Alexey Fisher wrote:
Am Freitag, den 30.10.2009, 10:14 -0500 schrieb Eric Sandeen:
...
After a little brief digging I'm not sure when the xfs mount option went
in or why...
But for both
xfs: mount -o ro,norecovery
and
ext[34]: mount -o ro,noload
I don't think either one should touch the disk.
Also, both should skip journal replay if you set the block device
readonly prior to mount (hdparm -r can do this).
Interesting tip, thank you.
But there is some problems:
1. "hdparm -r" will set complete drive to ro mode. This is bad if i
use /dev/sda1 for root and /dev/sda5 need to be forced readonly.
So point it at the partition not the drive:
[root@neon ~]# hdparm -r 1 /dev/sda1
/dev/sda1:
setting readonly to 1 (on)
readonly = 1 (on)
[root@neon ~]# hdparm -r /dev/sda2
/dev/sda2:
readonly = 0 (off)
It doesn't change the hardware, it sets a flag on the kernel's block
device structure.
2. the fact xfs and ext[3,4] use different options for true_ro make
things complicated.
the hazards of being an open source sysadmin I guess.
3. the definition of ro is broken.
depends on what you mean by ro. A user can only read from the
filesystem so it is accurate in that respect. Is "ro" for the fs or the
bdev? Semantic differences but not necessarily broken.
4. many frustrated admins who mounted part of raid1 only with "-o ro"
Dunno what you mean by that ...
-Eric
Regards,
Alexey
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