[weblacky]

Hi All,
   I recently got in a pair of S25CF - Adtron Corporation drives, these are slower (1999-ish) DUAL CF -> 50 pin 2.5" SCSI drives.  I've now gotten the 2mm to 2.54mm 50 pin breakout adapters and am working my way up to trying to test them for install on the upcoming refresh of an Indy & Indigo.    No one knows just how fast they are, but I know they aren't faster than 10MiB/s, likely slower to around 5MiB/s.  Anyway, I've just ordered used, older, SanDisk Ultra II CF cards that *SHOULD* work but it's a gamble....more on all that later.

Anyway to prepare for this (and possibly other SSD-style mods).  I was hoping for any info about optimizations for SSDs on SGIs (both under XFS and Irix setup).  Like:

1. Removal of swap space entirely (Indy has MAX 256MB already installed) or at least swap space on a secondary mechanical drive and NOT on an SSD (during Irix setup and operation).
   
2. Possible filesystem mount options like "don't record file last access dates" or some such things to speed up file systems operations on slow drives.
   
3. Volume alignment tricks, can we do anything inside FX to push entire partition creation to be aligned to 2KiB or such boundaries?
   
4. XFS cluster size being a correct multiple of NAND, assuming 2KiB for now until I know more.
   

I have OTHER SGIs/Linux that can access SCSI drives so if these operations cannot be done during install, I can always prep a drive on another machine (to skip the FX stage on a new machine) to put specific XFS cluster values and the like on a drive before OS installation.  I know Linux can read (possibly create?) SGI volume partition schemes.  So if the ENTIRE partition scheme needs to be setup on Linux to be aligned, then placed in a running Irix machine to format XFS V1 or V2, I can do that!

Anything else I might not know?

So, Info?  Please post what you got, I'd like to at least have this be a good place to establish SSD practices to get as much speed as possible from SSD/SD/CF SCSI solutions.

Thanks!

[Raion]

1. Yeah, I'd pull swap off the drive. SCSI2SD users I know still use swap though, so YMMV.
2. you should be able to set those in /etc/fstab. noatime is one that's usually recommended on SSDs and such.
3. no idea
4. No idea.

[weblacky]

Reading the Irix docs it looks like you have to have a swap partition on the root drive. However you can add additional swaps (files or partitions) with different priorities and possibly even turn off the root swap as a boot script when you have alternative swaps.

So it may be possible to de-prioritize the root swap enough to not really use it or turn it off after boot. But yeah, the kernel itself is rigid and according to the install docs will demand a swap partition with the expected ID.

The swap command claims there is a reset as well, so I guess one could auto-setup a new swap space during boot, then reset to default in shutdown?

Unknown for now but that looks like a hard requirement for now.

[josehill]

Reading the Irix docs it looks like you have to have a swap partition on the root drive.

I'm not sure that's correct, at least for Irix 6.5.x.

Granted, it's been 15 years since I touched the system, but I'm almost completely certain that I had configured an Origin 2800 to use a dedicated (non-root) hard drive as primary swap.

[weblacky]

Page #6: http://irix7.com/techpubs/007-2825-013.pdf

"System disks contain the IRIX operating system. Specifically, they must contain a volume
header that includes sash (see “Volume Headers” on page 12),the root filesystem, a
swap partition, and possibly a usr filesystem"

While I'm not 100%, the installer for Irix will look for the swap on partition(1) of root drive and error if t doesn't find one. I'm unsure if (during install) you can have a swap on another drive while NOT having a swap partition on the root disk. I know you can add swaps later, but I'm uncertain if you can install it like that (wasted space now, unused swap).

I was asking if you can literally NOT have the swap partition on the SSD and only somewhere else while installing Irix. I don't think you can, I hope to be proven wrong.

However I know I can steer the swap to another drive once Irix is running and functioning. But then trying to reclaim the swap partition of the root drive for the root partition would be hard.

[robespierre]

A swap partition is required to run the miniroot inst (since it is where the miniroot runs from). But it does not necessarily need to be on the same drive to which IRIX is installed. inst is very configurable and its target partition can be changed to a different physical disk.
I believe you can also run inst as a normal program (from IRIX) to install the system on a different disk (not the root disk which would be busy).

If you are limited for some reason to a single (writable) disk, you cannot use the above methods.

[josehill]

I was asking if you can literally NOT have the swap partition on the SSD and only somewhere else while installing Irix.  I don't think you can, I hope to be proven wrong.

Hmm. I wish I still had my old system notebook to look up how I configured that system. I suppose it's possible that the original setup was as a standard root drive (s0 = root, s1 = swap), but then I configured a second drive to mount at /dev/swap, leaving the original s1 present, but not mounted/used. In that case, the root drive's slice 1 would be available for miniroot installations, even if it wasn't used during routine operations or live installations. I would have set that particular system up ~20 years ago (OMG!), so the memory is hazy.