Re: Memory requirements, 3GB cache

In Squid's mailing list, on Sat, 27 Jul 1996, Ong Beng Hui wrote:

> > well, i've been testing with 34GB of disk, but that is only testing.
> > Mainly trying to get a feel for the best combination of stripes/multiple
> > cache directories. The striping is winning, and with the modifications
> > for cache dir structure in 1.1 would be better yet.
>
> Do you have any stats on that ? Like for instance,
> how much faster, how do you go about stripping the
> disks ?
>
> I am using Harvest Cache V2 and I am using a DEC 4100
> here with 3 channel RAID card. I am trying to test
> the performance without stripping.
>
> Our production machine here is also a DEC 4100 and
> we strip 3 disks with just 2 SCSI channel. Performance
> is okay with 1 million plus hit per day.

The options are:

1. 1.0.x's 100 dir or 1.1.x's 16*256 dir
2. single or multiple cache partitions
3. JBOD or RAID0

3. if jbod, there's no guarantee requests will not converge onto a
   single disk, even if you use multiple cache dir and 1.1's 16*256
   dir. => you've _NO_ control which disks requests land on. you would
   like stripping on the (scsi) block level, not on a per-file (JBOD)
   basis.
2. if RAID0 is the answer to #3, you'll want single cache partition.
1. regardless of what you choose for #2, #3, many files on a single
   dir is going to slow down your OS.

hence,

1. 1.1.x's 16*256 dir
2. single cache partition
3. RAID0

btw, your production machine is (3|4|5)0 GB big and only 3 disks?
each disk must be 9GB huge. RAID0 won't like these beasts, it
prefers many small ones.

---
Ivan Leong  <ivanl@pacific.net.sg>     the power to move
Systems Engineer, Pacific Internet     http://ilsp.pacific.net.sg