Which CF disks for RaQ4

[sven]

Hello everybody,


for my RaQ4r I'm looking for two Compact Flash disks required for replacing the hard disk and an usb memory stick. Ok, I replaced the two 20 GB hard disks with a 10 GB one and abandon the security of raid.

The first CF disk should be the system disk and the second only for proxy caching space (addon update accelerator).
For the whole system, I think it will be sufficient to have a 2 GB or 4 GB disk, for update accelerator I think 8 GB would be rationally, thinking of costs and space disposition.

Now there are a pretty couple of CF disk types, speeds and manufacturers and I'm confused which to look for, e.g. Sandisk Ultra II, Extreme III or IV and so on.
To buy rationally, I don't like to "oversize" the card speed type, simply it should fit the RaQ4 IDE controller speed.

Are there some suggestions by someone here?
Thank you very much.


Kind regards,
Sven

[Davesworld]

If you want to use CF installs, don't even think about holding a large proxy cache. /var/log actually resides in the mounted ramdisk and the logs are backed up to a tarball in /var/log_compressed once an hour and on shutdown but the cache is NOT saved. With the default 64MB ramdisk size, any cache larger than 10MB is asking for trouble. I tried 5MB but it won't alllow such a low setting. I rarely use the proxy anyway and do not have it set transparent.

The CF images I provide here only differ from the standard IPCop in one way and that is that a standard IPCop flash image made from the mkflash script, uses an embedded rd (ramdisk filesystem) driver which is set up with grub as an argument. In a Cobalt, the bzipped kernel is started from the rom and given an argument to use ttyS0 as the console, changing this and adding to it is risky and more work than is necessary for most of us if it can even be done, so per Olaf's suggestion, I made the rd driver modular so we can also use the rd filesystem in a Cobalt by modprobing it with a command added to the init scripts. I chose rc.flash.up since the ramdisk is not needed or desired in a hard drive installation. The modprobe command also allows setting up the ramdisk size with an option added to it. This can be changed from the default 64MB I set in the rc.flash.up script to whatever one chooses. You can run up to a GB of ram in these since the newer roms are set up for it. The default 512MB max ram in the literature is no longer true with the newer 2.4 kernel roms that came about in 2004.

Now what you are talking about, would require a hard disk install of Raqcop and maybe an industrial grade CF flash could handle it without vaporizing the CF card in short order. I do use Transcend industrial grade 512MB flash drives. When using a UDMA capable CF to IDE adapter, I get more throughput than the stock 20GB Seagate OEM drive in my simple hdparm -t test. Simply put, there is no CF card you could likely buy for a reasonable amount that would best the Ali153x IDE controller of the 3000 series Raq and Qubes.

To sum up, the CF installs, both ours and the standard IPCop from mkflash, are set up to make the CF card last for years, I had heard 15 years running 24/7 but IPCop hasn't been around that long yet.

As a sidenote, anyone running a Raqcop on their Seagate or other HD, the stock IPCop mkflash script will work just fine as is in Raqcop as well. 128MB min and 4GB max even though anything over a GB is really a big waste. You end up with a huge root partition that has a little over 100MB worth of files on it. Of course you choose hda as the drive. mkflash 512 hda will spit out a 512MB image ready to run.

[sven]

Hello Dave,


oh, by the way, for using update accelerator I like to put the directory for the cache onto a separate disk and mount it to "/home/httpd/html/updatecache" (because I don't like to bend the ipcop's standard partitions design or putting the cache to "/var/log"). I've done this with my harddisk installation of raqcop too. Now, I'm using a USB stick (8 GB) and mount it to this mountpoint. In future, I like to do this with a CF card instead of this USB stick, because I think a CF card will have a higher throughput than an USB stick at RaQ USB port (isn't this port an USB 1.1?).

Never mind, at first I'm looking for a CF card for the basic install of ipcop / raqcop (and maybe I'm using the USB stick for placing the update accelerator cache some time longer; CF disks at this size or larger than 8 GB seems to be pretty expensive ).


It seems to be that there are a few steps to take.
First, I like to know what kind of CF card I should look for (e.g. Sandisk Ultra II, Extreme III or IV and so on) and what type fits to the RaQ4 IDE controller best.
Secondly, I like to know what size these CF Card should have. For now I think 2 or 4 GB should fit more than enough.
Thirdly, may a CF disk replace a USB stick? I think it may work, but it is the very last step in my plan.
(Fourthly, - ok, wasn't there a very last step? - I will take a look for 1 GB RAM replacing my RaQs 512 MB)


Do you have some suggestions for me?
I know, one fool can ask more questions than seven wise men can answer... 



Greetings
Sven

[weizen_42]

For an installation without Proxy and Update Accelerator 256/512 MB is sufficient.

Since the proxy (when activated) will run in RAM and RAM disk the only thing to watch out for is the size of RAM disk.
I've you've got the RAM, increase RAM disk size (for example 192 MB) and limit the Proxy disk usage to say 64 MB.

If you intend to run Update Accelerator on a seperate disk / CF card, 256/512 for the primary card are still sufficient.


PS: I use a DOM instead of CF card, same technology but saves the possibly cumbersome mechanical mounting of a IDE-CF adapter.

[Davesworld]

For an installation without Proxy and Update Accelerator 256/512 MB is sufficient.

Since the proxy (when activated) will run in RAM and RAM disk the only thing to watch out for is the size of RAM disk.
I've you've got the RAM, increase RAM disk size (for example 192 MB) and limit the Proxy disk usage to say 64 MB.

If you intend to run Update Accelerator on a seperate disk / CF card, 256/512 for the primary card are still sufficient.


PS: I use a DOM instead of CF card, same technology but saves the possibly cumbersome mechanical mounting of a IDE-CF adapter.

Are you using a cable for power? I think last time I checked, pin 20 had no power on a Raq3/4. Brian and I use Syba direct mount readers that we had to order online. Even so, I think I found a spot on the front panel that could be made into a CF slot. Spare bare chassis can be had here for cheap if I botch one up too bad.

[weizen_42]

Are you using a cable for power?

Yes.  512 MB DOM with standard IDE power connector. Can be mounted in both IDE1 and IDE2 connector, the height of a DOM is a perfect fit.

To the right you see the power cable, which came with an adapter to standard 4-pin power.

[Davesworld]

It looks like you have it in the secondary ide header. Did you have to set the root partition to hdb4? From what I have seen, those DOM units at that size can be had for less than the price of a pizza. In my main workstation, I have a Mitsumi multi reader that also doubles as a floppy drive so imaging to the CF cards is easy. Lets do some numbers here.

On a Raq with the 512MB Transcend industrial card in my picture I get:
root@testcop:~ # hdparm -Tt /dev/hda

/dev/hda:
 Timing cached reads:   102 MB in  2.02 seconds =  50.45 MB/sec
 Timing buffered disk reads:   58 MB in  3.03 seconds =  19.16 MB/sec

On a Raq with the OEM Seagate 20GB I get:

root@raqcop:~ # hdparm -Tt /dev/hda

/dev/hda:
 Timing cached reads:   188 MB in  2.02 seconds =  93.07 MB/sec
 Timing buffered disk reads:   54 MB in  3.10 seconds =  17.42 MB/sec

[sven]

Hello.

ok, means that, that I have to take a look for Sandisk Extreme IV (or better)?
AFAIK does Extreme IV 40 MB/s and more for read and write, Extreme III 20 MB/s and Ultra II 10 MB/s.


By the way, I'll have to take a look at my RaQ with hdparm...

...


Wow, mine does

Code:

# hdparm -Tt /dev/hda

/dev/hda:
 Timing cached reads:   216 MB in  2.03 seconds = 106.40 MB/sec
 Timing buffered disk reads:   64 MB in  3.04 seconds =  21.05 MB/sec

with its 10 GB IDE HD ST310212A (DMA is on)
and

Code:

# hdparm -Tt /dev/sda

/dev/sda:
 Timing cached reads:   216 MB in  2.03 seconds = 106.40 MB/sec
 Timing buffered disk reads:    4 MB in  4.33 seconds = 945.96 kB/sec

with its USB stick.

The USB stick seems to be a bottleneck and has to be removed when migrating from HD to CF...


For now, here a Sandisk Extreme IV 4 GB CF costs about 50 Euro, a 8 GB about 100 Euro. Pretty much money and I believe that the USB stick will reside in its place for the next time.

I'm not sure, but what will be the negative point for an IPCop, if the CF card(s) will not have more than 10 MB/s?
Here at home, I've got only a handful of PCs surfing around and if update accelerator cashes the patches and updates, only the first one does the updates at (low) internet speed.



Regards
Sven

[weizen_42]

It looks like you have it in the secondary ide header. Did you have to set the root partition to hdb4?

Sorry for confusion.  It is normally on primary ide.
The picture is just Proof of Concept that it is possible to use 2 DOMs 

My DOM:

Code:

root@raqcop:~ # hdparm -Tt /dev/hda

/dev/hda:
 Timing cached reads:   192 MB in  2.02 seconds =  95.05 MB/sec
 Timing buffered disk reads:   44 MB in  3.12 seconds =  14.10 MB/sec

El cheapo 2 GB CF card in my main IPCop:

Code:

root@cop:~ # hdparm -Tt /dev/hdc

/dev/hdc:
 Timing cached reads:   448 MB in  2.01 seconds = 222.89 MB/sec
 Timing buffered disk reads:   14 MB in  3.30 seconds =   4.24 MB/sec

For reference, Linux server (AMD X2 BE-2400, 2 GB RAM, 2x 500 GB SATA II)

Code:

# hdparm -Tt /dev/sda

/dev/sda:
 Timing cached reads:   2122 MB in  2.00 seconds = 1061.75 MB/sec
 Timing buffered disk reads:  254 MB in  3.01 seconds =  84.42 MB/sec

I'm not sure, but what will be the negative point for an IPCop, if the CF card(s) will not have more than 10 MB/s?

Not much, 10 MByte/s will still keep your 100 MBit/s Ethernet fairly busy.

[Davesworld]

Even so, other than proxy cache, you'd never notice the slower CF cards except it might take three seconds longer to boot, and they'd never hold up for heavy cache anyway.

The only thing that mystifies me is the expected number of read/write cycles on the Transcend DOM's? I went to their website. I know the Industrial CF card that I use is expected to handle 2,000,000 rw cycles. The doms are touted as industrial as well. I'm sure it will outlive the Raq the way we run the flash images. 

[sven]

Hello Olaf and Dave,

thank you for your informations.
I will look for some Transcend 133x CF Cards that a electronic discounter in town sells for about 16 (4 GB) and 26 Euros (8 GB), 22 MB/s read and 16 MB/s write throughput each (on the paper ).

After that I have to wait until the next kernel update for raqcop. Who (re)boots his cop without a need like a kernel update and gives up his coptime position...

:mrgreen:


Regards
Sven