesses are to /usr and /var anyway):



4K random read is 15X faster than the quickest SCSI disk I've tested so far (Fujitsu MAX 36GB 15K).


But jan-jaap is right, the later Seagate 15Ks are nice overall, inparticular the ST3146855LC. However, other disks are
much the same, while for storing general data there are much better SAS options such as the Seagate 15K.7 (ST3600857SS)
which can do more than 200MB/sec sequential I/O.

See my Fuel hinv for updated details re the SSDs.

Ian.

PS. jan-jaap, I've standardised now on the Fujitsu MAX3036NC for system disks in Octane, and the MAS3367NC for O2
and Fuel. Both are pretty quiet, but the MAS inparticular makes very little noise, ideal for O2 and Fuel. My gateway O2
(modded PSU fan) has a MAS installed; but for the green LED I wouldn't know it was even turned on.